One way of mapping terrestrial (land) biomes around the world
A biome (/ˈbaɪ.oʊm/) is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate.Biomes may span more than one continent. Biome is a broader term than habitat and can comprise a variety of habitats.
While a biome can cover large areas, a microbiome is a mix of
organisms that coexist in a defined space on a much smaller scale. For
example, the human microbiome is the collection of bacteria, viruses, and other microorganisms that are present on or in a human body.
A 'biota' is the total collection of organisms of a geographic
region or a time period. From local geographic scales and instantaneous
temporal scales all the way up to whole-planet and whole-timescale
spatiotemporal scales. The biotas of the Earth make up the biosphere.
Etymology
The term was suggested in 1916 by Clements, originally as a synonym for biotic community of Möbius (1877). Later, it gained its current definition, based on earlier concepts of phytophysiognomy, formation and vegetation (used in opposition to flora), with the inclusion of the animal element and the exclusion of the taxonomic element of species composition. In 1935, Tansley added the climatic and soil aspects to the idea, calling it ecosystem. The International Biological Program (1964–74) projects popularized the concept of biome.
However, in some contexts, the term biome is used in a different manner. In German literature, particularly in the Walter terminology, the term is used similarly as biotope
(a concrete geographical unit), while the biome definition used in this
article is used as an international, non-regional,
terminology—irrespectively of the continent in which an area is present,
it takes the same biome name—and corresponds to his "zonobiome",
"orobiome" and "pedobiome" (biomes determined by climate zone, altitude
or soil).
In Brazilian literature, the term "biome" is sometimes used as synonym of biogeographic province, an area based on species composition (the term floristic province being used when plant species are considered), or also as synonym of the "morphoclimatic and phytogeographical domain" of Ab'Sáber,
a geographic space with subcontinental dimensions, with the
predominance of similar geomorphologic and climatic characteristics, and
of a certain vegetation form. Both include many biomes in fact.
Classifications
To
divide the world into a few ecological zones is difficult, notably
because of the small-scale variations that exist everywhere on earth and
because of the gradual changeover from one biome to the other. Their
boundaries must therefore be drawn arbitrarily and their
characterization made according to the average conditions that
predominate in them.
A 1978 study on North American grasslands found a positive logistic correlation between evapotranspiration in mm/yr and above-ground net primary production in g/m2/yr. The general results from the study were that precipitation and water use led to above-ground primary production, while solar irradiation
and temperature lead to below-ground primary production (roots), and
temperature and water lead to cool and warm season growth habit.
These findings help explain the categories used in Holdridge's
bioclassification scheme (see below), which were then later simplified
by Whittaker. The number of classification schemes and the variety of
determinants used in those schemes, however, should be taken as strong
indicators that biomes do not fit perfectly into the classification
schemes created.
Holdridge (1947, 1964) life zones
Holdridge
life zone classification scheme. Although conceived as
three-dimensional by its originator, it is usually shown as a
two-dimensional array of hexagons in a triangular frame.
In 1947, the American botanist and climatologist Leslie Holdridge classified climates based on the biological effects of temperature and rainfall on vegetation under the assumption that these two abiotic
factors are the largest determinants of the types of vegetation found
in a habitat. Holdridge uses the four axes to define 30 so-called
"humidity provinces", which are clearly visible in his diagram. While
this scheme largely ignores soil and sun exposure, Holdridge
acknowledged that these were important.
The distribution of vegetation types as a function of mean annual temperature and precipitation.
Whittaker
classified biomes using two abiotic factors: precipitation and
temperature. His scheme can be seen as a simplification of Holdridge's;
more readily accessible, but missing Holdridge's greater specificity.
Whittaker based his approach on theoretical assertions and
empirical sampling. He had previously compiled a review of biome
classifications.
Key definitions for understanding Whittaker's scheme
Physiognomy:
sometimes referring to the plants' appearance; or the biome's apparent
characteristics, outward features, or appearance of ecological
communities or species - including plants.
Biome: a grouping of terrestrial ecosystems on a given continent
that is similar in vegetation structure, physiognomy, features of the
environment and characteristics of their animal communities.
Formation: a major kind of community of plants on a given continent.
Biome-type: grouping of convergent biomes or formations of different continents, defined by physiognomy.
Formation-type: a grouping of convergent formations.
Whittaker's distinction between biome and formation can be simplified: formation is used when applied to plant communities
only, while biome is used when concerned with both plants and animals.
Whittaker's convention of biome-type or formation-type is a broader
method to categorize similar communities.
Whittaker's parameters for classifying biome-types
Whittaker used what he called "gradient analysis" of ecocline
patterns to relate communities to climate on a worldwide scale.
Whittaker considered four main ecoclines in the terrestrial realm.
Intertidal levels: The wetness gradient of areas that are
exposed to alternating water and dryness with intensities that vary by
location from high to low tide
Climatic moisture gradient
Temperature gradient by altitude
Temperature gradient by latitude
Along these gradients, Whittaker noted several trends that allowed him to qualitatively establish biome-types:
The gradient runs from favorable to the extreme, with corresponding changes in productivity.
Changes in physiognomic complexity vary with how favorable of an
environment exists (decreasing community structure and reduction of
stratal differentiation as the environment becomes less favorable).
Trends in the diversity of structure follow trends in species
diversity; alpha and beta species diversities decrease from favorable to
extreme environments.
Each growth-form (i.e. grasses, shrubs, etc.) has its characteristic place of maximum importance along the ecoclines.
The same growth forms may be dominant in similar environments in widely different parts of the world.
Whittaker summed the effects of gradients (3) and (4) to get an
overall temperature gradient and combined this with a gradient (2), the
moisture gradient, to express the above conclusions in what is known as
the Whittaker classification scheme. The scheme graphs average annual
precipitation (x-axis) versus average annual temperature (y-axis) to
classify biome-types.
The multi-authored series Ecosystems of the World, edited by David W. Goodall, provides a comprehensive coverage of the major "ecosystem types or biomes" on Earth:
Terrestrial Ecosystems
Natural Terrestrial Ecosystems
Wet Coastal Ecosystems
Dry Coastal Ecosystems
Polar and Alpine Tundra
Mires: Swamp, Bog, Fen, and Moor
Temperate Deserts and Semi-Deserts
Coniferous Forests
Temperate Deciduous Forests
Natural Grasslands
Heathlands and Related Shrublands
Temperate Broad-Leaved Evergreen Forests
Mediterranean-Type Shrublands
Hot Deserts and Arid Shrublands
Tropical Savannas
Tropical Rain Forest Ecosystems
Wetland Forests
Ecosystems of Disturbed Ground
Managed Terrestrial Ecosystems
Managed Grasslands
Field Crop Ecosystems
Tree Crop Ecosystems
Greenhouse Ecosystems
Bioindustrial Ecosystems
Aquatic Ecosystems
Inland Aquatic Ecosystems
River and Stream Ecosystems
Lakes and Reservoirs
Marine Ecosystems
Intertidal and Littoral Ecosystems
Coral Reefs
Estuaries and Enclosed Seas
Ecosystems of the Continental Shelves
Ecosystems of the Deep Ocean
Managed Aquatic Ecosystems
Managed Aquatic Ecosystems
Underground Ecosystems
Cave Ecosystems
Walter (1976, 2002) zonobiomes
The eponymously-named Heinrich Walter
classification scheme considers the seasonality of temperature and
precipitation. The system, also assessing precipitation and temperature,
finds nine major biome types, with the important climate traits and vegetation types.
The boundaries of each biome correlate to the conditions of moisture
and cold stress that are strong determinants of plant form, and
therefore the vegetation that defines the region. Extreme conditions,
such as flooding in a swamp, can create different kinds of communities
within the same biome.
Zonobiome
Zonal soil type
Zonal vegetation type
ZB I. Equatorial, always moist, little temperature seasonality
ZB IX. Polar, short, cool summers and long, cold winters
Tundra humus soils with solifluction (permafrost soils)
Low, evergreen vegetation, without trees, growing over permanently frozen soils
Schultz (1988) eco-zones
Schultz (1988, 2005) defined nine ecozones (his concept of ecozone is more similar to the concept of biome than to the concept of ecozone of BBC):
polar/subpolar zone
boreal zone
humid mid-latitudes
dry mid-latitudes
subtropics with winter rain
subtropics with year-round rain
dry tropics and subtropics
tropics with summer rain
tropics with year-round rain
Bailey (1989) ecoregions
Robert G. Bailey nearly developed a biogeographical classification system of ecoregions
for the United States in a map published in 1976. He subsequently
expanded the system to include the rest of North America in 1981, and
the world in 1989. The Bailey system, based on climate, is divided into
four domains (polar, humid temperate, dry, and humid tropical), with
further divisions based on other climate characteristics (subarctic,
warm temperate, hot temperate, and subtropical; marine and continental;
lowland and mountain).
A team of biologists convened by the World Wildlife Fund (WWF) developed a scheme that divided the world's land area into biogeographic realms (called "ecozones" in a BBC scheme), and these into ecoregions (Olson & Dinerstein, 1998, etc.). Each ecoregion is characterized by a main biome (also called major habitat type).
This classification is used to define the Global 200 list of ecoregions identified by the WWF as priorities for conservation.
Humans have altered global patterns of biodiversity and ecosystem
processes. As a result, vegetation forms predicted by conventional
biome systems can no longer be observed across much of Earth's land
surface as they have been replaced by crop and rangelands or cities. Anthropogenic biomes
provide an alternative view of the terrestrial biosphere based on
global patterns of sustained direct human interaction with ecosystems,
including agriculture, human settlements, urbanization, forestry and other uses of land.
Anthropogenic biomes offer a way to recognize the irreversible coupling
of human and ecological systems at global scales and manage Earth's
biosphere and anthropogenic biomes.
The endolithic biome, consisting entirely of microscopic life in rock pores
and cracks, kilometers beneath the surface, has only recently been
discovered, and does not fit well into most classification schemes.
Effects of Climate Change
Climate change has the potential to greatly alter the distribution of Earth's biomes. Meaning, biomes around the world could change so much that they would be at risk of becoming new biomes entirely. General frequency models have been a staple in finding out the impact climate change could have on biomes. More specifically, 54% and 22% of global land area will experience climates that correspond to other biomes. 3.6% of land area will experience climates that are completely new or unusual. Average temperatures have risen more than twice the usual amount in both arctic and mountainous biomes. Which leads to the conclusion that artic and mountainous biomes are currently the most vulnerable to climate change.
The current reasoning surrounding as to why this is the case are based
around the fact that colder environments tend to reflect more sunlight,
as a result of the snow and ice covering the ground. Since the annual
average temperatures are rising, ice and snow is melting. As a result, albedo is lowered. Keeping a keen eye on terrestrial biomes is important, as they play a crucial role in climate regulation.
South American terrestrial biomes have been predicted to go through the
same temperature trends as arctic and mountainous biomes. With its annual average temperature continuing to increase, the moisture currently located in forest biomes will dry up.
A nanomotor is a molecular or nanoscale device capable of converting energy into movement. It can typically generate forces on the order of piconewtons.
Magnetically controlled Helical Nanomotor moving inside a HeLa cell drawing a pattern 'N'.
While nanoparticles have been utilized by artists for centuries, such as in the famous Lycurgus cup, scientific research into nanotechnology did not come about until recently. In 1959, Richard Feynman gave a famous talk entitled "There's Plenty of Room at the Bottom"
at the American Physical Society's conference hosted at Caltech. He
went on to wage a scientific bet that no one person could design a motor
smaller than 400 µm on any side.
The purpose of the bet (as with most scientific bets) was to inspire
scientists to develop new technologies, and anyone who could develop a
nanomotor could claim the $1,000 USD prize. However, his purpose was thwarted by William McLellan,
who fabricated a nanomotor without developing new methods. Nonetheless,
Richard Feynman's speech inspired a new generation of scientists to
pursue research into nanotechnology.
Nanomotors are the focus of research for their ability to overcome microfluidic dynamics present at low Reynold's numbers. Scallop Theory
explains that nanomotors must break symmetry to produce motion at low
Reynold's numbers. In addition, Brownian motion must be considered
because particle-solvent interaction can dramatically impact the ability
of a nanomotor to traverse through a liquid. This can pose a
significant problem when designing new nanomotors. Current nanomotor
research seeks to overcome these problems, and by doing so, can improve
current microfluidic devices or give rise to new technologies.
Significant research has been done to overcome microfluidic
dynamics at low Reynolds numbers. Now, the more pressing challenge is to
overcome issues such as biocompatibility, control on directionality and
availability of fuel before nanomotors can be used for theranostic
applications within the body.
In 2004, Ayusman Sen and Thomas E. Mallouk fabricated the first synthetic and autonomous nanomotor.
The two-micron long nanomotors were composed of two segments, platinum
and gold, that could catalytically react with diluted hydrogen peroxide
in water to produce motion. The Au-Pt nanomotors have autonomous, non-Brownian motion that stems from the propulsion via catalytic generation of chemical gradients.
As implied, their motion does not require the presence of an external
magnetic, electric or optical field to guide their motion. By creating their own local fields, these motors are said to move through self-electrophoresis.
Joseph Wang in 2008 was able to dramatically enhance the motion of
Au-Pt catalytic nanomotors by incorporating carbon nanotubes into the
platinum segment.
Since 2004, different types of nanotube and nanowire based motors have been developed, in addition to nano- and micromotors of different shapes. Most of these motors use hydrogen peroxide as fuel, but some notable exceptions exist.
Metallic
microrods (4.3 µm long x 300 nm diameter) can be propelled autonomously
in fluids or inside living cells, without chemical fuel, by resonant
ultrasound. These rods contain a central Ni stripe that can be steered
by an external magnetic field, resulting in "synchronized swimming."
These silver halide and silver-platinum nanomotors are powered by
halide fuels, which can be regenerated by exposure to ambient light. Some nanomotors can even be propelled by multiple stimuli, with varying responses.
These multi-functional nanowires move in different directions depending
on the stimulus (e.g. chemical fuel or ultrasonic power) applied.
For example, bimetallic nanomotors have been shown to undergo rheotaxis
to move with or against fluid flow by a combination of chemical and
acoustic stimuli. In Dresden Germany, rolled-up microtube nanomotors produced motion by harnessing the bubbles in catalytic reactions.
Without the reliance on electrostatic interactions, bubble-induced
propulsion enables motor movement in relevant biological fluids, but
typically still requires toxic fuels such as hydrogen peroxide.
This has limited nanomotors' in vitro applications. One in vivo
application, however, of microtube motors has been described for the
first time by Joseph Wang and Liangfang Zhang using gastric acid as
fuel.
Recently titanium dioxide has also been identified as a potential
candidate for nanomotors due to their corrosion resistance properties
and biocompatibility.
Future research into catalytical nanomotors holds major promise for
important cargo-towing applications, ranging from cell sorting microchip
devices to directed drug delivery.
Recently, there has been more research into developing enzymatic nanomotors and micropumps. At low Reynold's numbers, single molecule enzymes could act as autonomous nanomotors. Ayusman Sen and Samudra Sengupta demonstrated how self-powered micropumps can enhance particle transportation.
This proof-of-concept system demonstrates that enzymes can be
successfully utilized as an "engine" in nanomotors and micropumps.
It has since been shown that particles themselves will diffuse faster
when coated with active enzyme molecules in a solution of their
substrate. Further, it has been seen through microfluidic experiments that enzyme
molecules will undergo directional swimming up their substrate
gradient.
This remains the only method of separating enzymes based on activity
alone. Additionally, enzymes in cascade have also shown aggregation
based on substrate driven chemotaxis. Developing enzyme-driven nanomotors promises to inspire new biocompatible technologies and medical applications.
However, several limitations, such as biocompatibility and
cellpenetration, have to be overcome for realizing these applications. One of the new biocompatible technologies would be to utilize enzymes for the directional delivery of cargo.
A proposed branch of research is the integration of molecular
motor proteins found in living cells into molecular motors implanted in
artificial devices. Such a motor protein would be able to move a "cargo" within that device, via protein dynamics, similarly to how kinesin
moves various molecules along tracks of microtubules inside cells.
Starting and stopping the movement of such motor proteins would involve
caging the ATP
in molecular structures sensitive to UV light. Pulses of UV
illumination would thus provide pulses of movement. DNA nanomachines,
based on changes between two molecular conformations of DNA in response
to various external triggers, have also been described.
Helical nanomotors
Another
interesting direction of research has led to the creation of helical
silica particles coated with magnetic materials that can be maneuvered
using a rotating magnetic field.
Scanning Electron Microscope image of a Helical nanomotor
Such nanomotors are not dependent on chemical reactions to fuel the propulsion. A triaxial Helmholtz coil can provide directed rotating field in space. Recent works have shown how such nanomotors can be used to measure viscosity of non-newtonian fluids at a resolution of a few microns.
This technology promises creation of viscosity map inside cells and the
extracellular milieu. Such nanomotors have been demonstrated to move in
blood.
Recently, researchers have managed to controllably move such nanomotors
inside cancer cells allowing them to trace out patterns inside a cell. Nanomotors moving through the tumor microenvironment have demonstrated the presence of sialic acid in the cancer-secreted extracellular matrix.
Current-driven nanomotors (Classical)
In 2003 Fennimore et al. presented the experimental realization of a prototypical current-driven nanomotor.
It was based on tiny gold leaves mounted on multiwalled carbon
nanotubes, with the carbon layers themselves carrying out the motion.
The nanomotor is driven by the electrostatic interaction of the gold
leaves with three gate electrodes where alternate currents are applied.
Some years later, several other groups showed the experimental
realizations of different nanomotors driven by direct currents.
The designs typically consisted of organic molecules adsorbed on a
metallic surface with a scanning-tunneling-microscope (STM) on top of
it. The current flowing from the tip of the STM is used to drive the
directional rotation of the molecule or of a part of it. The operation of such nanomotors relies on classical physics and is related to the concept of Brownian motors. These examples of nanomotors are also known as molecular motors.
Quantum effects in current-driven nanomotors
Due
to their small size, quantum mechanics plays an important role in some
nanomotors. For example, in 2020 Stolz et al. showed the cross-over from
classical motion to quantum tunneling in a nanomotor made of a rotating
molecule driven by the STM's current. Cold-atom-based ac-driven quantum motors have been explored by several authors. Finally, reverse quantum pumping has been proposed as a general strategy towards the design of nanomotors. In this case, the nanomotors are dubbed as adiabatic quantum motors and it was shown that the quantum nature of electrons can be used to improve the performance of the devices.
The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian geologist Alexey Pavlov, and it was first used in English by British ecologist Arthur Tansley in reference to human influences on climax plant communities. The atmospheric scientist Paul Crutzen introduced the term "Anthropocene" in the mid-1970s. The term is sometimes used in the context of pollution produced from human activity since the start of the Agricultural Revolution but also applies broadly to all major human impacts on the environment.
Many of the actions taken by humans that contribute to a heated
environment stem from the burning of fossil fuel from a variety of
sources, such as: electricity, cars, planes, space heating,
manufacturing, or the destruction of forests.
Chart published by NASA depicting CO2 levels from the past 400,000 years.
Overconsumption is a situation where resource use has outpaced the
sustainable capacity of the ecosystem. It can be measured by the ecological footprint,
a resource accounting approach which compares human demand on
ecosystems with the amount of planet matter ecosystems can renew.
Estimates indicate that humanity's current demand is 70%
higher than the regeneration rate of all of the planet's ecosystems
combined. A prolonged pattern of overconsumption leads to environmental
degradation and the eventual loss of resource bases.
Humanity's overall impact on the planet is affected by many
factors, not just the raw number of people. Their lifestyle (including
overall affluence and resource use) and the pollution they generate
(including carbon footprint) are equally important. In 2008, The New York Times
stated that the inhabitants of the developed nations of the world
consume resources like oil and metals at a rate almost 32 times greater
than those of the developing world, who make up the majority of the
human population.
Human civilization has caused the loss of 83% of all wild mammals and half of plants.
The world's chickens are triple the weight of all the wild birds, while
domesticated cattle and pigs outweigh all wild mammals by 14 to 1.
Global meat consumption is projected to more than double by 2050,
perhaps as much as 76%, as the global population rises to more than
9 billion, which will be a significant driver of further biodiversity loss and increased Greenhouse gas emissions.
Population growth and size
Human population from 10000 BCE to 2000 CE, increasing sevenfold after the eighteenth century.
However, attributing overpopulation as a cause of environmental issues is controversial. Demographic projections indicate that population growth is slowing and world population will peak in the 21st century,
and many experts believe that global resources can meet this increased
demand, suggesting a global overpopulation scenario is unlikely. Other
projections have the population continuing to grow into the next
century. While some studies, including the British government's 2021 Economics of Biodiversity review, posit that population growth and overconsumption are interdependent, critics suggest blaming overpopulation for environmental issues can unduly blame poor populations in the Global South or oversimplify more complex drivers, leading some to treat overconsumption as a separate issue.
Advocates for further reducing fertility rates, among them Rodolfo Dirzo and Paul R. Ehrlich,
argue that this reduction should primarily affect the "overconsuming
wealthy and middle classes," with the ultimate goal being to shrink "the
scale of the human enterprise" and reverse the "growthmania" which they
say threatens biodiversity and the "life-support systems of humanity."
The environmental impact of agriculture varies based on the wide
variety of agricultural practices employed around the world. Ultimately,
the environmental impact depends on the production practices of the
system used by farmers. The connection between emissions into the
environment and the farming system is indirect, as it also depends on
other climate variables such as rainfall and temperature.
Lacanja burn
There are two types of indicators of environmental impact:
"means-based", which is based on the farmer's production methods, and
"effect-based", which is the impact that farming methods have on the
farming system or on emissions to the environment. An example of a
means-based indicator would be the quality of groundwater that is
affected by the amount of nitrogen applied to the soil. An indicator reflecting the loss of nitrate to groundwater would be effect-based.
The environmental impact of agriculture involves a variety of
factors from the soil, to water, the air, animal and soil diversity,
plants, and the food itself. Some of the environmental issues that are
related to agriculture are climate change, deforestation, genetic engineering, irrigation problems, pollutants, soil degradation, and waste.
These conservation issues are part of marine conservation, and are addressed in fisheries science
programs. There is a growing gap between how many fish are available to
be caught and humanity's desire to catch them, a problem that gets
worse as the world population grows.
Similar to other environmental issues, there can be conflict between the fishermen who depend on fishing for their livelihoods and fishery scientists who realize that if future fish populations are to be sustainable then some fisheries must reduce or even close.
The journal Science
published a four-year study in November 2006, which predicted that, at
prevailing trends, the world would run out of wild-caught seafood in
2048. The scientists stated that the decline was a result of overfishing,
pollution and other environmental factors that were reducing the
population of fisheries at the same time as their ecosystems were being
degraded. Yet again the analysis has met criticism as being
fundamentally flawed, and many fishery management officials, industry
representatives and scientists challenge the findings, although the
debate continues. Many countries, such as Tonga, the United States,
Australia and New Zealand, and international management bodies have
taken steps to appropriately manage marine resources.
The UN's Food and Agriculture Organization (FAO) released their biennial State of World Fisheries and Aquaculture in 2018
noting that capture fishery production has remained constant for the
last two decades but unsustainable overfishing has increased to 33% of
the world's fisheries. They also noted that aquaculture, the production
of farmed fish, has increased from 120 million tonnes per year in 1990
to over 170 million tonnes in 2018.
Populations of oceanic sharks and rays
have been reduced by 71% since 1970, largely due to overfishing. More
than three-quarters of the species comprising this group are now
threatened with extinction.
The environmental impact of irrigation includes the changes in quantity and quality of soil and water as a result of irrigation and the ensuing effects on natural and social conditions at the tail-end and downstream of the irrigation scheme.
The impacts stem from the changed hydrological conditions owing to the installation and operation of the scheme.
An irrigation scheme often draws water from the river and
distributes it over the irrigated area. As a hydrological result it is
found that:
Effects on soil and water quality are indirect and complex, and subsequent impacts on natural, ecological and socio-economic conditions are intricate. In some, but not all instances, water logging and soil salinization
can result. However, irrigation can also be used, together with soil
drainage, to overcome soil salinization by leaching excess salts from
the vicinity of the root zone.
Irrigation can also be done extracting groundwater by (tube)wells. As a hydrological result it is found that the level of the water descends. The effects may be water mining, land/soil subsidence, and, along the coast, saltwater intrusion.
Irrigation projects can have large benefits, but the negative side effects are often overlooked.
Agricultural irrigation technologies such as high powered water
pumps, dams, and pipelines are responsible for the large-scale depletion
of fresh water resources such as aquifers, lakes, and rivers. As a
result of this massive diversion of freshwater, lakes, rivers, and
creeks are running dry, severely altering or stressing surrounding
ecosystems, and contributing to the extinction of many aquatic species.
Lal and Stewart estimated global loss of agricultural land by degradation and abandonment at 12 million hectares per year.
In contrast, according to Scherr, GLASOD (Global Assessment of
Human-Induced Soil Degradation, under the UN Environment Programme)
estimated that 6 million hectares of agricultural land per year had been
lost to soil degradation since the mid-1940s, and she noted that this
magnitude is similar to earlier estimates by Dudal and by Rozanov et al. Such losses are attributable not only to soil erosion, but also to salinization, loss of nutrients and organic matter, acidification, compaction, water logging and subsidence.
Human-induced land degradation tends to be particularly serious in dry
regions. Focusing on soil properties, Oldeman estimated that about 19
million square kilometers of global land area had been degraded; Dregne
and Chou, who included degradation of vegetation cover as well as soil,
estimated about 36 million square kilometers degraded in the world's dry
regions.
Despite estimated losses of agricultural land, the amount of arable
land used in crop production globally increased by about 9% from 1961 to
2012, and is estimated to have been 1.396 billion hectares in 2012.
Global average soil erosion rates are thought to be high, and
erosion rates on conventional cropland generally exceed estimates of
soil production rates, usually by more than an order of magnitude.
In the US, sampling for erosion estimates by the US NRCS (Natural
Resources Conservation Service) is statistically based, and estimation
uses the Universal Soil Loss Equation and Wind Erosion Equation. For
2010, annual average soil loss by sheet, rill and wind erosion on
non-federal US land was estimated to be 10.7 t/ha on cropland and 1.9
t/ha on pasture land; the average soil erosion rate on US cropland had
been reduced by about 34% since 1982.
No-till and low-till practices have become increasingly common on North
American cropland used for production of grains such as wheat and
barley. On uncultivated cropland, the recent average total soil loss has
been 2.2 t/ha per year.
In comparison with agriculture using conventional cultivation, it has
been suggested that, because no-till agriculture produces erosion rates
much closer to soil production rates, it could provide a foundation for
sustainable agriculture.
Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land. It is viewed as any change or disturbance to the land perceived to be deleterious or undesirable. Natural hazards
are excluded as a cause; however human activities can indirectly affect
phenomena such as floods and bush fires. This is considered to be an
important topic of the 21st century due to the implications land
degradation has upon agronomic productivity, the environment, and its effects on food security. It is estimated that up to 40% of the world's agricultural land is seriously degraded.
Environmental impacts associated with meat production include use of
fossil energy, water and land resources, greenhouse gas emissions, and
in some instances, rainforest clearing, water pollution and species endangerment, among other adverse effects.
Steinfeld et al. of the FAO estimated that 18% of global anthropogenic
GHG (greenhouse gas) emissions (estimated as 100-year carbon dioxide
equivalents) are associated in some way with livestock production. FAO data indicate that meat accounted for 26% of global livestock product tonnage in 2011.
Globally, enteric fermentation (mostly in ruminant livestock) accounts for about 27% of anthropogenic methane emissions, Despite methane's 100-year global warming potential, recently estimated at 28 without and 34 with climate-carbon feedbacks,
methane emission is currently contributing relatively little to global
warming. Although reduction of methane emissions would have a rapid
effect on warming, the expected effect would be small.
Other anthropogenic GHG emissions associated with livestock production
include carbon dioxide from fossil fuel consumption (mostly for
production, harvesting and transport of feed), and nitrous oxide
emissions associated with the use of nitrogenous fertilizers, growing of
nitrogen-fixing legume vegetation and manure management. Management
practices that can mitigate GHG emissions from production of livestock
and feed have been identified.
Considerable water use is associated with meat production, mostly
because of water used in production of vegetation that provides feed.
There are several published estimates of water use associated with
livestock and meat production, but the amount of water use assignable to
such production is seldom estimated. For example, "green water" use is
evapotranspirational use of soil water that has been provided directly
by precipitation; and "green water" has been estimated to account for
94% of global beef cattle production's "water footprint", and on rangeland, as much as 99.5% of the water use associated with beef production is "green water".
Impairment of water quality by manure and other substances in
runoff and infiltrating water is a concern, especially where intensive
livestock production is carried out. In the US, in a comparison of 32
industries, the livestock industry was found to have a relatively good
record of compliance with environmental regulations pursuant to the
Clean Water Act and Clean Air Act,
but pollution issues from large livestock operations can sometimes be
serious where violations occur. Various measures have been suggested by
the US Environmental Protection Agency, among others, which can help
reduce livestock damage to streamwater quality and riparian
environments.
Changes in livestock production practices influence the
environmental impact of meat production, as illustrated by some beef
data. In the US beef production system, practices prevailing in 2007 are
estimated to have involved 8.6% less fossil fuel use, 16% less
greenhouse gas emissions (estimated as 100-year carbon dioxide
equivalents), 12% less withdrawn water use and 33% less land use, per
unit mass of beef produced, than in 1977.
From 1980 to 2012 in the US, while population increased by 38%, the
small ruminant inventory decreased by 42%, the cattle-and-calves
inventory decreased by 17%, and methane emissions from livestock
decreased by 18%; yet despite the reduction in cattle numbers, US beef production increased over that period.
Some impacts of meat-producing livestock may be considered environmentally beneficial.
These include waste reduction by conversion of human-inedible crop
residues to food, use of livestock as an alternative to herbicides for
control of invasive and noxious weeds and other vegetation management,
use of animal manure as fertilizer as a substitute for those synthetic
fertilizers that require considerable fossil fuel use for manufacture,
grazing use for wildlife habitat enhancement, and carbon sequestration in response to grazing practices, among others. Conversely, according to some studies appearing in
peer-reviewed journals, the growing demand for meat is contributing to significant biodiversity loss as it is a significant driver of deforestation and habitat destruction. Moreover, the 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES also warns that ever increasing land use for meat production plays a significant role in biodiversity loss. A 2006 Food and Agriculture Organization report, Livestock's Long Shadow, found that around 26% of the planet's terrestrial surface is devoted to livestock grazing.
Palm oil
is a type of vegetable oil, found in oil palm trees, which are native
to West and Central Africa. Initially used in foods in developing
countries, palm oil is now also used in food, cosmetic and other types
of products in other nations as well. Over one-third of vegetable oil
consumed globally is palm oil.
Habitat loss
The
rate of global tree cover loss has approximately doubled since 2001, to
an annual loss approaching an area the size of Italy.
The consumption of palm oil in food, domestic and cosmetic products
all over the world means there is a high demand for it. To meet this,
oil palm plantations are created, which means removing natural forests
to clear space. This deforestation
has taken place in Asia, Latin America and West Africa, with Malaysia
and Indonesia holding 90% of global oil palm trees. These forests are
home to a wide range of species, including many endangered animals, ranging from birds to rhinos and tigers.
Since 2000, 47% of deforestation has been for the purpose of growing
oil palm plantations, with around 877,000 acres being affected per year.
Impact on biodiversity
Natural forests are extremely biodiverse,
with a wide range of organisms using them as their habitat. But oil
palm plantations are the opposite. Studies have shown that oil palm
plantations have less than 1% of the plant diversity seen in natural
forests, and 47–90% less mammal diversity.
This is not because of the oil palm itself, but rather because the oil
palm is the only habitat provided in the plantations. The plantations
are therefore known as a monoculture,
whereas natural forests contain a wide variety of flora and fauna,
making them highly biodiverse. One of the ways palm oil could be made
more sustainable (although it is still not the best option) is through agroforestry, whereby the plantations are made up of multiple types of plants used in trade – such as coffee or cocoa.
While these are more biodiverse than monoculture plantations, they are
still not as effective as natural forests. In addition to this,
agroforestry does not bring as many economic benefits to workers, their
families and the surrounding areas.
Roundtable on Sustainable Palm Oil (RSPO)
The
RSPO is a non-profit organisation that has developed criteria that its
members (of which, as of 2018, there are over 4,000) must follow to
produce, source and use sustainable palm oil (Certified Sustainable Palm
Oil; CSPO). Currently, 19% of global palm oil is certified by the RSPO
as sustainable.
The CSPO criteria states that oil palm plantations cannot be
grown in the place of forests or other areas with endangered species,
fragile ecosystems, or those that facilitate the needs of local
communities. It also calls for a reduction in pesticides and fires, along with several rules for ensuring the social wellbeing of workers and the local communities.
Human activity is causing environmental degradation, which is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction
of wildlife; and pollution. It is defined as any change or disturbance
to the environment perceived to be deleterious or undesirable. As indicated by the I=PAT
equation, environmental impact (I) or degradation is caused by the
combination of an already very large and increasing human population
(P), continually increasing economic growth or per capita affluence (A),
and the application of resource-depleting and polluting technology (T).
According to a 2021 study published in Frontiers in Forests and Global Change, roughly 3% of the planet's terrestrial surface is ecologically and faunally
intact, meaning areas with healthy populations of native animal species
and little to no human footprint. Many of these intact ecosystems were
in areas inhabited by indigenous peoples.
According to a 2018 study in Nature,
87% of the oceans and 77% of land (excluding Antarctica) have been
altered by anthropogenic activity, and 23% of the planet's landmass
remains as wilderness.
Habitat fragmentation is the reduction of large tracts of habitat leading to habitat loss. Habitat fragmentation and loss are considered as being the main cause of the loss of biodiversity
and degradation of the ecosystem all over the world. Human actions are
greatly responsible for habitat fragmentation, and loss as these actions
alter the connectivity and quality of habitats. Understanding the
consequences of habitat fragmentation is important for the preservation
of biodiversity and enhancing the functioning of the ecosystem.
Both agricultural plants and animals depend on pollination for
reproduction. Vegetables and fruits are an important diet for human
beings and depend on pollination. Whenever there is habitat destruction,
pollination is reduced and crop yield as well. Many plants also rely on
animals and most especially those that eat fruit for seed dispersal.
Therefore, the destruction of habitat for animal severely affects all
the plant species that depend on them.
Biodiversity generally refers to the variety and variability of life
on Earth, and is represented by the number of different species there
are on the planet. Since its introduction, Homo sapiens (the human
species) has been killing off entire species either directly (such as
through hunting) or indirectly (such as by destroying habitats), causing the extinction of species at an alarming rate. Humans are the cause of the current mass extinction, called the Holocene extinction, driving extinctions to 100 to 1000 times the normal background rate.
Though most experts agree that human beings have accelerated the rate
of species extinction, some scholars have postulated without humans, the
biodiversity of the Earth would grow at an exponential rate rather than
decline. The Holocene extinction continues, with meat consumption, overfishing, ocean acidification and the amphibian crisis being a few broader examples of an almost universal, cosmopolitan decline in biodiversity. Human overpopulation (and continued population growth) along with profligate consumption are considered to be the primary drivers of this rapid decline. The 2017 World Scientists' Warning to Humanity
stated that, among other things, this sixth extinction event unleashed
by humanity could annihilate many current life forms and consign them to
extinction by the end of this century. A 2022 scientific review published in Biological Reviews
confirms that a biodiversity loss crisis caused by human activity,
which the researchers describe as a sixth mass extinction event, is
currently underway.
A June 2020 study published in PNAS
argues that the contemporary extinction crisis "may be the most serious
environmental threat to the persistence of civilization, because it is
irreversible" and that its acceleration "is certain because of the still
fast growth in human numbers and consumption rates."
High-level political attention on the environment has been focused
largely on climate change because energy policy is central to economic
growth. But biodiversity is just as important for the future of earth as
climate change.
Summary
of major biodiversity-related environmental-change categories expressed
as a percentage of human-driven change (in red) relative to baseline
(blue)
Defaunation is the loss of animals from ecological communities.
It has been estimated that from 1970 to 2016, 68% of the world's wildlife has been destroyed due to human activity. In South America, there is believed to be a 70 percent loss. A May 2018 study published in PNAS
found that 83% of wild mammals, 80% of marine mammals, 50% of plants
and 15% of fish have been lost since the dawn of human civilization.
Currently, livestock make up 60% of the biomass of all mammals on earth, followed by humans (36%) and wild mammals (4%). According to the 2019 global biodiversity assessment by IPBES,
human civilization has pushed one million species of plants and animals
to the brink of extinction, with many of these projected to vanish over
the next few decades.
When plant biodiversity declines, the remaining plants face diminishing productivity. Biodiversity loss threatens ecosystem productivity and services such as food, fresh water, raw materials and medicinal resources.
A 2019 report that assessed a total of 28,000 plant species
concluded that close to half of them were facing a threat of extinction.
The failure of noticing and appreciating plants is regarded as "plant
blindness", and this is a worrying trend as it puts more plants at the
threat of extinction than animals. Our increased farming has come at a
higher cost to plant biodiversity as half of the habitable land on Earth
is used for agriculture, and this is one of the major reasons behind
the plant extinction crisis.
Invasive species are defined by the U.S. Department of Agriculture as
non-native to the specific ecosystem, and whose presence is likely to
harm the health of humans or the animals in said system.
Introductions of non-native species into new areas have brought
about major and permanent changes to the environment over large areas.
Examples include the introduction of Caulerpa taxifolia
into the Mediterranean, the introduction of oat species into the
California grasslands, and the introduction of privet, kudzu, and purple loosestrife
to North America. Rats, cats, and goats have radically altered
biodiversity in many islands. Additionally, introductions have resulted
in genetic changes to native fauna where interbreeding has taken place,
as with buffalo with domestic cattle, and wolves with domestic dogs.
Human Introduced Invasive Species
Cats
Domestic
and feral cats globally are particularly notorious for their
destruction of native birds and other animal species. This is especially
true for Australia, which attributes over two-thirds of mammal
extinction to domestic and feral cats, and over 1.5 billion deaths to
native animals each year.
Because domesticated outside cats are fed by their owners, they can
continue to hunt even when prey populations decline and they would
otherwise go elsewhere. This is a major problem for places where there
is a highly diverse and dense number of lizards, birds, snakes, and mice
populating the area.
Roaming outdoor cats can also be attributed to the transmission of
harmful diseases like rabies and toxoplasmosis to the native wildlife
population.
Burmese Python
Another example of a destructive introduced invasive species is the Burmese Python. Originating from parts of Southeast Asia, the Burmese Python has made the most notable impact in the Southern Florida Everglades
of the United States. After a breeding facility breach in 1992 due to
flooding and snake owners releasing unwanted pythons back into the wild,
the population of the Burmese Python would boom in the warm climate of
Florida in the following years.
This impact has been felt most significantly at the southernmost
regions of the Everglades. A study in 2012 compared native species
population counts in Florida from 1997 and found that raccoon
populations declined 99.3%, opossums 98.9%, and rabbit/fox populations
effectively disappeared.
Human activities have significant impact on coral reefs. Coral reefs are dying around the world.Damaging activities include coral mining, pollution (organic and non-organic), overfishing, blast fishing, the digging of canals and access into islands and bays. Other threats include disease, destructive fishing practices and warming oceans. The ocean's role as a carbon dioxide sink, atmospheric changes, ultraviolet light, ocean acidification, viruses, impacts of dust storms carrying agents to far-flung reefs, pollutants, algal blooms
are some of the factors that affect coral reefs. Evidently, coral reefs
are threatened well beyond coastal areas. Climate change, such as global warming causes coral bleaching which can be fatal to the corals.
Scientists estimate that over next 20 years, about 70 to 90% of all
coral reefs will disappear. With primary causes being warming ocean
waters, ocean acidity, and pollution. In 2008, a worldwide study estimated that 19% of the existing area of coral reefs had already been lost. Only 46% of the world's reefs could be currently regarded as in good health
and about 60% of the world's reefs may be at risk due to destructive,
human-related activities. The threat to the health of reefs is
particularly strong in Southeast Asia, where 80% of reefs are endangered. By the 2030s, 90% of reefs are expected to be at risk from both human activities and climate change; by 2050, it is predicted that all coral reefs will be in danger.
Domestic, industrial and agricultural wastewater can be treated in wastewater treatment plants
for treatment before being released into aquatic ecosystems. Treated
wastewater still contains a range of different chemical and biological
contaminants which may influence surrounding ecosystems.
The primary causes and the wide-ranging effects of global warming and resulting climate change. Some effects constitute feedbacks that intensify climate change.
Contemporary climate change
is the result of increasing atmospheric greenhouse gas concentrations,
which is caused primarily by combustion of fossil fuel (coal, oil,
natural gas), and by deforestation, land use changes, and cement
production. Such massive alteration of the global carbon cycle
has only been possible because of the availability and deployment of
advanced technologies, ranging in application from fossil fuel
exploration, extraction, distribution, refining, and combustion in power
plants and automobile engines and advanced farming practices. Livestock
contributes to climate change both through the production of greenhouse
gases and through destruction of carbon sinks
such as rain-forests. According to the 2006 United Nations/FAO report,
18% of all greenhouse gas emissions found in the atmosphere are due to
livestock. The raising of livestock and the land needed to feed them has
resulted in the destruction of millions of acres of rainforest and as
global demand for meat rises, so too will the demand for land.
Ninety-one percent of all rainforest land deforested since 1970 is now
used for livestock.
Potential negative environmental impacts caused by increasing
atmospheric carbon dioxide concentrations are rising global air
temperatures, altered hydrogeological cycles resulting in more frequent
and severe droughts, storms, and floods, as well as sea level rise and
ecosystem disruption.
The fossils that are burned by humans for energy usually come back to
them in the form of acid rain. Acid rain is a form of precipitation
which has high sulfuric and nitric acids which can occur in the form of a
fog or snow. Acid rain has numerous ecological impacts on streams,
lakes, wetlands
and other aquatic environments. It damages forests, robs the soil of
its essential nutrients, releases aluminium to the soil, which makes it
very hard for trees to absorb water.
Researchers have discovered that kelp, eelgrass and other
vegetation can effectively absorb carbon dioxide and hence reducing
ocean acidity. Scientists, therefore, say that growing these plants
could help in mitigating the damaging effects of acidification on marine
life.
Ozone depletion
Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, and a much larger springtime decrease in stratospheric ozone (the ozone layer) around Earth's polar regions. The latter phenomenon is referred to as the ozone hole. There are also springtime polar tropospheric ozone depletion events in addition to these stratospheric events.
The main causes of ozone depletion and the ozone hole are manufactured chemicals, especially manufactured halocarbonrefrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons), referred to as ozone-depleting substances (ODS). These compounds are transported into the stratosphere by turbulent mixing after being emitted from the surface, mixing much faster than the molecules can settle. Once in the stratosphere, they release atoms from the halogen group through photodissociation, which catalyze the breakdown of ozone (O3) into oxygen (O2). Both types of ozone depletion were observed to increase as emissions of halocarbons increased.
Ozone depletion and the ozone hole have generated worldwide
concern over increased cancer risks and other negative effects. The
ozone layer prevents harmful wavelengths of ultraviolet (UVB) light from passing through the Earth's atmosphere. These wavelengths cause skin cancer, sunburn, permanent blindness, and cataracts,
which were projected to increase dramatically as a result of thinning
ozone, as well as harming plants and animals. These concerns led to the
adoption of the Montreal Protocol in 1987, which bans the production of CFCs, halons, and other ozone-depleting chemicals.
The ban came into effect in 1989. Ozone levels stabilized by the
mid-1990s and began to recover in the 2000s, as the shifting of the jet stream in the southern hemisphere towards the south pole has stopped and might even be reversing.
Recovery is projected to continue over the next century, and the ozone
hole is expected to reach pre-1980 levels by around 2075. In 2019, NASA reported that the ozone hole was the smallest ever since it was first discovered in 1982.
The Montreal Protocol is considered the most successful international environmental agreement to date.
Of particular concern is N2O, which has an average atmospheric lifetime of 114–120 years, and is 300 times more effective than CO2 as a greenhouse gas. NOx produced by industrial processes, automobiles and agricultural fertilization and NH3 emitted from soils (i.e., as an additional byproduct of nitrification)
and livestock operations are transported to downwind ecosystems,
influencing N cycling and nutrient losses. Six major effects of NOx and NH3 emissions have been identified:
decreased atmospheric visibility due to ammonium aerosols (fine particulate matter [PM])
The applications of technology often result in unavoidable and unexpected environmental impacts, which according to the I = PAT
equation is measured as resource use or pollution generated per unit
GDP. Environmental impacts caused by the application of technology are
often perceived as unavoidable for several reasons. First, given that
the purpose of many technologies is to exploit, control, or otherwise
"improve" upon nature for the perceived benefit of humanity while at the
same time the myriad of processes in nature have been optimized and are
continually adjusted by evolution, any disturbance of these natural
processes by technology is likely to result in negative environmental
consequences. Second, the conservation of mass principle and the first law of thermodynamics
(i.e., conservation of energy) dictate that whenever material resources
or energy are moved around or manipulated by technology, environmental
consequences are inescapable. Third, according to the second law of thermodynamics, order can be increased within a system (such as the human economy) only by increasing disorder or entropy
outside the system (i.e., the environment). Thus, technologies can
create "order" in the human economy (i.e., order as manifested in
buildings, factories, transportation networks, communication systems,
etc.) only at the expense of increasing "disorder" in the environment.
According to a number of studies, increased entropy is likely to be
correlated to negative environmental impacts.
The environmental impact of mining includes erosion, formation of sinkholes, loss of biodiversity, and contamination of soil, groundwater and surface water
by chemicals from mining processes. In some cases, additional forest
logging is done in the vicinity of mines to increase the available room
for the storage of the created debris and soil.
Even though plants need some heavy metals for their growth,
excess of these metals is usually toxic to them. Plants that are
polluted with heavy metals usually depict reduced growth, yield and
performance. Pollution by heavy metals decreases the soil organic matter
composition resulting in a decline in soil nutrients which then leads
to a decline in the growth of plants or even death.
Besides creating environmental damage, the contamination
resulting from leakage of chemicals also affect the health of the local
population.
Mining companies in some countries are required to follow environmental
and rehabilitation codes, ensuring the area mined is returned to close
to its original state. Some mining methods may have significant
environmental and public health effects. Heavy metals usually exhibit
toxic effects towards the soil biota,
and this is through the affection of the microbial processes and
decreases the number as well as activity of soil microorganisms. Low
concentration of heavy metals also has high chances of inhibiting the
plant's physiological metabolism.
In the real world, consumption of fossil fuel resources leads to global warming and climate change. However, little change is being made in many parts of the world. If the peak oil theory proves true, more explorations of viable alternative energy sources, could be more friendly to the environment.
Rapidly advancing technologies can achieve a transition of energy
generation, water and waste management, and food production towards
better environmental and energy usage practices using methods of systems ecology and industrial ecology.
The environmental impact of biodiesel
includes energy use, greenhouse gas emissions and some other kinds of
pollution. A joint life cycle analysis by the US Department of
Agriculture and the US Department of Energy found that substituting 100%
biodiesel for petroleum diesel in buses reduced life cycle consumption
of petroleum by 95%. Biodiesel reduced net emissions of carbon dioxide
by 78.45%, compared with petroleum diesel. In urban buses, biodiesel
reduced particulate emissions 32 percent, carbon monoxide emissions 35
percent, and emissions of sulfur oxides 8%, relative to life cycle
emissions associated with use of petroleum diesel. Life cycle emissions
of hydrocarbons were 35% higher and emission of various nitrogen oxides
(NOx) were 13.5% higher with biodiesel.
Life cycle analyses by the Argonne National Laboratory have indicated
reduced fossil energy use and reduced greenhouse gas emissions with
biodiesel, compared with petroleum diesel use.
Biodiesel derived from various vegetable oils (e.g. canola or soybean
oil), is readily biodegradable in the environment compared with
petroleum diesel.
The environmental impact of coal mining and -burning is diverse. Legislation passed by the US Congress in 1990 required the United States Environmental Protection Agency (EPA) to issue a plan to alleviate toxic air pollution from coal-fired power plants. After delay and litigation, the EPA now has a court-imposed deadline of 16 March 2011, to issue its report.
Electric power systems
consist of generation plants of different energy sources, transmission
networks, and distribution lines. Each of these components can have
environmental impacts at multiple stages of their development and use
including in their construction, during the generation of electricity,
and in their decommissioning and disposal. These impacts can be split
into operational impacts (fuel sourcing, global atmospheric and
localized pollution) and construction impacts (manufacturing,
installation, decommissioning, and disposal). All forms of electricity
generation have some form of environmental impact. This page is organized by energy source and includes impacts such as
water usage, emissions, local pollution, and wildlife displacement.
More detailed information on electricity generation impacts for specific
technologies and on other environmental impacts of electric power
systems in general can be found under the Category:Environmental impact of the energy industry.
The environmental impact of nuclear power results from the nuclear fuel cycle processes including mining, processing, transporting and storing fuel and radioactive fuel waste. Released radioisotopes
pose a health danger to human populations, animals and plants as
radioactive particles enter organisms through various transmission
routes.
Radiation is a carcinogen
and causes numerous effects on living organisms and systems. The
environmental impacts of nuclear power plant disasters such as the Chernobyl disaster, the Fukushima Daiichi nuclear disaster and the Three Mile Island accident,
among others, persist indefinitely, though several other factors
contributed to these events including improper management of fail safe
systems and natural disasters putting uncommon stress on the generators.
The radioactive decay rate of particles varies greatly, dependent upon
the nuclear properties of a particular isotope. Radioactive Plutonium-244
has a half-life of 80.8 million years, which indicates the time
duration required for half of a given sample to decay, though very
little plutonium-244 is produced in the nuclear fuel cycle and lower
half-life materials have lower activity thus giving off less dangerous
radiation.
Oil shale industry
Kiviõli Oil Shale Processing & Chemicals Plant in ida-Virumaa, Estonia
The environmental impact of petroleum is often negative because it is toxic
to almost all forms of life. Petroleum, a common word for oil or
natural gas, is closely linked to virtually all aspects of present
society, especially for transportation and heating for both homes and
for commercial activities.
The environmental impact of reservoirs is coming under ever
increasing scrutiny as the world demand for water and energy increases
and the number and size of reservoirs increases.
Dams and the reservoirs can be used to supply drinking water, generate hydroelectric power, increasing the water supply for irrigation,
provide recreational opportunities and flood control. However, adverse
environmental and sociological impacts have also been identified during
and after many reservoir constructions. Although the impact varies
greatly between different dams and reservoirs, common criticisms include
preventing sea-run fish from reaching their historical mating grounds,
less access to water downstream, and a smaller catch for fishing
communities in the area. Advances in technology have provided solutions
to many negative impacts of dams but these advances are often not viewed
as worth investing in if not required by law or under the threat of
fines. Whether reservoir projects are ultimately beneficial or
detrimental—to both the environment and surrounding human populations—
has been debated since the 1960s and probably long before that. In 1960
the construction of Llyn Celyn and the flooding of Capel Celyn provoked political uproar which continues to this day. More recently, the construction of Three Gorges Dam
and other similar projects throughout Asia, Africa and Latin America
have generated considerable environmental and political debate.
Onshore (on-land) wind farms can have a significant visual impact and impact on the landscape. Due to a very low surface power density and spacing requirements, wind farms typically need to be spread over more land than other power stations. Their network of turbines, access roads, transmission lines, and substations can result in "energy sprawl"; although land between the turbines and roads can still be used for agriculture.
Conflicts arise especially in scenic and culturally-important landscapes. Siting restrictions (such as setbacks) may be implemented to limit the impact. The land between the turbines and access roads can still be used for farming and grazing. They also need to be built away from urban areas, which can lead to "industrialization of the countryside". Some wind farms are opposed for potentially spoiling protected scenic areas, archaeological landscapes and heritage sites. A report by the Mountaineering Council of Scotland concluded that wind farms harmed tourism in areas known for natural landscapes and panoramic views.
Habitat loss and fragmentation are the greatest potential impacts on wildlife of onshore wind farms, but they are small and can be mitigated if proper monitoring and mitigation strategies are implemented. The worldwide ecological impact is minimal. Thousands of birds and bats, including rare species, have been killed by wind turbine blades,
as there are around other manmade structures, though wind turbines are
responsible for far fewer bird deaths than fossil-fueled power stations. This can be mitigated with proper wildlife monitoring.
Many wind turbine blades are made of fiberglass and some only had a lifetime of 10 to 20 years. Previously, there was no market for recycling these old blades, and they were commonly disposed of in landfills.
Because blades are hollow, they take up a large volume compared to
their mass. Since 2019, some landfill operators have begun requiring
blades to be crushed before being landfilled. Blades manufactured in the 2020s are more likely to be designed to be completely recyclable.
Wind turbines also generate noise. At a distance of 300 metres (980 ft)
this may be around 45 dB, which is slightly louder than a refrigerator.
At 1.5 km (1 mi) distance they become inaudible. There are anecdotal reports of negative health effects on people who live very close to wind turbines. Peer-reviewed research has generally not supported these claims. Pile-driving to construct non-floating wind farms is noisy underwater, but in operation offshore wind is much quieter than ships.
Manufacturing
Waste generation, measured in kilograms per person per day
Nanotechnology's
environmental impact can be split into two aspects: the potential for
nanotechnological innovations to help improve the environment, and the
possibly novel type of pollution that nanotechnological materials might
cause if released into the environment. As nanotechnology is an emerging
field, there is great debate regarding to what extent industrial and
commercial use of nanomaterials will affect organisms and ecosystems.
The environmental impact of paint is diverse. Traditional painting materials and processes can have harmful effects on the environment,
including those from the use of lead and other additives. Measures can
be taken to reduce environmental impact, including accurately estimating
paint quantities so that wastage is minimized, use of paints, coatings,
painting accessories and techniques that are environmentally preferred.
The United States Environmental Protection Agency guidelines and Green Star ratings are some of the standards that can be applied.
Paper
A pulp and paper mill in New Brunswick,
Canada. Although pulp and paper manufacturing requires large amounts of
energy, a portion of it comes from burning wood residue.
The environmental effects of paper are significant, which has led to changes in industry and behaviour at both business and personal levels. With the use of modern technology such as the printing press and the highly mechanized harvesting of wood, disposable paper became a relatively cheap commodity, which led to a high level of consumption and waste. The rise in global environmental issues such as air and water pollution, climate change, overflowing landfills and clearcutting have all lead to increased government regulations. There is now a trend towards sustainability in the pulp and paper industry as it moves to reduce clear cutting, water use, greenhouse gas emissions, fossil fuel consumption and clean up its influence on local water supplies and air pollution.
According to a Canadian citizens' organization, "People need
paper products and we need sustainable, environmentally safe
production."
Environmental product declarations or product scorecards are
available to collect and evaluate the environmental and social
performance of paper products, such as the Paper Calculator, Environmental Paper Assessment Tool (EPAT), or Paper Profile.
Both the U.S. and Canada generate interactive maps of environmental
indicators which show pollution emissions of individual facilities.
Some scientists suggest that by 2050 there could be more plastic than fish in the oceans. A December 2020 study published in Nature found that human-made materials, or anthropogenic mass, exceeds all living biomass on earth, with plastic alone outweighing the mass of all terrestrial and marine animals combined.
The environmental impact of pesticides
is often greater than what is intended by those who use them. Over 98%
of sprayed insecticides and 95% of herbicides reach a destination other
than their target species, including nontarget species, air, water,
bottom sediments, and food.
Pesticide contaminates land and water when it escapes from production
sites and storage tanks, when it runs off from fields, when it is
discarded, when it is sprayed aerially, and when it is sprayed into
water to kill algae.
The amount of pesticide that migrates from the intended
application area is influenced by the particular chemical's properties:
its propensity for binding to soil, its vapor pressure, its water solubility, and its resistance to being broken down over time.
Factors in the soil, such as its texture, its ability to retain water,
and the amount of organic matter contained in it, also affect the amount
of pesticide that will leave the area. Some pesticides contribute to global warming and the depletion of the ozone layer.
PPCPs have been detected in water bodies throughout the world. More research is needed to evaluate the risks of toxicity, persistence, and bioaccumulation,
but the current state of research shows that personal care products
impact over the environment and other species, such as coral reefs and fish. PPCPs encompass environmental persistent pharmaceutical pollutants (EPPPs) and are one type of persistent organic pollutants. They are not removed in conventional sewage treatment plants but require a fourth treatment stage which not many plants have.
In 2022, the most comprehensive study of pharmaceutical pollution of the world's rivers found that it threatens
"environmental and/or human health in more than a quarter of the
studied locations". It investigated 1,052 sampling sites along 258
rivers in 104 countries, representing the river pollution of 470 million
people. It found that "the most contaminated sites were in low- to
middle-income countries and were associated with areas with poor
wastewater and waste management infrastructure and pharmaceutical manufacturing" and lists the most frequently detected and concentrated pharmaceuticals.
The environmental impact of transport is significant because it is a major user of energy, and burns most of the world's petroleum. This creates air pollution, including nitrous oxides and particulates, and is a significant contributor to global warming through emission of carbon dioxide, for which transport is the fastest-growing emission sector. By subsector, road transport is the largest contributor to global warming.
Environmental regulations
in developed countries have reduced the individual vehicles emission;
however, this has been offset by an increase in the number of vehicles,
and more use of each vehicle. Some pathways to reduce the carbon emissions of road vehicles considerably have been studied. Energy use and emissions vary largely between modes, causing environmentalists to call for a transition from air and road to rail and human-powered transport, and increase transport electrification and energy efficiency.
Other environmental impacts of transport systems include traffic congestion and automobile-oriented urban sprawl,
which can consume natural habitat and agricultural lands. By reducing
transportation emissions globally, it is predicted that there will be
significant positive effects on Earth's air quality, acid rain, smog and climate change.
The health impact of transport emissions is also of concern. A
recent survey of the studies on the effect of traffic emissions on
pregnancy outcomes has linked exposure to emissions to adverse effects
on gestational duration and possibly also intrauterine growth.
There is an ongoing debate about possible taxation of air travel and the inclusion of aviation in an emissions trading scheme, with a view to ensuring that the total external costs of aviation are taken into account.
The environmental impact of shipping includes greenhouse gas emissions and oil pollution. In 2007, carbon dioxide emissions from shipping were estimated at 4 to 5% of the global total, and estimated by the International Maritime Organization (IMO) to rise by up to 72% by 2020 if no action is taken.
There is also a potential for introducing invasive species into new
areas through shipping, usually by attaching themselves to the ship's
hull.
The First Intersessional Meeting of the IMO Working Group on Greenhouse Gas Emissions from Ships took place in Oslo, Norway
on 23–27 June 2008. It was tasked with developing the technical basis
for the reduction mechanisms that may form part of a future IMO regime
to control greenhouse gas emissions from international shipping, and a
draft of the actual reduction mechanisms themselves, for further
consideration by IMO's Marine Environment Protection Committee (MEPC).
General military spending and military activities have marked environmental effects.
The United States military is considered one of the worst polluters in
the world, responsible for over 39,000 sites contaminated with hazardous
materials. Several studies have also found a strong positive correlation between higher military spending and higher carbon emissions
where increased military spending has a larger effect on increasing
carbon emissions in the Global North than in the Global South. Military activities also affect land use and are extremely resource-intensive.
The military does not solely have negative effects on the environment. There are several examples of militaries aiding in land management, conservation, and greening of an area. Additionally, certain military technologies have proven extremely helpful for conservationists and environmental scientists.
As well as the cost to human life and society, there is a significant environmental impact of war. Scorched earth
methods during, or after war have been in use for much of recorded
history but with modern technology war can cause a far greater
devastation on the environment. Unexploded ordnance can render land unusable for further use or make access across it dangerous or fatal.
Light pollution
A composite image of artificial light emissions from Earth at night
Artificial light at night is one of the most obvious physical changes
that humans have made to the biosphere, and is the easiest form of
pollution to observe from space.
The main environmental impacts of artificial light are due to light's
use as an information source (rather than an energy source). The hunting
efficiency of visual predators generally increases under artificial
light, changing predator prey interactions. Artificial light also affects dispersal, orientation, migration, and hormone levels, resulting in disrupted circadian rhythms.
Fast fashion has become one of the most successful industries in many capitalist societies with the increase in globalisation. Fast fashion is the cheap mass production of clothing, which is then sold on at very low prices to consumers. Today, the industry is worth £2 trillion.
Environmental impacts
In terms of carbon dioxide
emissions, the fast fashion industry contributes between 4–5 billion
tonnes per year, equating to 8–10% of total global emissions. Carbon dioxide is a greenhouse gas,
meaning it causes heat to get trapped in the atmosphere, rather than
being released into space, raising the Earth's temperature – known as global warming.
Alongside greenhouse gas emissions the industry is also responsible for almost 35% of microplastic pollution in the oceans. Scientists have estimated that there are approximately 12–125 trillion tonnes of microplastic particles in the Earth's oceans. These particles are ingested by marine organisms, including fish later eaten by humans.
The study states that many of the fibres found are likely to have come
from clothing and other textiles, either from washing, or degradation.
Textile waste is a huge issue for the environment, with around
2.1 billion tonnes of unsold or faulty clothing being disposed per year.
Much of this is taken to landfill, but the majority of materials used
to make clothes are not biodegradable, resulting in them breaking down and contaminating soil and water.
Fashion, much like most other industries such as agriculture,
requires a large volume of water for production. The rate and quantity
at which clothing is produced in fast fashion means the industry uses
79 trillion litres of water every year. Water consumption has proven to be very detrimental to the environment and its ecosystems,
leading to water depletion and water scarcity. Not only do these affect
marine organisms, but also human's food sources, such as crops. The industry is culpable for roughly one-fifth of all industrial water pollution.
Society and culture
Warnings by the scientific community
There are many publications from the scientific community to warn everyone about growing threats to sustainability, in particular threats to "environmental sustainability". The World Scientists' Warning to Humanity in 1992 begins with: "Human beings and the natural world are on a collision course". About 1,700 of the world's leading scientists, including most Nobel Prize
laureates in the sciences, signed this warning letter. The letter
mentions severe damage to the atmosphere, oceans, ecosystems, soil
productivity, and more. It said that if humanity wants to prevent the
damage, steps need to be taken: better use of resources, abandonment of fossil fuels, stabilization of human population, elimination of poverty and more.
More warning letters were signed in 2017 and 2019 by thousands of
scientists from over 150 countries which called again to reduce overconsumption (including eating less meat), reducing fossil fuels use and other resources and so forth.
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