This article discusses women who have made an important contribution to the field of physics.
Nobel Laureates
1903 Marie Curie:
"in recognition of the extraordinary services they have rendered by
their joint researches on the radiation phenomena discovered by
Professor Henri Becquerel"
1963 Maria Goeppert Mayer: "for their discoveries concerning nuclear shell structure"
c. 150 BCE: Aglaonice became the first female astronomer to be recorded in Ancient Greece.
c. 355–415 CE: Greek astronomer, mathematician and philosopher, Hypatia became renowned as a respected academic teacher, editor of Ptolemy's Almagest astronomical data, and head of her own science academy.
17th century
1668: After separating from her husband, French polymath Marguerite de la Sablière established a popular salon
in Paris. Scientists and scholars from different countries visited the
salon regularly to discuss ideas and share knowledge, and Sablière
studied physics, astronomy and natural history with her guests.
18th century
1732: At the age of 20, Italian physicist Laura Bassi became the first female member of the Bologna Academy of Sciences.
One month later, she publicly defended her academic theses and received
a PhD. Bassi was awarded an honorary position as professor of physics
at the University of Bologna. She was the first female physics professor in the world.
1738: French polymath Émilie du Châtelet became the first woman to have a paper published by the Paris Academy, following a contest on the nature of fire.
1740: Émilie du Châtelet published Institutions de Physique, or Foundations of Physics, providing a metaphysical basis for Newtonian physics.
1751: 19-year-old Italian physicist Cristina Roccati received her PhD from the University of Bologna.
1776: At the University of Bologna, Italian physicist Laura Bassi became the first woman appointed as chair of physics at a university.
1897: American physicist Isabelle Stone
became the first woman to receive a PhD in physics in the United
States. She wrote her dissertation "On the Electrical Resistance of Thin
Films" at the University of Chicago.
1900: Physicists Marie Curie and Isabelle Stone attended the first International Congress of Physics in Paris, France. They were the only two women out of 836 participants.
1909: Danish physicist Kristine Meyer
became the first Danish woman to receive a doctorate degree in natural
sciences. She wrote her dissertation on the topic of "the development of
the temperature concept" within the history of physics.
1910s
1911: Polish-born physicist and chemist Marie Curie became the first woman to receive the Nobel Prize in Chemistry, which she received "[for] the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element". This made her the only woman to win two Nobel Prizes.
1912: American astronomer Henrietta Swan Leavitt studied the bright-dim cycle periods of Cepheid stars, then found a way to calculate the distance from such stars to Earth.
1925: Astronomer and astrophysicist Cecilia Payne-Gaposchkin established that hydrogen is the most common element in stars, and thus the most abundant element in the universe.
1926: The first application of quantum mechanics to molecular systems was done by Lucy Mensing. She studied the rotational spectrum of diatomic molecules using the methods of matrix mechanics.
1947: Berta Karlik, an Austrian physicist, was awarded the Haitinger Prize of the Austrian Academy of Sciences for her discovery of Astatine
1949: Rosemary Brown (later Fowler),
a student of C.F. Powell in Bristol, discovers the k-meson in what
Heisenberg calls "most beautiful" pictures of cosmic ray tracks from the
Jungfraujoch (the 'k' track in Brown, R. et al. Nature, 163, 47 (1949).
This discovery and the prior finding of a very similar particle in 1947
led to the "τ–θ puzzle", the discovery of parity violation in weak
interactions, and hence the Standard Model.
1956: Chinese-American physicist Chien-Shiung Wu conducted a nuclear physics experiment in collaboration with the Low Temperature Group of the US National Bureau of Standards. The experiment, becoming known as the Wu experiment, showed that parity could be violated in weak interaction.
1973: American physicist Anna Coble became the first African-American woman to receive a PhD in biophysics, completing her dissertation at University of Illinois.
1980: Nigerian geophysicist Deborah Ajakaiye became the first woman in any West African country to be appointed a full professor of physics. Over the course of her scientific career, she became the first female Fellow elected to the Nigerian Academy of Science, and the first female dean of science in Nigeria.
2000: Venezuelan astrophysicist Kathy Vivas presented her discovery of approximately 100 "new and very distant" RR Lyrae stars, providing insight into the structure and history of the Milky Way galaxy.
2003: American geophysicist Claudia Alexander oversaw the final stages of Project Galileo, a space exploration mission that ended at the planet Jupiter.
2018: British astrophysicists Hiranya Peiris and Joanna Dunkley and Italian cosmologist Licia Verde were among 27 scientists awarded the Breakthrough Prize in Fundamental Physics
for their contributions to "detailed maps of the early universe that
greatly improved our knowledge of the evolution of the cosmos and the
fluctuations that seeded the formation of galaxies".
2018: British astrophysicist Jocelyn Bell Burnell received the special Breakthrough Prize in Fundamental Physics
for her scientific achievements and “inspiring leadership”, worth $3
million. She donated the entirety of the prize money towards the
creation of scholarships to assist women, underrepresented minorities
and refugees who are pursuing the study of physics.
2020: American astrophysicist Andrea M. Ghez
received the Nobel Prize in Physics "for the discovery of a
supermassive compact object at the centre of our galaxy." She shared
half of the prize with Reinhard Genzel, while the other half was awarded to Roger Penrose.
2020: German geoscientist Ingeborg Levin was the first woman to receive the Alfred Wegener medal from the European Geosciences Union
"for fundamental contributions to our present knowledge and
understanding of greenhouse gases in the atmosphere, including the
global carbon cycle."
2022: French-Swedish physicist Anne L’Huillier received the Wolf Prize in Physics “for pioneering contributions to ultrafast laser science and attosecond physics”.
A carbon offset is a reduction or removal of emissions of carbon dioxide or other greenhouse gases made in order to compensate for emissions made elsewhere. A carbon credit or offset credit is a transferrable financial instrument (i.e. a derivative of an underlying commodity)
certified by governments or independent certification bodies to
represent an emission reduction that can then be bought or sold. Both offsets and credits are measured in tonnes of carbon dioxide-equivalent (CO2e).
One carbon offset or credit represents the reduction or removal of one
ton of carbon dioxide or its equivalent in other greenhouse gases.
Carbon credits are a component of national and international attempts to mitigate the growth in concentrations of greenhouse gases (GHGs). In these programs greenhouse gas emissions are capped and then markets
are used to allocate the emissions among the group of regulated
sources. The goal is to allow market mechanisms to drive these sources
towards lower GHG emissions. Since GHG reduction projects generate
offset credits, this approach can be used to finance carbon reduction schemes
between trading partners around the world. Within the voluntary market,
demand for carbon offsets is generated by individuals, companies,
organizations, and sub-national governments who purchase carbon offsets
to mitigate their greenhouse gas emissions to meet carbon neutral,
net-zero, or other GHG reduction goals. This market is aided by
certification programs that provide standards and other guidance for
project developers to follow in order to generate carbon offsets.
A variety of greenhouse gas reduction projects can be used to
create offsets and credits. Forestry projects are becoming the fastest
growing category. Renewable energy is another common type, and includes wind farms, biomass energy, biogas digesters, or hydroelectric dams. Other types include energy efficiency projects (such as efficient cookstoves), and destruction of landfill methane. Some include methods that use negative emission technologies, such as biochar, carbonated building elements and geologically stored carbon.
Offset and credit programs have been identified as way for
countries to meet their NDC commitments and achieve the goals of the
Paris agreement at a lower cost.
However, there have been a number of news media stories in recent years
criticizing these programs on the grounds that carbon reduction claims
are often exaggerated or misleading. Organizations can take a variety of due diligence
actions to identify "good quality" offsets, ensure that offsetting
provides the desired environmental benefits, and avoid reputation risk
associated with poor quality offsets.
Definitions
A carbon offset is a reduction or removal of emissions of carbon dioxide or other greenhouse gases made in order to compensate for emissions made elsewhere. A carbon credit or offset credit
is a transferrable instrument certified by governments or independent
certification bodies to represent an emission reduction of one metric
ton of CO2, or an equivalent amount of other greenhouse gases (GHGs). Carbon offsets and credits, along with carbon taxes and subsidies, are all forms of carbon pricing.
Historically, the concepts of offsets and credits have been
intertwined. Both offsets and credits can move amongst the various
markets they are traded in.
There are a variety of labels applied to these one-ton emission
reductions, such as "Verified Emission Reduction" or "Certified Emission
Reduction". These depend on the particular program that certifies a
reduction project.
The terminology continues to evolve. At COP27, negotiators agreed
to define offsets and credits issued under Article 6 of the Paris
Agreement as "mitigation contributions", as a means of discouraging
carbon neutrality claims by buyers.
Certification organizations such as the Gold Standard even have
detailed guidance on what descriptive terms are appropriate for buyers
of offsets and credits.
Origins and general features
The
1977 US Clean Air Act created one of the first tradable emission offset
mechanisms. This allowed a permitted facility to increase its emissions
if it paid another company to reduce, by a greater amount, its
emissions of the same pollutant at one or more of its facilities. The 1990 amendments to that same law established the Acid Rain Trading Program.
This introduced the concept of a cap and trade system, where limits on a
pollutant would decrease over time. Within those overall limits,
companies could buy and sell offsets created by other companies that
invested in emission reduction projects. In 1997 the Clean Development Mechanism was created as part of the Kyoto Protocol. This program expanded the concept of emissions trading to a global scale, and focused on the major greenhouse gases that cause climate change. These include: carbon dioxide (CO2), methane, nitrous oxide (N2O), perfluorocarbons, hydrofluorocarbons, and sulfur hexafluoride.
Carbon offsets and credits have several common features:
Vintage. The vintage is the year in which the carbon emissions reduction project generates the carbon offset credit. This is usually done once a third party verifies the project. This can be done by a validation-verification body, a designated operational entity, or other accredited third party reviewers.
However, there is a practice called "Forward Crediting" employed by a
limited number of programs, whereby credits may be issued for projected
emission reductions that the project developer anticipates. This
practice risks over-issuing credits if the project does not realize its
estimated impact, and allows credit buyers to claim emission reductions
in the present for activities that have not yet occurred.
Project type. A variety of projects can be used to reduce GHG
emissions. These can include land-use (e.g. improved forestry
management), methane capture, biomass sequestration, renewable energy,
industrial energy efficiency, and more.
Co-benefits. Beyond reducing greenhouse gas emissions, projects may provide benefits such as ecosystem services
or economic opportunities for communities near the project site. These
project benefits are termed "co-benefits". For example, projects that
reduce agricultural greenhouse gas emissions may improve water quality
by reducing fertilizer usage that results in run-off and may contaminate
water.
Certification regime. The certification regime describes the
systems and procedures that are used to certify and register carbon
offsets and credits. These vary in terms of governance and accounting
practices, project eligibility, environmental integrity and sustainable
development requirements, and Monitoring, Reporting and Verification
(MRV) procedures.
Carbon retirement.
Offset credit holders must "retire" carbon offset credits in order to
claim their associated GHG reductions towards a specific GHG reduction
goal. In the voluntary market, carbon offset registries define the
manner in which retirement happens. Once an offset credit is retired, it
cannot be transferred or used (meaning it is effectively taken out of
circulation).
Voluntary purchasers can also offset their carbon emissions by
purchasing carbon allowances from legally mandated cap-and-trade
programs such as the Regional Greenhouse Gas Initiative or the European Emissions Trading Scheme.
Programs and markets
There is a diverse range of sources of supply, sources of demand, and trading frameworks that drive offset and credit markets. As of 2022, 68 carbon pricing programs were in place or scheduled to be created globally. While some of these involve carbon taxes, many are emission trading programs, or other types of market oriented program involving carbon offsets and credits. International programs include the Clean Development Mechanism, Article 6 of the Paris Agreement, and CORSIA. National programs include ETS systems such as the European Union Emissions Trading System
(EU-ETS) and the California Cap and Trade Program. Eligible credits in
these programs may also include those issued under international or
independent crediting systems. There are also standards and crediting
mechanisms managed by independent, nongovernmental entities, such as
Verra and Gold Standard.
Demand for offsets and credits derives from a range of compliance
obligations established under international agreements and national
laws, as well as voluntary commitments adopted by companies,
governments, and other organizations.
Voluntary carbon markets (VCMs) usually consist of private entities
purchasing carbon offset credits in order to meet voluntary greenhouse
gas reduction commitments. In some cases purchases of credits might also
be done as a non-covered participant in an ETS, as an alternative to
purchasing offsets in a voluntary market.
Currently there are several exchanges trading in carbon credits
and allowances covering both spot and futures markets. These include: Chicago Mercantile Exchange, CTX Global, the European Energy Exchange, Global Carbon Credit Exchange gCCEx, Intercontinental Exchange, MexiCO2, NASDAQ OMX Commodities Europe, Xpansiv.
Many companies now engage in emissions abatement, offsetting, and
sequestration programs to generate credits that can be sold on one of
these exchanges. Some exchanges, such as AirCarbon Exchange and Toucan,
tokenize carbon credits for trading using blockchain technology.
Compliance market credits are the large majority of the offset
and credit market today. In 2021, trading on the VCM was 300 MtCO2e in 2021. By comparison, the compliance carbon market trading volume was 12 GtCO2e,[35] and global greenhouse gas emissions in 2019 were 59 GtCO2e.
Kyoto Protocol and Paris Agreement Article 6 mechanisms
The
original international compliance carbon markets were created as part
of the Kyoto Protocol. That treaty provides for three mechanisms that
enable countries or operators in developed countries to acquire offset
credits The economic basis for these programs was that the marginal cost of reducing emissions would differ among countries.
At the time of the original Kyoto targets, studies suggested that the
flexibility mechanisms could reduce the overall cost of meeting the
targets.
The Kyoto Protocol was to expire in 2020, to be superseded by the Paris
Agreement. The Paris Agreement determinations regarding the role of
carbon offsets are still being determined through international
negotiation specifying the "Article 6" language.
Under the Clean Development Mechanism
(CDM) a developed country can 'sponsor' a greenhouse gas reduction
project in a developing country where the cost of greenhouse gas
reduction project activities is usually much lower, but the atmospheric
effect is globally equivalent.
The developed country is given credits for meeting its emission
reduction targets, while the developing country would receive the
capital investment and clean technology or beneficial change in land use. Once approved, these units are termed Certified Emission Reductions, or CERs. Country specific Designated National Authorities approve projects under this program. Under Joint Implementation
(JI) a developed country with relatively high costs of domestic
greenhouse reduction would set up a project in another developed
country. Offset credits under this program are designated as Emission
Reduction Units. Nuclear energy projects are not eligible for credits under either of these programs. Under the International Emissions Trading (IET) program, countries can trade in the international carbon credit market to cover their shortfall in assigned amount units.
Countries with surplus units can sell them to countries that are
exceeding their emission targets under Annex B of the Kyoto Protocol. Current CDM projects will transfer to new arrangements under the Paris agreement.
Article 6 of the Paris Agreement continues to support offset and
credit programs between countries. These are now carried out to help
achieve emission reduction targets set out in each country's NDC. Under
Article 6, countries will be able to transfer carbon credits earned from
the reduction of GHG emissions to help other countries meet climate
targets. Article 6.2 creates a program for trading GHG emission
reductions via bilateral agreements between countries. Article 6.4 is
expected to be similar to the Clean Development Mechanism of the Kyoto
Protocol. It establishes a centralized program for trading GHG emission
reductions between countries under the supervision of the UNFCCC. Emission reduction (ER) credits purchased under this program can be bought by countries, companies, or even individuals.
Under Article 6.2 the credits (called internationally transferred
mitigation outcomes, or ITMOs) can be transferred from host countries,
where the reduction in GHG is achieved. There are a number of ways this
can be done. Credits can go to credit-buying countries towards
achieving their NDCs. They can also be transferred and used in
market-based schemes such as CORSIA.
To avoid double counting of emission reductions, corresponding
adjustments (CAs) are required. If the receiving country uses ITMOs
towards its NDC, the host country must ‘un-count' those reductions from
its emissions budget by adding and reporting that higher total in its
biennial reporting. Otherwise Article 6.2 provides countries a lot of flexibility in how they can create trading agreements.
Projects under Article 6.4 will be overseen by a "Supervisory
Board" which has the responsibility of approving methodologies, setting
guidance, and implementing procedures. The preparation work for this is
expected to last until the end of 2023. Emission reduction (ER) credits
issued under Article 6.4 will be reduced by 2% in order to ensure that
the program as a whole results in an overall Mitigation of Global
Emissions (OMGE). An additional 5% reduction of Article 6.4 ERs is
dedicated to a fund to finance adaptation. Administrative fees for
program management are still to be determined.
CDM projects are allowed to transition to the Article 6.4 program if
they are approved by the country where the project is located, and if
the project meets the new rules, with the exception of rules on
methodologies. Projects can generally continue to use the same CDM
methodologies through 2025. From 2026 on, they must meet all Article 6
requirements. Up to 2.8 billion credits could potentially become
eligible for issuance under Article 6.4 if all CDM projects were to
transition.
Article 6 does not directly regulate the VCM, and thus in
principle carbon offsets can be issued and purchased without reference
to Article 6. Given the diversity of carbon offsets, a mult-tier system
could emerge with different types of offsets and credits available for
investors. Companies may be to able purchase ‘adjusted credits' that
eliminate the risk of double counting, possibly with higher perceived
value in pursuit of science-based targets and net-zero emissions. Other
‘non-adjusted' offsets and credits could be used to support claims for
other environmental or social indicators, or for emission reductions
that have a lower perceived value in terms of these goals. Uncertainty
remains around Article 6's effects on future voluntary carbon markets
and what investors could claim by purchasing various types of carbon
credits.
Other international programs
The
REDD+ program works to create financial value for carbon stored in
forests by using market approaches to compensate landowners for not
clearing or degrading their forests. REDD+ also promotes co-benefits
from reducing deforestation, such as biodiversity. REDD+ largely
addresses tropical regions in developing countries. The concept of REDD+
was introduced in its basic form at COP11 in 2005. It has evolved and
grown into a broad policy initiative to address deforestation and forest
degradation. In 2015, REDD+ was incorporated into Article 5 of the
Paris Agreement. REDD+ initiatives typically incentivize and compensate
developing countries or subnational entities for reducing their
emissions from deforestation and forest degradation. REDD+ consists of
several stages, including (1) achieving REDD+ readiness; (2) formalizing
an agreement for financing; (3) monitoring, reporting, and verifying
results; and (4) receiving results-based payments. Over 50 countries
have national REDD+ initiatives, mostly developing countries in or
adjacent to the tropics. REDD+ is also being implemented at the
subnational level through provincial and district governments and at the
local level through private landowners. As of 2020, there were over 400
ongoing REDD+ projects globally, with Brazil and Colombia accounting
for the largest amount of REDD+ project land area.
The Carbon Offsetting and Reduction Scheme for International
Aviation (CORSIA) is a global, market-based program to reduce emissions
from international aviation. Its intent is to allow credits and offsets
for emissions that cannot be reduced through the use of technological
and operational improvements, or by the use of sustainable aviation
fuels.
To ensure the environmental integrity of these offsets, the program has
developed a list of eligible offsets that can be used. Operating
principles for the program are similar to those under existing trading
mechanisms and carbon offset certification standards. CORSIA has applied
to international aviation since January 2019, when all airlines were
required to report their CO2 emissions on an annual basis.
International flights have been subject to offsetting obligations under
CORSIA since January 2021.
Emissions trading systems
Emissions trading
has become an important element of regulatory programs to control
pollution, including GHG emissions. GHG emissions trading programs exist
at the sub-national, national, and international level. Under these
programs, emissions are capped, and sources have the flexibility to find
and apply the lowest-cost methods for reducing pollution. A central
authority or governmental
body usually allocates or sells a limited number (a "cap") of permits
that allow a discharge of a specific quantity of a specific pollutant
over a set time period.
Polluters are required to hold permits in amount equal to their
emissions. Those that want to increase their emissions must buy permits
from others willing to sell them.
These programs have been applied to greenhouse gases because their
warming effects are the same regardless of where they are emitted, the
costs of reducing emissions vary widely by source, and the cap ensures
that the environmental goal is attained.
At the start of 2022 there were 25 operational emissions trading
systems around the world, in jurisdictions representing 55% of global
GDP. These systems cover 17% of global emissions. EU-ETS is the second largest trading system in the world after the Chinese national carbon trading scheme, covering over 40% of European GHG emissions. California's cap-and-trade program operates along principles, and covers about 85% of statewide GHG emissions.
Voluntary carbon markets and certification programs
In
voluntary carbon markets, companies or individuals use carbon offsets
in order to meet self-defined goals for reducing emissions. Credits are
issued under independent crediting standards, though some entities also
purchase them under international or domestic crediting mechanisms.
Within the overall market national and subnational programs have been
increasing in popularity.
Many different groups exist within the voluntary carbon market. Participants include developers, brokers, auditors, and buyers.
Certification programs are a key component of this community. These
groups establish accounting standards, project eligibility requirements,
and Monitoring, Reporting and Verification (MRV) procedures for credit
and offset projects. They include the Verified Carbon Standard, the Gold Standard, the Climate Action Reserve, the American Carbon Registry, and Plan Vivo. Puro Standard, the first standard for engineered carbon removal, is verified by DNV GL. There are also some additional standards for the validation of co-benefits, including the CCBS, issued by Verra and the Social Carbon Standard, issued by the Ecologica Institute.
VERRA was developed in 2005, and is a widely used voluntary
carbon standard. As of 2020 there had been over 1,500 certified VCS
projects covering energy, transport, waste, forestry, and other sectors. In 2021 VERRA issued 300 MtCO2e worth of offset credits for 110 projects.
Allowable projects under VERRA include energy, transport, waste, and
forestry. There are also specific methodologies for REDD+ projects.
VERRA is the program of choice for most of the forest credits generated
for the voluntary market, and almost all REDD+ projects.
Due to criticisms of this program, VERRA will be abandoning its current
rules for forestry projects and replacing them with new rules beginning
in 2025.
General VERRA standards cover the types of projects allowed, allowable
project start dates, project boundaries, a 10-year crediting period, as
well as a requirement that the project boundaries cover all primary
effects and significant secondary effects. Verra has additional
criteria to avoid double counting, as well as requirements for
additionality. Negative impacts on sustainable development in the local community are prohibited. It uses accounting principles that include relevance, completeness, consistency, accuracy, transparency, and conservativeness.
The Gold Standard was developed in 2003 by the World Wide Fund
for Nature (WWF) in consultation with an independent Standards Advisory
Board. Projects are open to any non-government, community-based
organization. Allowable project categories include: renewable energy
supply, energy efficiency, afforestation/reforestation, and agriculture. The program's focus includes the promotion of Sustainable Developments Goals.
Projects must meet at least three of those goals, in addition to
reducing GHG emissions, projects must also make a net-positive
contribution to the economic, environmental and social welfare of the
local population. Program monitoring requirements help determine this.
The VCM currently represents less than 1% of the reductions
pledged in country NDCs by 2030, and an even smaller portion of the
reductions needed to achieve the 1.5 °C Paris temperature goal pathway
in 2030.
The VCM is, however, experiencing significant growth. Between 2017 and
2021 both the issuance and retirement of VCM carbon offsets more than
tripled. Some predictions call for global VCM demand to increase 15 fold between 2021 and 2030, and 100 times by 2050. Carbon removal projects such as forestry and carbon capture and storage are expected to have a larger share of this market in the future, compared to renewable energy projects.
However, there is evidence that large companies are becoming more
reluctant to use VCM offsets and credits because of a complex web of
standards, despite an increased focus on net zero goals.
Types of offset projects
A
variety of projects have been used to generate carbon offsets and
credits. These include renewable energy, methane abatement, energy
efficiency, reforestation and fuel switching (i.e. to carbon-neutral fuels and carbon-negative fuels).The CDM identifies over 200 types of projects suitable for generating carbon offsets and credits.
Offset certification and carbon trading programs vary in the
extent to which they consider these specific projects eligible for
offsets or credits.
For example, under the European Union Emission Trading System nuclear
energy projects, afforestation or reforestation activities (LULUCF), and
projects involving destruction of industrial gases (HFC-23 and N2O) are
considered ineligible.
Renewable energy
Renewable
energy projects can include hydroelectric, wind, photovoltaic solar,
solar hot water, biomass power, and heat production projects, among
others. Collectively these types of projects help societies move from
fossil fuel-based electricity and heat production towards less carbon
intensive forms of energy. However, they may not be accepted as offset
projects because it is difficult or impossible to determine their additionality.
They usually generate revenue, and involve subsidies or other complex
financial arrangements. This can make them ineligible under many offset
and credit programs.
Methane collection and combustion
Methane is a potent greenhouse gas. It is most often emitted from landfills, livestock, and from coal mining.
Methane projects can produce carbon offsets through the capture of
methane for energy production. Examples include the combustion or
containment of methane generated by farm animals by use of an anaerobic digester, in landfills, or from other industrial waste.
Energy efficiency
While carbon offsets that fund renewable energy projects help lower the carbon intensity of energy supply, energy conservation projects seek to reduce the overall demand for energy. Carbon offsets in this category fund projects of three main types.
Cogeneration
plants generate both electricity and heat from the same power source,
thus improving upon the energy efficiency of most power plants, which
waste the energy generated as heat. Fuel efficiency
projects replace a combustion device with one using less fuel per unit
of energy provided. This can take the form of both optimized industrial processes (reducing per unit energy costs) and individual action (bicycling to work as opposed to driving). Energy-efficient buildings
reduce the amount of energy wasted in buildings through efficient
heating, cooling or lighting systems. New buildings can also be
constructed using less carbon-intensive input materials.
Destruction of industrial pollutants
Industrial pollutants such as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) have a GWP many thousands of times greater than carbon dioxide by volume.
Because these pollutants are easily captured and destroyed at their
source, they present a large and low-cost source of carbon offsets. As a
category, HFCs, PFCs, and N2O reductions represent 71 percent of offsets issued under the CDM.
Since many of these are now banned by an amendment to the Montreal
Protocol, they are often no longer eligible for offsets or credits.
Land use, land-use change and forestry
Land use, land-use change and forestry (LULUCF) projects focus on natural carbon sinks
such as forests and soil. There are a number of different types of
LULUCF projects. Forestry-related projects focus on avoiding
deforestation by protecting existing forests, restoring forests on land
that was once forested, and creating forests on land that was previously unforested, typically for longer than a generation. Soil management projects attempt to preserve or increase the amount of carbon sequestered in soil.
Deforestation, particularly in Brazil, Indonesia, and parts of Africa,
accounts for about 20 percent of greenhouse gas emissions.
Deforestation can be avoided either by paying directly for forest
preservation, or by using offset funds to provide substitutes for
forest-based products. REDD
(Reducing emissions from deforestation and forest degradation) credits
provide carbon offsets for the protection of forests, and provide a
possible mechanism to allow funding from developed nations to assist in
the protection of native forests in developing nations. Offset schemes
using reforestation are available in developing countries, as well as an
increasing number of developed countries including the US and the UK.
Soil is one of the important aspects of agriculture and can affect
the amount of yield in the crops. Modern agriculture has caused a
decrease in the amount of carbon that the soil is able to hold. Farmers can promote sequestration of carbon in soils through practices such as the use of winter cover crops, reducing the intensity and frequency of tillage, and using compost and manure as soil amendments.
Assuring quality and determining value
Owing
to their indirect nature, many types of offset are difficult to verify.
The credibility of the various certification providers has been
questioned in numerous reports by NGOs and stories in the media. Prices for offsets and credits vary widely. This may be a reflection of the uncertainty associated with these programs and practices. Recently, these issues have caused many companies to become more skeptical of purchasing offsets or credits.
Creating offsets and credits
To
assess the quality of carbon offsets and credits it can be helpful to
understand the typical process used to create them. Before any GHG
reductions can be certified for use as carbon offsets, they must be
shown to meet carbon offset quality criteria. This requires a
methodology or protocol that is specific to the type of offset project
involved. Most carbon offset programs have a library of approved
methodologies covering a range of project types. The next steps involve
project development, validation, and registration. An offset project is
designed by project developers, financed by investors, validated by an
independent verifier, and registered with a carbon offset program.
Official "registration" indicates that the project has been approved by
the program and is eligible to start generating carbon offset credits
after it begins operation.
A commonly used purchasing option is to contract directly with a
project developer for delivery of carbon offset credits as they are
issued. These contracts provide project developers with a level of
certainty about the volume of offset credits they can sell. Buyers are
able to lock in a price for offset credits that is typically lower than
market prices. However, this may involve some risk for them in terms of
the project actually producing offsets.
Once a project is started, it is monitored and periodically
verified to determine the quantity of emission reductions it has
generated. The length of time between verifications can vary, but is
typically one year. A carbon offset program approves verification
reports, and then issues the appropriate number of carbon offset
credits. These are then deposited into the project developer's account
in a registry system administered by the offset program.
Criteria for assessing quality
Criteria for assessing the quality of offsets and credits usually cover the following areas:
Baseline and Measurement—What emissions would occur in the
absence of a proposed project? And how are the emissions that occur
after the project is performed going to be measured?
Additionality—Would
the project occur anyway without the investment raised by selling
carbon offset credits? There are two common reasons why a project may
lack additionality: (a) if it is intrinsically financially worthwhile
due to energy cost savings, and (b) if it had to be performed due to
environmental laws or regulations.
Leakage—Does implementing the project cause higher emissions outside the project boundary?
Permanence—Are some benefits of the reductions reversible? (for
example, trees may be harvested to burn the wood, and does growing trees
for fuel wood decrease the need for fossil fuel?) If woodlands are increasing in area or density, then carbon is being sequestered. After roughly 50 years, forests begin to reach maturity, and remove carbon dioxide more quickly than a recently re-planted forest area.
Double counting—Is the project claimed as carbon offsetting by more than one organization?
Co-benefits—Are there other benefits in addition to the carbon emissions reduction, and to what degree?
Approaches for increasing integrity
In
addition to the certification programs mentioned above, industry groups
have been working since the 2000s to promote the quality of these
projects. The International Carbon Reduction and Offset Alliance (ICROA), founded in 2008, continues to promote best practice across the voluntary carbon market.[105] ICROA's membership consists of carbon offset providers based in the United States, European and Asia-Pacific markets who commit to the ICROA Code of Best Practice.
Other groups are now advocating for new approaches for insuring
the integrity of offsets and credits.The Oxford Offsetting Principles
take the position that traditional carbon offsetting schemes are
"unlikely to deliver the types of offsetting needed to ultimately reach
net zero emissions."
These princiiples focus instead on cutting emissions as a first
priority. In terms of offsets, they advocate for shifting to carbon
removal offset projects that involve long term storage. The principles
also support the development of net zero aligned offsetting. The Science Based Targets initiative's
net-zero criteria also argue for the importance of moving beyond
offsets based on reduced or avoided emissions to offsets based on carbon
that has been sequestered from the atmosphere, such as CO2 Removal Certificates.
Some initiatives are focused improving the quality of current
carbon offset and credit projects. The Integrity Council for the
Voluntary Carbon Market (ICVCM) has published a draft set of principles
for determining a high integrity carbon credit, known as the Core Carbon
Principles. Final guidelines for this program are expected in late
2023. Similarly, the Voluntary Carbon Markets Integrity Iniitiative, funded
in part by the UK government, has developed a code of practice that was
published in 2022.
Determining value
In 2022 voluntary carbon market (VCM) prices ranged from $8 to $30 per ton of CO2e
for the most common types of offset projects. A number of factors can
affect these prices. The costs of developing a project are a
significant factor. Those tied to projects that can sequester carbon
(also called "Nature Based Solutions") have recently been selling at a
premium compared to other projects, such as renewable energy or energy
efficiency. Projects which have additional social and environmental
benefits can command a higher price. This reflects both the value of the
co-benefits as well as the perceived value of association with these
projects. Credits from a reputable organization may command a higher
price. Some credits located in developed countries may be priced higher,
perhaps reflecting company preferences to back projects closer to their
business sites. Conversely, carbon credits with older vintages tend to
be valued lower on the market.
Prices on the compliance market are generally higher and vary
based on geography, with EU and UK ETS credits trading at higher prices
than those in the US in 2022.
Lower prices on the VCM are in part due to an excess of supply in
relation to demand. Some types of offsets are able to be created at very
low costs under present standards. Without this surplus, current VCM
prices could be at least $10/tCO2e higher.
Some pricing forecasts predict VCM prices could increases to as
much as $47–$210 per ton by 2050, with an even higher short term spike
in certain scenarios. A major driver in future price models is the
extent to which programs that support more permanent removals are able
to drive future global climate policy. This could have the effect of
limiting the supply of approvable offsets, and thereby raise prices.
Demand for VCM offsets is expected to increase five to ten-fold
over the next decade as more companies adopt Net Zero climate
commitments. This could be beneficial both for markets and for progress
on reducing GHG emissions. If carbon offset prices remain significantly
below these forecast levels, companies could be open to criticisms of greenwashing, as some might claim credit for emission reduction projects that would have been undertaken anyway. At prices of $100/tCO2e,
a variety of carbon removal technologies (reducing deforestation,
forest restoration, CCS, BECCs and renewables in least developed
countries) could deliver around 2 GtCO2e per year of annual emission reductions between now and 2050.
In addition, as the cost of using offsets and credits rises,
investments in reducing supply chain emissions will become more
attractive.
Effectiveness
Offset
and credit programs have been identified as way for countries to meet
their NDC commitments and achieve the goals of the Paris agreement at a
lower cost.They may also accelerate progress in closing the emissions gap identified in annual UNEP reports.
These programs also produce important co-benefits. Common
environmental co-benefits described for these projects include: better
air quality, increased biodiversity, and water & soil protection.
There are also social benefits, such as community employment
opportunities, energy access, and gender equality. Typical economic
co-benefits include job creation, education opportunities, and
technology transfer. Some certification programs have tools and research products to help quantify these benefits.
Limitations
The
ongoing use of offsets and credits faces a variety of criticisms. Some
argue that they promote a "business-as-usual" mindset, where companies
are able to use carbon offsetting as a way to avoid making larger
changes that deal with reducing carbon emissions at its source. These projects are also seen as "Greenwashing".
In 2023 a civil suit was brought against Delta Airlines based on its
use of carbon credits to support claims of carbon neutrality.
In 2016 the Öko-Institut found that 85% of CDM projects analyzed had a
low likelihood of being truly additional and without over-estimated
emission reductions.
An additional challenge is that offsets and credits are being marketed
in a global environment where carbon pricing and existing policies are
still inadequate to meet Paris goals. However, there is evidence that companies that invest in offsets and
credits tend to make more ambitious emissions cuts compared with
companies that do not.
Oversight issues
Several certification standards exist, offering variations for measuring emissions baseline, reductions, additionality,
and other key criteria. However, no single standard governs the
industry, and some offset providers have been criticized on the grounds
that carbon reduction claims are exaggerated or misleading. For example carbon credits issued by the California Air Resources Board
were found to use a formula that established fixed boundaries around
forest regions, creating simplified, regional averages for the carbon
stored in a wide mix of tree species. As a result it is estimated that
California's cap and trade program program has generated between
20 million and 39 million forestry credits that do not achieve real
climate benefits. This amounts to nearly one in three credits issued
through that program.
Additionality determinations can be difficult, and may present risks for buyers of offsets or credits.
Carbon projects that yield strong financial returns even in the absence
of revenue from carbon credits; or that are compelled by regulations;
or that represent common practice in an industry; are usually not
considered additional. A full determination of additionality requires a
careful investigation of proposed carbon offset projects.
Because offsets provide a revenue stream for the reduction of
some types of emissions, they can in some cases provide incentives to
emit more, so that emitting entities can later get credit for reducing
emissions from an artificially high baseline. Actions by regulatory
agencies could address these situations. These could include specific
standards for verifiability, uniqueness, and transparency.
Concerns with forestry projects
Forestry
projects have been increasingly criticized in terms of their integrity
as offset or credit programs. A number of news stories in 2021–2023 have
criticized nature based carbon offsets, the REDD+ program, and
certification organizations. In one case it was estimated that ~90% of rainforest offset credits of the Verified Carbon Standard are likely to be "phantom credits".
Tree planting projects in particular have been problematic.
Critics point to a number of concerns. Trees reach maturity over a
course of many decades. It is difficult to guarantee the permanence of
the forests, which may be susceptible to clearing, burning, or
mismanagement.
Some tree-planting projects introduce fast-growing invasive species
that end up damaging native forests and reducing biodiversity.
In response, some certification standards, such as the Climate
Community and Biodiversity Standard require multiple species plantings.
Tree planting in high latitude forests may have a net warming effect on
the Earth's climate. This is because the absorption of sunlight by tree
cover creates a warming effect that balances out their absorption of
carbon dioxide.
Tree-planting projects can also cause conflicts with local communities
and indigenous people who are displaced or otherwise find their use of
forest resources curtailed.
Since about 2001 the term nuclear renaissance has been used to refer to a possible nuclear power industry revival, but nuclear electricity generation in 2012 was at its lowest level since 1999.
Since then it had increased back to 2,653 TWh in 2021, a level last
seen in 2006. The share of nuclear power in electricity production
however is at a historic low and now below 10% down from a maximum of
17.5% in 1996.
Following the March 2011 Fukushima I nuclear accidents,
China, Germany, Switzerland, Israel, Malaysia, Thailand, United
Kingdom, and the Philippines are reviewing their nuclear power programs.
Indonesia and Vietnam still plan to build nuclear power plants.Thirty-one countries operate nuclear power stations, and there are a considerable number of new reactors being built in China, South Korea, India, and Russia. As of June 2011, countries such as Australia, Austria, Denmark, Greece, Ireland, Latvia, Lichtenstein, Luxembourg, Malta, Portugal, Israel, Malaysia, and Norway have no nuclear power stations and remain opposed to nuclear power.
Since nuclear energy and nuclear weapons technologies are closely related, military aspirations can act as a factor in energy policy decisions. The fear of nuclear proliferation influences some international nuclear energy policies.
In 2004, the largest producer of nuclear energy was the United States with 28% of worldwide capacity, followed by France (18%) and Japan (12%). In 2007, 31 countries operated nuclear power plants.
In September 2008 the IAEA projected nuclear power to remain at a 12.4%
to 14.4% share of the world's electricity production through 2030.
In 2013, almost two years after Fukushima, according to the IAEA
there are 390 operating nuclear generating units throughout the world,
more than 10% less than before Fukushima, and exactly the same as in
Chernobyl-year 1986.
Asia is expected to be the primary growth market for nuclear energy in
the foreseeable future, despite continued uncertainty in the energy
outlooks for Japan, South Korea, and others in the region. As of 2014,
63% of all reactors under construction globally are in Asia.
For some countries, nuclear power affords energy independence. In the words of the French, "We have no coal, we have no oil, we have no gas, we have no choice." Japan—similarly lacking in indigenous natural resources for power supply—relied on nuclear power for 1/3 of its energy mix
prior to the Fukushima nuclear disaster; since March 2011, Japan has
sought to offset the loss of nuclear power with increased reliance on
imported liquefied natural gas, which has led to the country's first trade deficits in decades. Therefore, the discussion of a future for nuclear energy is intertwined with a discussion of energy security and the use of energy mix, including renewable energy development.
Nuclear power has been relatively unaffected by embargoes, and uranium is mined in "reliable" countries, including Australia and Canada.
Many commentators have criticized Germany's Energiewende policy
to shut down its world-class nuclear fleet after the Fukushima disaster
and rely instead on renewable energy sources, which in the interim has
made them heavily dependent on Russian gas.
Responding to Russia's attempt to exploit this dependency by shutting
off natural gas supplies, Germany is ramping up coal production, while maintaining two nuclear plants in reserve.
Nuclear energy history and trends
Proponents have long made hopeful projections of the expected growth
of nuclear power, but major accidents, and a well funded anti-nuclear
lobby have kept costs high and growth much lower. In 1973 and 1974, the
International Atomic Energy Agency
predicted a worldwide installed nuclear capacity of 3,600 to 5,000
gigawatts by 2000. The IAEA's 1980 projection was for 740 to 1,075
gigawatts of installed capacity by the year 2000. Even after the 1986 Chernobyl disaster, the Nuclear Energy Agency
forecasted an installed nuclear capacity of 497 to 646 gigawatts for
the year 2000. The actual capacity in 2000 was 356 gigawatts.
Moreover, construction costs have often been much higher, and times much
longer than projected, failing to meet optimistic projections of
“unlimited cheap, clean, and safe electricity.”
Since about 2001 the term nuclear renaissance has been used to refer to a possible nuclear power industry revival, driven by rising fossil fuel prices and new concerns about meeting greenhouse gas emission limits. However, nuclear electricity generation in 2012 was at its lowest level since 1999, and new reactors under construction in Finland and France, which were meant to lead a nuclear renaissance, have been delayed and are running over-budget. China has 32 new reactors under construction,
and there are also a considerable number of new reactors being built in
South Korea, India, and Russia. At the same time, at least 100 older
and smaller reactors will "most probably be closed over the next 10-15
years". So the expanding nuclear programs in Asia are balanced by retirements of aging plants and nuclear reactor phase-outs.
In March 2011 the nuclear emergencies at Japan's Fukushima I Nuclear Power Plant and shutdowns at other nuclear facilities raised questions among some commentators over the future of the renaissance. Platts
has reported that "the crisis at Japan's Fukushima nuclear plants has
prompted leading energy-consuming countries to review the safety of
their existing reactors and cast doubt on the speed and scale of planned
expansions around the world". China, Germany, Switzerland, Israel, Malaysia, Thailand, United Kingdom, Italy and the Philippines have reviewed their nuclear power programs. Indonesia and Vietnam still plan to build nuclear power plants. Countries such as Australia, Austria, Denmark, Greece, Ireland, Latvia, Liechtenstein, Luxembourg, Portugal, Israel, Malaysia, New Zealand, and Norway remain opposed to nuclear power. Following the Fukushima I nuclear accidents, the International Energy Agency halved its estimate of additional nuclear generating capacity built by 2035.
Following the Fukushima nuclear disaster, Germany permanently shut down eight of its reactors and pledged to close the rest by 2022. In 2011 Siemens exited the nuclear power sector following the changes to German energy policy, and supported the German government's planned energy transition to renewable energy technologies. The Italians voted overwhelmingly to keep their country non-nuclear. Switzerland and Spain have banned the construction of new reactors. Japan's prime minister called for a dramatic reduction in Japan's reliance on nuclear power.
Taiwan's president did the same. Mexico has sidelined construction of
10 reactors in favor of developing natural-gas-fired plants. Belgium decided to phase out its nuclear plants.
China—nuclear power's largest prospective market—suspended
approvals of new reactor construction while conducting a lengthy
nuclear-safety review. In 2012 a new safety plan for nuclear power was approved by State
Council, and full incorporation of International Atomic Energy Agency
(IAEA) safety standards became explicit. In the 13th Five-Year Plan from
2016, six to eight nuclear reactors were to be approved each year. A
draft of the 14th Five-Year Plan (2021-2025) released in March 2021
showed government plans to reach 70 GWe gross of nuclear capacity by the
end of 2025.
Neighboring India, another potential nuclear boom market, has
encountered effective local opposition, growing national wariness about
foreign nuclear reactors, and a nuclear liability controversy that
threatens to prevent new reactor imports. There have been mass protests
against the French-backed 9900 MW Jaitapur Nuclear Power Project in Maharashtra and the 2000 MW Koodankulam Nuclear Power Plant
in Tamil Nadu. The state government of West Bengal state has also
refused permission to a proposed 6000 MW facility near the town of
Haripur that intended to host six Russian reactors.
In March 2018, the government stated that nuclear capacity would fall
well short of its 63 GWe target and that the total nuclear capacity is
likely to be about 22.5 GWe by the year 2031.
Following IPCC announcements climate concerns again started to
dominate world opinion. With rising oil and gas prices in 2022, many
countries are reconsidering nuclear power.
In October 2021 the Japanese cabinet approved the new Plan for
Electricity Generation to 2030 prepared by the Agency for Natural
Resources and Energy (ANRE) and an advisory committee, following public
consultation. The nuclear target for 2030 of 20-22% is unchanged from
that in the 2015 plan, but renewables increase greatly to 36-38%,
including geothermal and hydro. Hydrogen and ammonia are included at 1%.
The plan would require the restart of another ten reactors. Prime
minister Fumio Kishida
in July 2022 announced that the country should consider building
advanced reactors and extending operating licences beyond 60 years.
In March 2022 Belgium delayed its plans to phase out nuclear
energy by a decade. The prime minister said that two reactors (Doel 4
and Tihange 3) would continue operating to 2035 to “strengthen our
county’s independence from fossil fuels in a turbulent geopolitical
environment.” In June Engie said it was seeking financial aid from the
government for the continued operation of the two reactors.
Climate Change and the Energy Transition
Eliminating fossil fuels is essential in solving the climate change crisis. Nuclear power has one of the lowest life-cycle greenhouse gas emissions.
Historically, nuclear power has prevented 64 gigatonnes of CO2-equivalent greenhouse-gas emissions between 1971 and 2009.
With a significant amount of renewable energy installed in the 21st
century, it has been speculated that tensions between nuclear and
renewable national energy development strategies might reduce their
effectiveness in terms of climate change mitigation.
However, newer studies have refuted this idea. Both nuclear and
renewable energy have shown equally effective in the prevention of
greenhouse-gas emissions. An effective climate-change mitigation strategy may include both nuclear and renewable energy sources.
In 2018 the IPCC provided advice to policymakers giving four
illustrative model pathways to limit warming to 1.5 degrees. In each of
these pathways nuclear energy generation increased between 98% and 501%
over 2010 levels by 2050.
In 2021 the European Union Joint Research Centre issued the
results of its study on whether nuclear power generation meets the
criteria of its Green Taxonomy. The analyses did not reveal any
science-based evidence that nuclear energy does more harm to human
health or to the environment than other electricity production
technologies already included in the EU Green Taxonomy as activities
supporting climate change mitigation. As a result of this assessment, the EU Parliament voted to include nuclear energy in its Green Taxonomy.
Moreover, nuclear energy has such a low carbon footprint that it could power carbon dioxide capture and transformation, resulting in a carbon-negative process. Specifically, various organizations are working across the globe to create designs for small modular reactors, a type of nuclear fission reactor that is smaller than conventional reactors. Some of these companies include ARC Nuclear in Canada, CNEA in Denmark, Areva TA in France, Toshiba and JAERI in Japan, OKB Gidropress in Russia, and OPEN100 and X-energy in the United States.