What's New

Geoengineering

Q. What is geoengineering? Discuss its impact on global food production. 

Answer:

Climate geoengineering refers to large-scale schemes for intervention in the earth’s oceans, soils and atmosphere with the aim of reducing the effects of climate change, usually temporarily.

Types of Geoengineering

The main categories of proposed geoengineering techniques are

• Solar radiation management: SRM techniques attempt to reflect sunlight back into space, and include a range of ideas, from orbiting mirrors, tonnes of sulphates sprayed into the stratosphere, and modifying clouds, plants and ice to make them more reflect more sunlight.
• Carbon dioxide removal: These proposals posit that it’s possible to suck carbon out of the atmosphere on a massive scale, using a combination of biological and mechanical methods, from seeding the ocean with iron pellets to create plankton blooms to creating forests of mechanical “artificial trees”.
• Earth Radiation Management: ERM proponents suggest that negative effects of climate change can be offset by allowing heat to escape into space – for example, by thinning cirrus clouds.

Impact of Geo Engineering on Food production

• The impact on agriculture will vary depending on the location and other climate factors like rainfall and sunlight.
• Climate change will have a negative impact on cold regions, including the potential negative effects of solar geoengineering (SAI). However, climatic interventions like SAI could potentially increase agricultural production in tropical regions.
• If climate change continues to go unchecked, crops will thrive in cold regions like Canada, Russia, northern US states, Scandinavia, and Scotland.

Other geoengineering techniques which affects food production:

Bio-energy with carbon capture and storage (BECCS)

• This process involves extracting bioenergy from biomass and simultaneously capturing and storing carbon, effectively removing it from the atmosphere.
• The biomass absorbs carbon dioxide from the atmosphere as it grows, which contributes to the carbon content in the biomass.
• Energy is obtained in various forms (such as electricity, heat, and biofuels) by using biomass through processes like combustion, fermentation, and pyrolysis.

Ocean fertilisation or ocean nourishment

• Ocean fertilisation is a method of manipulating the environment by adding nutrients to the ocean in order to boost marine food production and reduce carbon dioxide levels in the atmosphere. Various techniques, such as using iron, urea, and phosphorus, have been suggested for this purpose.

Soil carbon sequestration (SCS)

• Due to the rising levels of carbon dioxide in the atmosphere and the increasing acidity of oceans, soils have the capacity to absorb carbon dioxide and act as a storage system for it.
• Storing carbon in soils has the capacity to compensate for 15% of greenhouse gas emissions produced by burning fossil fuels each year.
• Soil organic carbon originates from various sources such as plants, animals, microbes, leaves, and wood, primarily located within the top meter of soil.
• Numerous factors, including temperature, rainfall, vegetation, soil management, and land-use changes, influence the amount of SOC present in the soil and its subsequent alterations.

Marine cloud brightening (MCB)

• MCB is a method that aims to divert sunlight from the earth by increasing the thickness and reflectivity of marine clouds through the spraying of sea salt or other particles.

Cirrus cloud thinning (CCT)

• CCT and marine cloud brightening have contrasting effects. Cirrus clouds, which are found at high altitudes, are not effective in reflecting solar radiation back into space and instead trap long-wave radiation on earth.
• CCT suggests reducing their density through cloud seeding, thus allowing more long-wave radiation to be released.

Conclusion

Geoengineering poses risks and side effects, such as harm to the ozone layer and unintended alterations in global rainfall. Once initiated, it would be risky to discontinue unless significant carbon reduction occurs, lowering temperatures below a safe level that impacts agriculture.