According to Paris Agreement in 2015, world leaders agreed to limit the emissions of greenhouse gases and keep the temperature at 1.5°C by the end of this century to avoid consequences of climate change.
Currently, scientists have considered warming of 2°C above pre-industrial level the threshold of global warming. If we cross this limit, there are chances of weather to become extreme; resulting in storms, droughts and rise in sea levels.
Scientists estimate that if climate change continues at this rate, by 2050, we will exceed the two degree limit. And with the intention of Donald Trump to withdraw USA from Paris Agreement, the chances of achieving the target looks unlikely.
What is Geoengineering?
Geoengineering is one of the most controversial subject in the field of climate change. It involves the manipulation of the earth’s natural system on large scale in an attempt to slow global warming.
For the last ten years, scientists across the world have been discussing the prospective of geoengineering.
Geoengineering can be defined as any attempt to balance earth climate through manipulation of earth’s land, ocean and atmosphere.
For example, if all people in China plant a tree to capture carbon dioxide from atmosphere in one day, it could change the planet climate and it may be called geoengineering. If everybody starts using recycled paper which could save many trees, it is also called geoengineering. Installing thousands of wind turbines can also be considered as geoengineering of its kind.
Techniques of Geoengineering:
Geoengineering has two major types.
The first type involves the removal of carbon dioxide from the atmosphere in the following ways:
• Afforestation: Tree plantation on global scale.
• Bio-energy with carbon capture: Burning biomass to create energy and capturing carbon dioxide
• Ambient Air Capture: Removing carbon dioxide from the atmosphere and storing it.
• Ocean Fertilization: adding substances to the ocean to increase production which could withdraw carbon dioxide from the atmosphere.
The other method is more fundamental and involves the solar radiation management. i.e reducing the amount of heat absorbed by the earth by reflecting it back into space:
• Albedo enhancement: increasing reflectiveness of cloud so that sun’s heat is reflected back to space.
• Space reflectors: installing space reflectors into Earth’s orbit to block some sunlight.
• Stratospheric aerosols: releasing aerosol particles to reflect some sunlight
One geoengineering strategy to reduce greenhouse gases involves dumping chemicals into the ocean. The most weird –looking strategies of geoengineering aim to directly moderate the earth temperature, as if it had an adjustable thermostat.
One such approach was inspired by volcanoes. The eruption of volcanoes release sulfur dioxide into the atmosphere. In the atmosphere, this gas blocks the portion of sun’s heat, reflecting it back into space. Actually a single volcanic eruption can remarkably lower the temperature of entire hemisphere.
Scientists believe we could recreate this cooling effect by spraying sulfur aerosol into the atmosphere from the planes. According to their calculations, for one degree decrease in temperature, it would take 7,000 flights a day and it would cost 20 billion dollars per year. We would need to continue spraying these substances into the atmosphere for indefinite period of time or risk letting the earth temperature jump back up.
Another geoengineering proposal involves flying drones through cirrus clouds. The drones would spray dust like materials that cause the cloud’s water molecules to cluster together. This will allow more heat to escape into space and cool the earth’s temperature.
These ideas may sound like science fiction, but these are actually being investigated right now by research scientists at the world’s top universities.
Scientists are also afraid that governments and the fossil fuel industry will point to these techniques as an excuse to continue polluting.
For example, Rex Tillerson, the secretary of the state and former head of Exxon Mobil is a proponent of geoengineering and has called climate change an engineering problem. But despite all the risks, many climate scientists believe that geoengineering is an emergency measure that we can’t afford to ignore.
Is this cure worse than the disease?
1- The main objection to geoengineering is that its major effects could not be easy to predict. People already believe that climate change itself is big experiment with the future. But what would happen if we start tampering the climate? Scientists warn that geoengineering could change the earth’s climate forever.
2- Solar Radiation Management (SRM) involves introduction of particles into stratosphere. It can cause physical, political and cultural damage. It could change worldwide rainfall patterns, damage our ozone layer thus threatening lives of millions of people.
3- Geoengineering techniques take away scarce financial resources. It could cost $20 billion a year which could deprive other clean energy projects.
4- Blocking solar radiation could affect the weather and hydrological cycle, reduces precipitation and condemning hundreds of millions of people to drought.
5- The oceans would continue to become more acidic, continued acidification threatens the entire oceanic biological chain, from coral reefs right up to humans.
6- Aerosols from geoengineering would destroy ozone layer.
7- Once we put aerosols into the atmosphere, we cannot remove them
8- It is also not politically feasible. When 200 world leaders could not agree on small cut to their carbon dioxide emissions, how they can agree on geoengineering.
Different geoengineering procedures can affect the different countries to different extent. One procedure could benefit one country while could bring floods and droughts to other country. How could the threat of climate catastrophe bring all the world together? It is not possible.
Conclusion:
According to latest research by US researchers, geoengineering is no substitute for reducing carbon emissions.
“[T]he reports are on ‘climate intervention’ because the Academy panel rejects the widely used term ‘geoengineering’. Why? Because ‘we felt “engineering” implied a level of control that is illusory,’ explained Dr. Marcia McNutt who led the report committee.”
The scientists have emphasized to do more research on geoengineering:
“Geoengineering and research into it is not just about winners and losers, risks and benefits. It is not just a set of empirical questions. It is a profound social experiment.”
Jack Stilgoe
What do you think about geoengineering?
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References:
- http://www.newsweek.com/climate-change-geoengineering-artificially-cool-planet-640124
- https://greentumble.com/are-geoengineering-methods-safe-for-our-planet/
- https://www.theguardian.com/environment/2014/feb/25/geoengineering-side-effects-potentially-disastrous-scientists
- http://www.geoengineeringwatch.org/category/geoengineering/disinformation-geoengineering/