IASNOVA
Climate engineering, an application of geoengineering, is the deliberate and large-scale intervention in Earth’s climatic system with the aim of reducing global warming.
Climate engineering has two categories of technologies-
1.carbon dioxide removal
2.solar radiation management.
Solar geoengineering is a term used to describe a group of hypothetical technologies that could, in theory, counteract temperature rise by reflecting more sunlight away from the Earth’s surface.
A. Carbon Dioxide Removal
Methods
- Creating biochar (i.e. in biomass-fired thermal power plants), for mixing into the soil to create terra preta
- Bio-energy with carbon capture and storage to sequester carbon and simultaneously provide energy
- Carbon air capture to remove carbon dioxide from ambient air
- Afforestation, reforestation and forest restoration to absorb carbon dioxide
- Ocean afforestation and ocean fertilization (which includes iron fertilization of the oceans)
Terms
Biochar– is charcoal used as a soil amendment for both carbon sequestration and soil health benefits. Biochar is a stable solid, rich in carbon, and can endure in soil for thousands of years.Like most charcoal, biochar is made from biomass via pyrolysis. Biochar is under investigation as a viable approach for carbon sequestration, as it has the potential to help mitigate global warming and climate change.
Ocean afforestation – is a proposal for farming seaweed for carbon removal. After harvesting the seaweed decomposes into biogas, (60% methane and 40% carbon dioxide) in an anaerobic digester. The methane can be used as a biofuel, while the carbon dioxide can be stored to keep it from the atmosphere.
Ocean fertilization or ocean nourishment is a type of climate engineering based on the purposeful introduction of nutrients to the upper ocean to increase marine food production and to remove carbon dioxide from the atmosphere.
Iron fertilization is the intentional introduction of iron to iron-poor areas of the ocean surface to stimulate phytoplankton production. This is intended to enhance biological productivity and/or accelerate carbon dioxide sequestration from the atmosphere.
B. Solar Radiation Management
Solar radiation management techniques would seek to reduce sunlight absorbed . This would be achieved by deflecting sunlight away from the Earth, or by increasing the reflectivity (albedo) of the atmosphere or the Earth’s surface.
Methods
1. Stratospheric Aerosol injection
It could cool the planet in a similar way to a large volcanic eruption. When a volcano erupts, it sends an ash cloud high into the atmosphere. The sulphur dioxide released in the plume combines with water to form sulfuric acid aerosols, which are able to reflect incoming sunlight.Researchers have proposed that artificially introducing aerosols into the atmosphere – via a plane or a high-altitude balloon – could have a similar cooling effect.
2. Marine cloud brightening
In theory, this could involve using ships to spray saltwater into the clouds above the sea.Once airborne, the salt particles would act as “cloud condensation nuclei”, meaning they would facilitate the condensation of water vapour into liquid. As more water droplets are created, clouds would appear larger and brighter.These brighter clouds would reflect away more sunlight.
3. High-albedo crops and buildings
Idea of increasing the albedo of buildings in order to reflect more sunlight. Put simply, this would involve making rooftops and walls brighter – by painting them white, for example.
Scientists have also suggested that the same technique could be applied to crops, possibly by introducing genes that would give plants a waxy sheen.
4. Ocean mirror
In theory, this would involve using a fleet of sea vessels to churn up millions of tiny microbubbles on the ocean surface.
This seafoam would reflect away sunlight, cooling the planet.
5. Cirrus Cloud thinning
Asked in previous year Prelims Exam.
In theory, aerial vehicles such as drones could be used to deliver and then inject solid aerosol particles, such as desert dust or pollen, into cirrus clouds. Seeding the clouds in this way would cause them to dissipate more quickly, lessening their overall warming effect.
6. Space Sunshades
It involves sending a giant mirror – or fleet of mirrors – into orbit in order to reflect away more sunlight from the Earth.
Pls go through this article on some terms as well-
https://iasnova.com/carbon-sequestrationocean-acidification-and-other-important-terms/
