Applications of 3D printing

From Wikipedia, the free encyclopedia

3D printing has many applications. In manufacturing, medicine, architecture, and custom art and design. Some people use 3D printers to create more 3D printers. In the current scenario, 3D printing process has been used in manufacturing, medical, industry and sociocultural sectors which facilitate 3D printing to become successful commercial technology.

Manufacturing applications

Three-dimensional printing makes it as cheap to create single items as it is to produce thousands and thus undermines economies of scale. It may have as profound an impact on the world as the coming of the factory did....Just as nobody could have predicted the impact of the steam engine in 1750—or the printing press in 1450, or the transistor in 1950—it is impossible to foresee the long-term impact of 3D printing. But the technology is coming, and it is likely to disrupt every field it touches.

— The Economist, in a February 10, 2011 leader^[2]

AM technologies found applications starting in the 1980s in product development, data visualization, rapid prototyping, and specialized manufacturing. Their expansion into production (job production, mass production, and distributed manufacturing) has been under development in the decades since. Industrial production roles within the metalworking industries^[3] achieved significant scale for the first time in the early 2010s. Since the start of the 21st century there has been a large growth in the sales of AM machines, and their price has dropped substantially.^[4] According to Wohlers Associates, a consultancy, the market for 3D printers and services was worth $2.2 billion worldwide in 2012, up 29% from 2011.^[5] McKinsey predicts that additive manufacturing could have an economic impact of $550 billion annually by 2025.^[6] There are many applications for AM technologies, including architecture, construction (AEC), industrial design, automotive, aerospace,^[7] military, engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, education, geographic information systems, food, and many other fields.

Additive manufacturing's earliest applications have been on the toolroom end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission was to reduce the lead time and cost of developing prototypes of new parts and devices, which was earlier only done with subtractive toolroom methods such as cnc milling and turning, and precision grinding, far more accurate than 3d printing with accuracy down to 0.00005" and creating better quality parts faster, but sometimes too expensive for low accuracy prototype parts.^[8] With technological advances in additive manufacturing, however, and the dissemination of those advances into the business world, additive methods are moving ever further into the production end of manufacturing in creative and sometimes unexpected ways.^[8] Parts that were formerly the sole province of subtractive methods can now in some cases be made more profitably via additive ones. In addition, new developments in RepRap technology allow the same device to perform both additive and subtractive manufacturing by swapping magnetic-mounted tool heads.^[9]

Cloud-based additive manufacturing

Additive manufacturing in combination with cloud computing technologies allows decentralized and geographically independent distributed production.^[10] Cloud-based additive manufacturing refers to a service-oriented networked manufacturing model in which service consumers are able to build parts through Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), Hardware-as-a-Service (HaaS), and Software-as-a-Service (SaaS).^[11][12][13] Distributed manufacturing as such is carried out by some enterprises; there is also a services like 3D Hubs that put people needing 3D printing in contact with owners of printers.^[14]

Some companies offer on-line 3D printing services to both commercial and private customers,^[15] working from 3D designs uploaded to the company website. 3D-printed designs are either shipped to the customer or picked up from the service provider.^[16]

Mass customization

Miniature face models (from FaceGen) produced using Ceramic Based material on a Full Colour 3D Inkjet Printer

Companies have created services where consumers can customize objects using simplified web based customization software, and order the resulting items as 3D printed unique objects.^[17][18] This now allows consumers to create custom cases for their mobile phones.^[19] Nokia has released the 3D designs for its case so that owners can customize their own case and have it 3D printed.^[20]

Rapid manufacturing

Advances in RP technology have introduced materials that are appropriate for final manufacture, which has in turn introduced the possibility of directly manufacturing finished components. One advantage of 3D printing for rapid manufacturing lies in the relatively inexpensive production of small numbers of parts.

Rapid manufacturing is a new method of manufacturing and many of its processes remain unproven. 3D printing is now entering the field of rapid manufacturing and was identified as a "next level" technology by many experts in a 2009 report.^[21] One of the most promising processes looks to be the adaptation of selective laser sintering (SLS), or direct metal laser sintering (DMLS) some of the better-established rapid prototyping methods. As of 2006, however, these techniques were still very much in their infancy, with many obstacles to be overcome before RM could be considered a realistic manufacturing method.^[22]

Rapid prototyping

Industrial 3D printers have existed since the early 1980s and have been used extensively for rapid prototyping and research purposes. These are generally larger machines that use proprietary powdered metals, casting media (e.g. sand), plastics, paper or cartridges, and are used for rapid prototyping by universities and commercial companies.

Research

3D printing can be particularly useful in research labs due to its ability to make specialized, bespoke geometries. In 2012 a proof of principle project at the University of Glasgow, UK, showed that it is possible to use 3D printing techniques to assist in the production of chemical compounds. They first printed chemical reaction vessels, then used the printer to deposit reactants into them.^[23] They have produced new compounds to verify the validity of the process, but have not pursued anything with a particular application.

Usually, the FDM process is used to print hollow reaction vessels or microreactors.^[23] If the 3D print is performed within an inert gas atmosphere, the reaction vessels can be filled with highly reactive substances during the print. The 3D printed objects are air- and watertight for several weeks. By the print of reaction vessels in the geometry of common cuvettes or measurement tubes, routine analytical measurements such as UV/VIS-, IR- and NMR-spectroscopy can be performed directly in the 3D printed vessel.^[24]

In addition, 3D printing has been used in research labs as alternative method to manufacture components for use in experiments, such as magnetic shielding and vacuum components with demonstrated performance comparable to traditionally produced parts.^[25]

Food

Additive manufacturing of food is being developed by squeezing out food, layer by layer, into three-dimensional objects. A large variety of foods are appropriate candidates, such as chocolate and candy, and flat foods such as crackers, pasta,^[26] and pizza.^[27][28] NASA has considered the versatility of the concept, awarding a contract to the Systems and Materials Research Consultancy to study the feasibility of printing food in space.^[29] One of the problems with food printing is the nature of the texture of a food. For example, foods that are not strong enough to be filed are not appropriate for 3D printing.

Agile tooling

Agile tooling is the process of using modular means to design tooling that is produced by additive manufacturing or 3D printing methods to enable quick prototyping and responses to tooling and fixture needs. Agile tooling uses a cost effective and high quality method to quickly respond to customer and market needs. It can be used in hydro-forming, stamping, injection molding and other manufacturing processes.

Medical applications

Surgical uses of 3D printing-centric therapies have a history beginning in the mid-1990s with anatomical modeling for bony reconstructive surgery planning.^[30] By practicing on a tactile model before surgery, surgeons were more prepared and patients received better care. Patient-matched implants were a natural extension of this work, leading to truly personalized implants that fit one unique individual.^[31] Virtual planning of surgery and guidance using 3D printed, personalized instruments have been applied to many areas of surgery including total joint replacement and craniomaxillofacial reconstruction with great success.^{[clarification needed][32]} Further study of the use of models for planning heart and solid organ surgery has led to increased use in these areas.^[33] Hospital-based 3D printing is now of great interest and many institutions are pursuing adding this specialty within individual radiology departments.^[34][35] The technology is being used to create unique, patient-matched devices for rare illnesses. One example of this is the bioresorbable trachial splint to treat newborns with tracheobronchomalacia^[36] developed at the University of Michigan. Several devices manufacturers have also begin using 3D printing for patient-matched surgical guides (polymers). The use of additive manufacturing for serialized production of orthopedic implants (metals) is also increasing due to the ability to efficiently create porous surface structures that facilitate osseointegration. Printed casts for broken bones can be custom-fitted and open, letting the wearer scratch any itches, wash and ventilate the damaged area. They can also be recycled.

Fused filament fabrication (FFF) has been used to create microstructures with a three-dimensional internal geometry. Sacrificial structures or additional support materials are not needed. Structure using polylactic acid (PLA) can have fully controllable porosity in the range 20%–60%. Such scaffolds could serve as biomedical templates for cell culturing, or biodegradable implants for tissue engineering.^[37]

3D printed human skull from computed computer tomography data

3D printing has been used to print patient specific implant and device for medical use. Successful operations include a titanium pelvis implanted into a British patient, titanium lower jaw transplanted to a Dutch patient,^[38] and a plastic tracheal splint for an American infant.^[39] The hearing aid and dental industries are expected to be the biggest area of future development using the custom 3D printing technology.^[40] In March 2014, surgeons in Swansea used 3D printed parts to rebuild the face of a motorcyclist who had been seriously injured in a road accident.^[41] Research is also being conducted on methods to bio-print replacements for lost tissue due to arthritis and cancer.

3D printing technology can now be used to make exact replicas of organs. The printer uses images from patients' MRI or CT scan images as a template and lays down layers of rubber or plastic.

Bio-printing

In 2006, researchers at Cornell University published some of the pioneer work in 3D printing for tissue fabrication, successfully printing hydrogel bio-inks.^[42] The work at Cornell was expanded using specialized bioprinters produced by Seraph Robotics, Inc., a university spin-out, which helped to catalyze a global interest in biomedical 3D printing research.

3D printing has been considered as a method of implanting stem cells capable of generating new tissues and organs in living humans.^[43] With their ability to transform into any other kind of cell in the human body, stem cells offer huge potential in 3D bio-printing.^[44] Professor Leroy Cronin of Glasgow University proposed in a 2012 TED Talk that it was possible to use chemical inks to print medicine.^[45]

As of 2012, 3D bio-printing technology has been studied by biotechnology firms and academia for possible use in tissue engineering applications in which organs and body parts are built using inkjet techniques. In this process, layers of living cells are deposited onto a gel medium or sugar matrix and slowly built up to form three-dimensional structures including vascular systems.^[46] The first production system for 3D tissue printing was delivered in 2009, based on NovoGen bioprinting technology.^[47] Several terms have been used to refer to this field of research: organ printing, bio-printing, body part printing,^[48] and computer-aided tissue engineering, among others.^[49] The possibility of using 3D tissue printing to create soft tissue architectures for reconstructive surgery is also being explored.^[50]

In 2013, Chinese scientists began printing ears, livers and kidneys, with living tissue. Researchers in China have been able to successfully print human organs using specialized 3D bio printers that use living cells instead of plastic. Researchers at Hangzhou Dianzi University designed the "3D bio printer" dubbed the "Regenovo". Xu Mingen, Regenovo's developer, said that it can produce a miniature sample of liver tissue or ear cartilage in less than an hour, predicting that fully functional printed organs might take 10 to 20 years to develop.^[51][52]

Medical devices

On October 24, 2014, a five-year-old girl born without fully formed fingers on her left hand became the first child in the UK to have a prosthetic hand made with 3D printing technology. Her hand was designed by US-based E-nable, an open source design organisation which uses a network of volunteers to design and make prosthetics mainly for children. The prosthetic hand was based on a plaster cast made by her parents.^[53] A boy named Alex was also born with a missing arm from just above the elbow. The team was able to use 3D printing to upload an e-NABLE Myoelectric arm that runs off of servos and batteries that are actuated by the electromyography muscle. With the use of 3D printers, E-NABLE has so far distributed more than 400 plastic hands to children.

Printed prosthetics have been used in rehabilitation of crippled animals. In 2013, a 3D printed foot let a crippled duckling walk again.^[54] In 2014 a chihuahua born without front legs was fitted with a harness and wheels created with a 3D printer.^[55] 3D printed hermit crab shells let hermit crabs inhabit a new style home.^[56] A prosthetic beak was another tool developed by the use of 3D printing to help aid a bald eagle named Beauty, whose beak was severely mutilated from a shot in the face. Since 2014, commercially available titanium knee implants made with 3D printer for dogs have been used to restore the animals' mobility. Over 10,000 dogs in Europe and United States have been treated after only one year.^[57]

In February 2015, FDA approved the marketing of a surgical bolt which facilitates less-invasive foot surgery and eliminates the need to drill through bone. The 3D printed titanium device, 'FastForward Bone Tether Plate' is approved to use in correction surgery to treat bunion.^[58] In October 2015, the group of Professor Andreas Herrmann at the University of Groningen has developed the first 3D printable resins with antimicrobial properties. Employing stereolithography, quaternary ammonium groups are incorporated into dental appliances that kill bacteria on contact. This type of material can be further applied in medical devices and implants.^[59]

On June 6, 2011, the company Xilloc Medical together with researchers at the University of Hasselt, in Belgium had successfully printed a new jawbone for an 83-year-old Dutch woman from the province of Limburg.^[60]

3D printing has been used to produce prosthetic beaks for eagles, a Brazilian goose named Victoria, and a Costa Rican toucan called Grecia.^[61]

Pills

The first pill manufactured by 3D printing was approved by the FDA in August 2015. Binder-jetting into a powder bed of the drug allows very porous pills to be produced, which enables high drug doses in a single pill which dissolves quickly and can be ingested easily.^[62] This has been demonstrated for Spritam, a reformulation of levetiracetam for the treatment of epilepsy.^[63]

Industrial applications

Apparel

inBloom 3D printed outfit

3D printing has entered the world of clothing with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses.^[64] In commercial production Nike is using 3D printing to prototype and manufacture the 2012 Vapor Laser Talon football shoe for players of American football, and New Balance is 3D manufacturing custom-fit shoes for athletes.^[64][65]

3D printing has come to the point where companies are printing consumer grade eyewear with on-demand custom fit and styling (although they cannot print the lenses). On-demand customization of glasses is possible with rapid prototyping.^[66]

However, comment has been made in academic circles as to the potential limitation of the human acceptance of such mass customised apparel items due to the potential reduction of brand value communication.^[67]

In the world of high fashion courtiers such as Karl Lagerfeld designing for Chanel, Iris van Herpen and Noa Raviv working with technology from Stratasys, have employed and featured 3d printing in their collections. Selections from theie lines and other working with 3d printing were showcased at the 2016 Metropolitan Museum of Art Anna Wintour Costume Center, exhibition "Manus X Machina".

Industrial art and jewelry

3D printing is used to manufacture moulds for making jewelery, and even the jewelery itself.^[72] 3D printing is becoming popular in the customisable gifts industry, with products such as personalized models of art and dolls,^[73] in many shapes: in metal or plastic, or as consumable art, such as 3D printed chocolate.^[74]

Automotive industry

The Audi RSQ was made with rapid prototyping industrial KUKA robots.

In early 2014, Swedish supercar manufacturer Koenigsegg announced the One:1, a supercar that utilizes many components that were 3D printed. In the limited run of vehicles Koenigsegg produces, the One:1 has side-mirror internals, air ducts, titanium exhaust components, and complete turbocharger assemblies that were 3D printed as part of the manufacturing process.^[75]

Urbee is the name of the first car in the world car mounted using the technology 3D printing (its bodywork and car windows were "printed"). Created in 2010 through the partnership between the US engineering group Kor Ecologic and the company Stratasys (manufacturer of printers Stratasys 3D), it is a hybrid vehicle with futuristic look.^[76][77][78]

In 2014, Local Motors debuted Strati, a functioning vehicle that was entirely 3D Printed using ABS plastic and carbon fiber, except the powertrain.^[79] In 2015, the company produced another iteration known as the LM3D Swim that was 80 percent 3D-printed.^[80] In 2016, the company has used 3D printing in the creation of automotive parts, such ones used in Olli, a self-driving vehicle developed by the company.^[81][82]

In May 2015 Airbus announced that its new Airbus A350 XWB included over 1000 components manufactured by 3D printing.^[83]

3D printing is also being utilized by air forces to print spare parts for planes. In 2015, a Royal Air Force Eurofighter Typhoon fighter jet flew with printed parts. The United States Air Force has begun to work with 3D printers, and the Israeli Air Force has also purchased a 3D printer to print spare parts.^[84]

Construction

The use of 3D printing to produce scale models within architecture and construction has steadily increased in popularity as the cost of 3D printers has reduced. This has enabled faster turn around of such scale models and allowed a steady increase in the speed of production and the complexity of the objects being produced.

Construction 3D printing, the application of 3D printing to fabricate construction components or entire buildings has been in development since the mid 1990s, development of new technologies has steadily gained pace since 2012 and the sub-sector of 3D printing is beginning to mature. See main article.

Firearms

In 2012, the US-based group Defense Distributed disclosed plans to "[design] a working plastic gun that could be downloaded and reproduced by anybody with a 3D printer."^[85][86] Defense Distributed has also designed a 3D printable AR-15 type rifle lower receiver (capable of lasting more than 650 rounds) and a 30-round M16 magazine. The AR-15 has multiple receivers (both an upper and lower receiver), but the legally controlled part is the one that is serialized (the lower, in the AR-15's case). Soon after Defense Distributed succeeded in designing the first working blueprint to produce a plastic gun with a 3D printer in May 2013, the United States Department of State demanded that they remove the instructions from their website.^[87] After Defense Distributed released their plans, questions were raised regarding the effects that 3D printing and widespread consumer-level CNC machining^[88][89] may have on gun control effectiveness.

In 2014, a man from Japan became the first person in the world to be imprisoned for making 3D printed firearms.^[94] Yoshitomo Imura posted videos and blueprints of the gun online and was sentenced to jail for two years. Police found at least two guns in his household that were capable of firing bullets.^[94]

Computers and robots

3D printing can also be used to make laptops and other computers and cases. For example, Novena and VIA OpenBook standard laptop cases. I.e. a Novena motherboard can be bought and be used in a printed VIA OpenBook case.^[95]

Open-source robots are built using 3D printers. Double Robotics grant access to their technology (an open SDK).^[96][97][98] On the other hand, 3&DBot is an Arduino 3D printer-robot with wheels^[99] and ODOI is a 3D printed humanoid robot.^[100]

Soft sensors and actuators

3D printing has found its place in soft sensors and actuators manufacturing inspired by 4D printing concept.^{[101][102][103]} The majority of the conventional soft sensors and actuators are fabricated using multistep low yield processes entailing manual fabrication, post-processing/assembly, and lengthy iterations with less flexibility in customization and reproducibility of final products. 3D printing has been a game changer in these fields with introducing the custom geometrical, functional, and control properties to avoid the tedious and time-consuming aspects of the earlier fabrication processes.^[104]

Space

The Zero-G Printer, the first 3D printer designed to operate in zero gravity, was built under a joint partnership between NASA Marshall Space Flight Center (MSFC) and Made In Space, Inc.^[105] In September 2014, SpaceX delivered the zero-gravity 3D printer to the International Space Station (ISS). On December 19, 2014, NASA emailed CAD drawings for a socket wrench to astronauts aboard the ISS, who then printed the tool using its 3D printer. Applications for space offer the ability to print parts or tools on-site, as opposed to using rockets to bring along pre-manufactured items for space missions to human colonies on the moon, Mars, or elsewhere.^[106] The second 3D printer in space, the European Space Agency's Portable On-Board 3D Printer (POP3D) was planned to be delivered to the International Space Station before June 2015.^[107][108] In 2016, Digital Trends reported that BeeHex was building a 3D food printer for manned missions to Mars.^[109]

Most construction planned on asteroids or planets will be bootstrapped somehow using the materials available on those objects. 3D printing is often one of the steps in this bootstrapping. The Sinterhab project is researching a lunar base constructed by 3D printing using lunar regolith as a base material. Instead of adding a binding agent to the regolith, researchers are experimenting with microwave sintering to create solid blocks from the raw material.^[110]

Projects like these have been investigated for construction of off-Earth habitats.^[111][112]

Sociocultural applications

An example of 3D printed limited edition jewellery. This necklace is made of glassfiber-filled dyed nylon. It has rotating linkages that were produced in the same manufacturing step as the other parts

In 2005, a rapidly expanding hobbyist and home-use market was established with the inauguration of the open-source RepRap and Fab@Home projects. Virtually all home-use 3D printers released to-date have their technical roots in the ongoing RepRap Project and associated open-source software initiatives.^[113] In distributed manufacturing, one study has found^[114] that 3D printing could become a mass market product enabling consumers to save money associated with purchasing common household objects.^[115] For example, instead of going to a store to buy an object made in a factory by injection molding (such as a measuring cup or a funnel), a person might instead print it at home from a downloaded 3D model.

Art and jewelry

In 2005, academic journals began to report on the possible artistic applications of 3D printing technology,^[116] being used by artists such as Martin John Callanan at The Bartlett school of architecture. By 2007 the mass media followed with an article in the Wall Street Journal^[117] and Time Magazine, listing a printed design among their 100 most influential designs of the year.^[118] During the 2011 London Design Festival, an installation, curated by Murray Moss and focused on 3D Printing, was held in the Victoria and Albert Museum (the V&A). The installation was called Industrial Revolution 2.0: How the Material World will Newly Materialize.^[119]

At the 3DPrintshow in London, which took place in November 2013 and 2014, the art sections had works made with 3D printed plastic and metal. Several artists such as Joshua Harker, Davide Prete, Sophie Kahn, Helena Lukasova, Foteini Setaki showed how 3D printing can modify aesthetic and art processes.^[120] In 2015, engineers and designers at MIT's Mediated Matter Group and Glass Lab created an additive 3D printer that prints with glass, called G3DP. The results can be structural as well as artistic. Transparent glass vessels printed on it are part of some museum collections.^[121]

The use of 3D scanning technologies allows the replication of real objects without the use of moulding techniques that in many cases can be more expensive, more difficult, or too invasive to be performed, particularly for precious artwork or delicate cultural heritage artifacts^[122] where direct contact with the moulding substances could harm the original object's surface.

3D selfies

A 3D selfie in 1:20 scale printed by Shapeways using gypsum-based printing

Fantasitron 3D photo booth at Madurodam

A 3D photo booth such as the Fantasitron located at Madurodam, the miniature park, generates 3D selfie models from 2D pictures of customers. These selfies are often printed by dedicated 3D printing companies such as Shapeways. These models are also known as 3D portraits, 3D figurines or mini-me figurines.

Communication

Employing additive layer technology offered by 3D printing, Terahertz devices which act as waveguides, couplers and bends have been created. The complex shape of these devices could not be achieved using conventional fabrication techniques. Commercially available professional grade printer EDEN 260V was used to create structures with minimum feature size of 100 µm. The printed structures were later DC sputter coated with gold (or any other metal) to create a Terahertz Plasmonic Device.^[123] In 2016 artist/scientist Janine Carr Created the first 3d printed vocal percussion (beatbox) as a waveform, with the ability to play the soundwave by laser, along with four vocalised emotions these were also playable by laser.^[124]

Domestic use

Some early consumer examples of 3d printing include the 64DD released in 1999 in Japan.^[125][126] As of 2012, domestic 3D printing was mainly practiced by hobbyists and enthusiasts. However, little was used for practical household applications, for example, ornamental objects. Some practical examples include a working clock^[127] and gears printed for home woodworking machines among other purposes.^[128] Web sites associated with home 3D printing tended to include backscratchers, coat hooks, door knobs, etc.^[129]

The open source Fab@Home project^[130] has developed printers for general use. They have been used in research environments to produce chemical compounds with 3D printing technology, including new ones, initially without immediate application as proof of principle.^[23] The printer can print with anything that can be dispensed from a syringe as liquid or paste. The developers of the chemical application envisage both industrial and domestic use for this technology, including enabling users in remote locations to be able to produce their own medicine or household chemicals.

3D printing is now working its way into households, and more and more children are being introduced to the concept of 3D printing at earlier ages. The prospects of 3D printing are growing, and as more people have access to this new innovation, new uses in households will emerge.^[133]

The OpenReflex SLR film camera was developed for 3D printing as an open-source student project.^[134]

Education and research

High School students from Wyomissing Area Jr/Sr High School in Pennsylvania, United States present their use of 3D Printing in the classroom

3D printing, and open source 3D printers in particular, are the latest technology making inroads into the classroom. 3D printing allows students to create prototypes of items without the use of expensive tooling required in subtractive methods. Students design and produce actual models they can hold. The classroom environment allows students to learn and employ new applications for 3D printing.^[138] RepRaps, for example, have already been used for an educational mobile robotics platform.^[139]

Some authors have claimed that 3D printers offer an unprecedented "revolution" in STEM education.^[140] The evidence for such claims comes from both the low cost ability for rapid prototyping in the classroom by students, but also the fabrication of low-cost high-quality scientific equipment from open hardware designs forming open-source labs.^[141] Engineering and design principles are explored as well as architectural planning. Students recreate duplicates of museum items such as fossils and historical artifacts for study in the classroom without possibly damaging sensitive collections. Other students interested in graphic designing can construct models with complex working parts easily. 3D printing gives students a new perspective with topographic maps. Science students can study cross-sections of internal organs of the human body and other biological specimens. And chemistry students can explore 3D models of molecules and the relationship within chemical compounds.^[142]

According to a recent paper by Kostakis et al.,^[143] 3D printing and design can electrify various literacies and creative capacities of children in accordance with the spirit of the interconnected, information-based world.

Future applications for 3D printing might include creating open-source scientific equipment.^[141][144]

Environmental use

In Bahrain, large-scale 3D printing using a sandstone-like material has been used to create unique coral-shaped structures, which encourage coral polyps to colonize and regenerate damaged reefs. These structures have a much more natural shape than other structures used to create artificial reefs, and, unlike concrete, are neither acid nor alkaline with neutral pH.^[145]

Cultural heritage

3D printed sculpture of the Egyptian Pharaoh Merankhre Mentuhotep shown at Threeding

In the last several years 3D printing has been intensively used by in the cultural heritage field for preservation, restoration and dissemination purposes.^[146] Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics.^[147]

Scan the World is the largest archive of 3D printable objects of cultural significance from across the globe. Each object, originating from 3D scan data provided by their community, is optimised for 3D printing and free to download on MyMiniFactory. Through working alongside museums, such as The Victoria and Albert Museum^[148] and private collectors,^[149] the initiative serves as a platform for democratizing the art object.

The Metropolitan Museum of Art and the British Museum have started using their 3D printers to create museum souvenirs that are available in the museum shops.^[150] Other museums, like the National Museum of Military History and Varna Historical Museum, have gone further and sell through the online platform Threeding digital models of their artifacts, created using Artec 3D scanners, in 3D printing friendly file format, which everyone can 3D print at home.^[151]

Specialty materials

Consumer grade 3D printing has resulted in new materials that have been developed specifically for 3D printers. For example, filament materials have been developed to imitate wood in its appearance as well as its texture. Furthermore, new technologies, such as infusing carbon fiber^[152] into printable plastics, allowing for a stronger, lighter material. In addition to new structural materials that have been developed due to 3D printing, new technologies have allowed for patterns to be applied directly to 3D printed parts. Iron oxide-free Portland cement powder has been used to create architectural structures up to 9 feet in height.

Green Revolution

From Wikipedia, the free encyclopedia

After the Second World War, increased deployment of technologies including pesticides, herbicides, and fertilizers as well as new breeds of high yield crops greatly increased global food production.

The Green Revolution, or Third Agricultural Revolution, refers to a set of research and the development of technology transfer initiatives occurring between the 1930s and the late 1960s (with prequels in the work of the agrarian geneticist Nazareno Strampelli in the 1920s and 1930s), that increased agricultural production worldwide, particularly in the developing world, beginning most markedly in the late 1960s. The initiatives resulted in the adoption of new technologies, including

...new, high-yielding varieties (HYVs) of cereals, especially dwarf wheats and rices, in association with chemical fertilizers and agro-chemicals, and with controlled water-supply (usually involving irrigation) and new methods of cultivation, including mechanization. All of these together were seen as a 'package of practices' to supersede 'traditional' technology and to be adopted as a whole.

Both the Ford Foundation and the Rockefeller Foundation were heavily involved.^[3] One key leader was Norman Borlaug, the "Father of the Green Revolution", who received the Nobel Peace Prize in 1970. He is credited with saving over a billion people from starvation. The basic approach was the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.

The term "Green Revolution" was first used in a March 8, 1968, speech by the administrator of the U.S. Agency for International Development (USAID), William S. Gaud, who noted the spread of the new technologies: "These and other developments in the field of agriculture contain the makings of a new revolution. It is not a violent Red Revolution like that of the Soviets, nor is it a White Revolution like that of the Shah of Iran. I call it the Green Revolution."^[4][5]

History

In Mexico

It has been argued that "during the twentieth century two 'revolutions' transformed rural Mexico: the Mexican Revolution (1910–1920) and the Green Revolution (1950–1970)".^[6] With the support of the Mexican government, the U.S. government, the United Nations, the Food and Agriculture Organization (FAO), and the Rockefeller Foundation, Mexico made a concerted effort to transform agricultural productivity, particularly with irrigated rather than dry-land cultivation in its northwest, to solve its problem of lack of food self-sufficiency.^[7] In the center and south of Mexico, where large-scale production faced challenges, agricultural production languished.^[8] Increased production meant food self-sufficiency in Mexico to feed its growing and urbanizing population, with the number of calories consumed per Mexican increasing.^[9] Technology was seen as a valuable way to feed the poor, and would relieve some pressure of the land redistribution process.^[10]

Mexico was the recipient of Green Revolution knowledge and technology,it was an active participant with financial support from the government for agriculture as well as Mexican agronomists. Although the Mexican Revolution had broken the back of the hacienda system and land reform in Mexico had by 1940 distributed a large expanse of land in central and southern Mexico, agricultural productivity had fallen. During the administration of Manuel Avila Camacho (1940–46), the government put resources into developing new breeds of plants and partnered with the Rockefeller Foundation.^[11] In 1943, the Mexican government founded the International Maize and Wheat Improvement Center (CIMMYT), which became a base for international agricultural research.

Agriculture in Mexico had been a sociopolitical issue, a key factor in some regions' participation in the Mexican Revolution. It was also a technical issue, which the development of a cohort trained agronomists, who were to advise peasants how to increase productivity.^[12] In the post-World War II era, the government sought development in agriculture that bettered technological aspects of agriculture in regions that were not dominated by small-scale peasant cultivators. This drive for transforming agriculture would have the benefit of keeping Mexico self-sufficient in food and in the political sphere with the Cold War, potentially stem unrest and the appeal of Communism.^[11] Technical aid can be seen as also serving political ends in the international sphere. In Mexico, it also served political ends, separating peasant agriculture based on the ejido and considered one of the victories of the Mexican Revolution, from agribusiness that requires large-scale land ownership, irrigation, specialized seeds, fertilizers, and pesticides, machinery, and a low-wage paid labor force.

The government created the Mexican Agricultural Program (MAP) to be the lead organization in raising productivity. One of their successes was wheat production, with varieties the agency's scientists helped create dominating wheat production as early as 1951 (70%), 1965 (80%), and 1968 (90%).^[13] Mexico became the showcase for extending the Green Revolution to other areas of Latin America and beyond, into Africa and Asia. New breeds of maize, beans, along with wheat produced bumper crops with proper inputs (such as fertilizer and pesticides) and careful cultivation. Many Mexican farmers who had been dubious about the scientists or hostile to them (often a mutual relationship of discord) came to see the scientific approach to agriculture worth adopting.^[14]

In rice: IR8 and the Philippines

In 1960, the Government of the Republic of the Philippines with the Ford Foundation and the Rockefeller Foundation established IRRI (International Rice Research Institute). A rice crossing between Dee-Geo-woo-gen and Peta was done at IRRI in 1962. In 1966, one of the breeding lines became a new cultivar, IR8.^[15] IR8 required the use of fertilizers and pesticides, but produced substantially higher yields than the traditional cultivars. Annual rice production in the Philippines increased from 3.7 to 7.7 million tons in two decades.^[16] The switch to IR8 rice made the Philippines a rice exporter for the first time in the 20th century.^[17]

Start in India

In 1961, India was on the brink of mass famine.^{[additional citation(s) needed][18]} Norman Borlaug was invited to India by the adviser to the Indian minister of agriculture C. Subramaniam. Despite bureaucratic hurdles imposed by India's grain monopolies, the Ford Foundation and Indian government collaborated to import wheat seed from the International Maize and Wheat Improvement Center (CIMMYT). Punjab was selected by the Indian government to be the first site to try the new crops because of its reliable water supply and a history of agricultural success. India began its own Green Revolution program of plant breeding, irrigation development, and financing of agrochemicals.^[19]

India soon adopted IR8 – a semi-dwarf rice variety developed by the International Rice Research Institute (IRRI) that could produce more grains of rice per plant when grown with certain fertilizers and irrigation.^[20] In 1968, Indian agronomist S.K. De Datta published his findings that IR8 rice yielded about 5 tons per hectare with no fertilizer, and almost 10 tons per hectare under optimal conditions. This was 10 times the yield of traditional rice.^[21] IR8 was a success throughout Asia, and dubbed the "Miracle Rice". IR8 was also developed into Semi-dwarf IR36.

Wheat yields in least developed countries since 1961, in kilograms per hectare.

In the 1960s, rice yields in India were about two tons per hectare; by the mid-1990s, they had risen to six tons per hectare. In the 1970s, rice cost about $550 a ton; in 2001, it cost under $200 a ton.^[22] India became one of the world's most successful rice producers, and is now a major rice exporter, shipping nearly 4.5 million tons in 2006.

Consultative Group on International Agricultural Research – CGIAR

In 1970, foundation officials proposed a worldwide network of agricultural research centers under a permanent secretariat. This was further supported and developed by the World Bank; on 19 May 1971, the Consultative Group on International Agricultural Research (CGIAR) was established. co-sponsored by the FAO, IFAD and UNDP. CGIAR has added many research centers throughout the world.

CGIAR has responded, at least in part, to criticisms of Green Revolution methodologies. This began in the 1980s, and mainly was a result of pressure from donor organizations.^[23] Methods like Agroecosystem Analysis and Farming System Research have been adopted to gain a more holistic view of agriculture.

Brazil's agricultural revolution

Brazil's vast inland cerrado region was regarded as unfit for farming before the 1960s because the soil was too acidic and poor in nutrients, according to Norman Borlaug. However, from the 1960s, vast quantities of lime (pulverised chalk or limestone) were poured on the soil to reduce acidity. The effort went on for decades; by the late 1990s, between 14 million and 16 million tonnes of lime were being spread on Brazilian fields each year. The quantity rose to 25 million tonnes in 2003 and 2004, equalling around five tonnes of lime per hectare. As a result, Brazil has become the world's second biggest soybean exporter. Soybeans are also widely used in animal feed, and the large volume of soy produced in Brazil has contributed to Brazil's rise to become the biggest exporter of beef and poultry in the world.^[24] Several parallels can also be found in Argentina's boom in soybean production as well.^[25]

Problems in Africa

There have been numerous attempts to introduce the successful concepts from the Mexican and Indian projects into Africa.^[26] These programs have generally been less successful. Reasons cited include widespread corruption, insecurity, a lack of infrastructure, and a general lack of will on the part of the governments. Yet environmental factors, such as the availability of water for irrigation, the high diversity in slope and soil types in one given area are also reasons why the Green Revolution is not so successful in Africa.^[27]

A recent program in western Africa is attempting to introduce a new high-yielding 'family' of rice varieties known as "New Rice for Africa" (NERICA). NERICA varieties yield about 30% more rice under normal conditions, and can double yields with small amounts of fertilizer and very basic irrigation. However, the program has been beset by problems getting the rice into the hands of farmers, and to date the only success has been in Guinea, where it currently accounts for 16% of rice cultivation.^[28]

After a famine in 2001 and years of chronic hunger and poverty, in 2005 the small African country of Malawi launched the "Agricultural Input Subsidy Program" by which vouchers are given to smallholder farmers to buy subsidized nitrogen fertilizer and maize seeds.^[29] Within its first year, the program was reported to have had extreme success, producing the largest maize harvest of the country's history, enough to feed the country with tons of maize left over. The program has advanced yearly ever since. Various sources claim that the program has been an unusual success, hailing it as a "miracle".^[30]

Agricultural production and food security

Technologies

New varieties of wheat and other grains were instrumental to the green revolution.

The Green Revolution spread technologies that already existed, but had not been widely implemented outside industrialized nations. Two kinds of technologies were used in the Green Revolution and aim at cultivation and breeding area respectively. The technologies in cultivation are targeted at providing excellent growing conditions, which included modern irrigation projects, pesticides, and synthetic nitrogen fertilizer. The breeding technologies aimed at improving crop varieties developed through the conventional, science-based methods available at the time. These technologies included hybrids, combining modern genetics with selections.^[31]

High-Yielding Varieties

The novel technological development of the Green Revolution was the production of novel wheat cultivars. Agronomists bred cultivars of maize, wheat, and rice that are generally referred to as HYVs or "high-yielding varieties". HYVs have higher nitrogen-absorbing potential than other varieties. Since cereals that absorbed extra nitrogen would typically lodge, or fall over before harvest, semi-dwarfing genes were bred into their genomes. A Japanese dwarf wheat cultivar Norin 10 developed by a Japanese agronomist Gonjiro Inazuka, which was sent to Orville Vogel at Washington State University by Cecil Salmon, was instrumental in developing Green Revolution wheat cultivars. IR8, the first widely implemented HYV rice to be developed by IRRI, was created through a cross between an Indonesian variety named "Peta" and a Chinese variety named "Dee-geo-woo-gen".^[32] In the 1960s, when a food crisis happened in Asia, the spread of HYV rice was aggravated intensely.^[33]

Dr. Norman Borlaug, who is usually recognized as the "Father of the Green Revolution", bred rust-resistant cultivars which have strong and firm stems, preventing them from falling over under extreme weather at high levels of fertilization. CIMMYT(Centro Internacional de Mejoramiento de Maiz y Trigo—International Center for Maize and Wheat Improvement) conducted these breeding programs and helped spread high-yielding varieties in Mexico and countries in Asia like India and Pakistan. These programs successfully led the harvest double in these countries.^[31]

Plant scientists figured out several parameters related to the high yield and identified the related genes which control the plant height and tiller number.^[34] With advances in molecular genetics, the mutant genes responsible for Arabidopsis thaliana genes (GA 20-oxidase,^[35] ga1,^[36] ga1-3^[37]), wheat reduced-height genes (Rht)^[38] and a rice semidwarf gene (sd1)^[39] were cloned. These were identified as gibberellin biosynthesis genes or cellular signaling component genes. Stem growth in the mutant background is significantly reduced leading to the dwarf phenotype. Photosynthetic investment in the stem is reduced dramatically as the shorter plants are inherently more stable mechanically. Assimilates become redirected to grain production, amplifying in particular the effect of chemical fertilizers on commercial yield.

HYVs significantly outperform traditional varieties in the presence of adequate irrigation, pesticides, and fertilizers. In the absence of these inputs, traditional varieties may outperform HYVs. Therefore, several authors have challenged the apparent superiority of HYVs not only compared to the traditional varieties alone, but by contrasting the monocultural system associated with HYVs with the polycultural system associated with traditional ones.^[40]

Production increases

Cereal production more than doubled in developing nations between the years 1961–1985.^[41] Yields of rice, maize, and wheat increased steadily during that period.^[41] The production increases can be attributed roughly equally to irrigation, fertilizer, and seed development, at least in the case of Asian rice.^[41]

While agricultural output increased as a result of the Green Revolution, the energy input to produce a crop has increased faster,^[42] so that the ratio of crops produced to energy input has decreased over time. Green Revolution techniques also heavily rely on chemical fertilizers, pesticides and herbicides and rely on machines, which as of 2014 rely on or are derived from crude oil, making agriculture increasingly reliant on crude oil extraction.^[43] Proponents of the Peak Oil theory fear that a future decline in oil and gas production would lead to a decline in food production or even a Malthusian catastrophe.^[44]
 

World population 1950–2010

Effects on food security

The effects of the Green Revolution on global food security are difficult to assess because of the complexities involved in food systems.

The world population has grown by about five billion^[45] since the beginning of the Green Revolution and many believe that, without the Revolution, there would have been greater famine and malnutrition. India saw annual wheat production rise from 10 million tons in the 1960s to 73 million in 2006.^[46] The average person in the developing world consumes roughly 25% more calories per day now than before the Green Revolution.^[41] Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by about 160%.^[47]

The production increases fostered by the Green Revolution are often credited with having helped to avoid widespread famine, and for feeding billions of people.^[48]

There are also claims that the Green Revolution has decreased food security for a large number of people. One claim involves the shift of subsistence-oriented cropland to cropland oriented towards production of grain for export or animal feed. For example, the Green Revolution replaced much of the land used for pulses that fed Indian peasants for wheat, which did not make up a large portion of the peasant diet.^[49]

Food security

Malthusian criticism

Some criticisms generally involve some variation of the Malthusian principle of population. Such concerns often revolve around the idea that the Green Revolution is unsustainable,^[50] and argue that humanity is now in a state of overpopulation or overshoot with regards to the sustainable carrying capacity and ecological demands on the Earth.

Although 36 million people die each year as a direct or indirect result of hunger and poor nutrition,^[51] Malthus's more extreme predictions have frequently failed to materialize. In 1798 Thomas Malthus made his prediction of impending famine.^[52] The world's population had doubled by 1923 and doubled again by 1973 without fulfilling Malthus's prediction. Malthusian Paul R. Ehrlich, in his 1968 book The Population Bomb, said that "India couldn't possibly feed two hundred million more people by 1980" and "Hundreds of millions of people will starve to death in spite of any crash programs."^[52] Ehrlich's warnings failed to materialize when India became self-sustaining in cereal production in 1974 (six years later) as a result of the introduction of Norman Borlaug's dwarf wheat varieties.^[52]

However, Borlaug was well aware of the implications of population growth. In his Nobel lecture he repeatedly presented improvements in food production within a sober understanding of the context of population. "The green revolution has won a temporary success in man's war against hunger and deprivation; it has given man a breathing space. If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the success of the green revolution will be ephemeral only. Most people still fail to comprehend the magnitude and menace of the "Population Monster"...Since man is potentially a rational being, however, I am confident that within the next two decades he will recognize the self-destructive course he steers along the road of irresponsible population growth..."

M. King Hubbert's prediction of world petroleum production rates. Modern agriculture is largely reliant on petroleum energy.^[53]

Famine

To some modern Western sociologists and writers, increasing food production is not synonymous with increasing food security, and is only part of a larger equation. For example, Harvard professor Amartya Sen wrote that large historic famines were not caused by decreases in food supply, but by socioeconomic dynamics and a failure of public action.^[54] Economist Peter Bowbrick disputes Sen's theory, arguing that Sen relies on inconsistent arguments and contradicts available information, including sources that Sen himself cited.^[55] Bowbrick further argues that Sen's views coincide with that of the Bengal government at the time of the Bengal famine of 1943, and the policies Sen advocates failed to relieve the famine.^[55]

Quality of diet

Some have challenged the value of the increased food production of Green Revolution agriculture. Miguel A. Altieri, (a pioneer of agroecology and peasant-advocate), writes that the comparison between traditional systems of agriculture and Green Revolution agriculture has been unfair, because Green Revolution agriculture produces monocultures of cereal grains, while traditional agriculture usually incorporates polycultures.^{[citation needed]}

These monoculture crops are often used for export, feed for animals, or conversion into biofuel. According to Emile Frison of Bioversity International, the Green Revolution has also led to a change in dietary habits, as fewer people are affected by hunger and die from starvation, but many are affected by malnutrition such as iron or vitamin-A deficiencies.^[27] Frison further asserts that almost 60% of yearly deaths of children under age five in developing countries are related to malnutrition.^[27]

The strategies developed by the Green Revolution focused on fend off starvation and was very successful in raising overall yields of cereal grains, but did not give sufficient relevance to nutritional quality.^[56] High yield-cereal crops have low quality proteins, with essential amino acid deficiencies, are high in carbohydrates, and lack balanced essential fatty acids, vitamins, minerals and other quality factors.^[56]

High-yield rice (HYR), introduced since 1964 to poverty-ridden Asian countries, such as the Philippines, was found to have inferior flavor and be more glutinous and less savory than their native varieties.^{[citation needed]} This caused its price to be lower than the average market value.^[57]
In the Philippines the introduction of heavy pesticides to rice production, in the early part of the Green Revolution, poisoned and killed off fish and weedy green vegetables that traditionally coexisted in rice paddies. These were nutritious food sources for many poor Filipino farmers prior to the introduction of pesticides, further impacting the diets of locals.^[58]

Political impact

A major critic^[59] of the Green Revolution, U.S. investigative journalist Mark Dowie, writes:^[60]

The primary objective of the program was geopolitical: to provide food for the populace in undeveloped countries and so bring social stability and weaken the fomenting of communist insurgency.

Citing internal Foundation documents, Dowie states that the Ford Foundation had a greater concern than Rockefeller in this area.^[61]

There is significant evidence that the Green Revolution weakened socialist movements in many nations. In countries such as India, Mexico, and the Philippines, technological solutions were sought as an alternative to expanding agrarian reform initiatives, the latter of which were often linked to socialist politics.^[62][63]

Socioeconomic impacts

The transition from traditional agriculture, in which inputs were generated on-farm, to Green Revolution agriculture, which required the purchase of inputs, led to the widespread establishment of rural credit institutions. Smaller farmers often went into debt, which in many cases results in a loss of their farmland.^[23][64] The increased level of mechanization on larger farms made possible by the Green Revolution removed a large source of employment from the rural economy.^[23] Because wealthier farmers had better access to credit and land, the Green Revolution increased class disparities, with the rich–poor gap widening as a result. Because some regions were able to adopt Green Revolution agriculture more readily than others (for political or geographical reasons), interregional economic disparities increased as well. Many small farmers are hurt by the dropping prices resulting from increased production overall.^{[citation needed]} However, large-scale farming companies only account for less than 10% of the total farming capacity. This is a criticism held by many small producers in the food sovereignty movement.

The new economic difficulties of small holder farmers and landless farm workers led to increased rural-urban migration. The increase in food production led to a cheaper food for urban dwellers, and the increase in urban population increased the potential for industrialization.^{[citation needed]}

According to a 2018 paper, a 10 percentage points increase in the use of high-yielding crop varieties in developing countries in the period 1960-2000 led to increases in GDP per capita of approximately 15 percent.^[65]

Environmental impact

Increased use of irrigation played a major role in the green revolution.

Biodiversity

The spread of Green Revolution agriculture affected both agricultural biodiversity (or agrodiversity) and wild biodiversity.^[58] There is little disagreement that the Green Revolution acted to reduce agricultural biodiversity, as it relied on just a few high-yield varieties of each crop.

This has led to concerns about the susceptibility of a food supply to pathogens that cannot be controlled by agrochemicals, as well as the permanent loss of many valuable genetic traits bred into traditional varieties over thousands of years. To address these concerns, massive seed banks such as Consultative Group on International Agricultural Research’s (CGIAR) International Plant Genetic Resources Institute (now Bioversity International) have been established (see Svalbard Global Seed Vault).

There are varying opinions about the effect of the Green Revolution on wild biodiversity. One hypothesis speculates that by increasing production per unit of land area, agriculture will not need to expand into new, uncultivated areas to feed a growing human population.^[66] However, land degradation and soil nutrients depletion have forced farmers to clear up formerly forested areas in order to keep up with production.^[67] A counter-hypothesis speculates that biodiversity was sacrificed because traditional systems of agriculture that were displaced sometimes incorporated practices to preserve wild biodiversity, and because the Green Revolution expanded agricultural development into new areas where it was once unprofitable or too arid. For example, the development of wheat varieties tolerant to acid soil conditions with high aluminium content, permitted the introduction of agriculture in sensitive Brazilian ecosystems such as Cerrado semi-humid tropical savanna and Amazon rainforest in the geoeconomic macroregions of Centro-Sul and Amazônia.^[66] Before the Green Revolution, other Brazilian ecosystems were also significantly damaged by human activity, such as the once 1st or 2nd main contributor to Brazilian megadiversity Atlantic Rainforest (above 85% of deforestation in the 1980s, about 95% after the 2010s) and the important xeric shrublands called Caatinga mainly in Northeastern Brazil (about 40% in the 1980s, about 50% after the 2010s — deforestation of the Caatinga biome is generally associated with greater risks of desertification). This also caused many animal species to suffer due to their damaged habitats.

Nevertheless, the world community has clearly acknowledged the negative aspects of agricultural expansion as the 1992 Rio Treaty, signed by 189 nations, has generated numerous national Biodiversity Action Plans which assign significant biodiversity loss to agriculture's expansion into new domains.

The Green Revolution has been criticized for an agricultural model which relied on a few staple and market profitable crops, and pursuing a model which limited the biodiversity of Mexico. One of the critics against these techniques and the Green Revolution as a whole was Carl O. Sauer, a geography professor at the University of California, Berkeley. According to Sauer these techniques of plant breeding would result in negative effects on the country's resources, and the culture:

"A good aggressive bunch of American agronomists and plant breeders could ruin the native resources for good and all by pushing their American commercial stocks… And Mexican agriculture cannot be pointed toward standardization on a few commercial types without upsetting native economy and culture hopelessly... Unless the Americans understand that, they'd better keep out of this country entirely. That must be approached from an appreciation of native economies as being basically sound".^[68]

Greenhouse gas emissions

According to a study published in 2013 in PNAS, in the absence of the crop germplasm improvement associated with the Green Revolution, greenhouse gas emissions would have been 5.2-7.4 Gt higher than observed in 1965–2004.^[69] High yield agriculture has dramatic effects on the amount of carbon cycling in the atmosphere. The way in which farms are grown, in tandem with the seasonal carbon cycling of various crops, could alter the impact carbon in the atmosphere has on global warming. Wheat, rice, and soybean crops account for a significant amount of the increase in carbon in the atmosphere over the last 50 years.^[70]

Dependence on non-renewable resources

Most high intensity agricultural production is highly reliant on non-renewable resources. Agricultural machinery and transport, as well as the production of pesticides and nitrates all depend on fossil fuels.^[71] Moreover, the essential mineral nutrient phosphorus is often a limiting factor in crop cultivation, while phosphorus mines are rapidly being depleted worldwide.^[72] The failure to depart from these non-sustainable agricultural production methods could potentially lead to a large scale collapse of the current system of intensive food production within this century.

Health impact

The consumption of the pesticides used to kill pests by humans in some cases may be increasing the likelihood of cancer in some of the rural villages using them.^[73] Poor farming practices including non-compliance to usage of masks and over-usage of the chemicals compound this situation.^[73] In 1989, WHO and UNEP estimated that there were around 1 million human pesticide poisonings annually. Some 20,000 (mostly in developing countries) ended in death, as a result of poor labeling, loose safety standards etc.^[74]

Pesticides and cancer

Contradictory epidemiologic studies in humans have linked phenoxy acid herbicides or contaminants in them with soft tissue sarcoma (STS) and malignant lymphoma, organochlorine insecticides with STS, non-Hodgkin's lymphoma (NHL), leukemia, and, less consistently, with cancers of the lung and breast, organophosphorous compounds with NHL and leukemia, and triazine herbicides with ovarian cancer.^[75][76]

Punjab case

The Indian state of Punjab pioneered green revolution among the other states transforming India into a food-surplus country.^[77] The state is witnessing serious consequences of intensive farming using chemicals and pesticides. A comprehensive study conducted by Post Graduate Institute of Medical Education and Research (PGIMER) has underlined the direct relationship between indiscriminate use of these chemicals and increased incidence of cancer in this region.^[78] An increase in the number of cancer cases has been reported in several villages including Jhariwala, Koharwala, Puckka, Bhimawali, and Khara.^[78]

Environmental activist Vandana Shiva has written extensively about the social, political and economic impacts of the Green Revolution in Punjab. She claims that the Green Revolution's reliance on heavy use of chemical inputs and monocultures has resulted in water scarcity, vulnerability to pests, and incidents of violent conflict and social marginalization.^[79]

A Greenpeace Research Laboratories investigation of 50 villages in Muktsar, Bathinda and Ludhiana districts revealed that twenty percent of the sampled wells had nitrate levels above WHO limits for drinking water. The 2009 study linked the nitrate pollution with high use of synthetic nitrogen fertilizers.^[80]

Norman Borlaug's response to criticism

Borlaug dismissed certain claims of critics, but also cautioned, "There are no miracles in agricultural production. Nor is there such a thing as a miracle variety of wheat, rice, or maize which can serve as an elixir to cure all ills of a stagnant, traditional agriculture."^[81]

Of environmental lobbyists, he said:

"some of the environmental lobbyists of the Western nations are the salt of the earth, but many of them are elitists. They've never experienced the physical sensation of hunger. They do their lobbying from comfortable office suites in Washington or Brussels...If they lived just one month amid the misery of the developing world, as I have for fifty years, they'd be crying out for tractors and fertilizer and irrigation canals and be outraged that fashionable elitists back home were trying to deny them these things".^[82]

The New Green Revolution

Although the Green Revolution has been able to improve agricultural output in some regions in the world, there was and is still room for improvement. As a result, many organizations continue to invent new ways to improve the techniques already used in the Green Revolution. Frequently quoted inventions are the System of Rice Intensification,^[83] marker-assisted selection,^[84] agroecology,^[85] and applying existing technologies to agricultural problems of the developing world.^[86] Current challenges for nations trying to modernize their agriculture include closing the urban-rural income gap, integration of smallholders into value chains, and maintain competitiveness in the market.^[87] However, in low-income countries, chronic problems such as poverty and hunger cause agricultural modernization efforts constrained.^[88] It is projected that global populations by 2050 will increase by one-third and as such will require a 70% increase in the production of food.^[89] As such, the Second Green Revolution will likely focus on improving tolerances to pests and disease in addition to technological input use efficiency.