We are faced with global eco-crises that are threatening to become a global ecocide. The global warming seems to have reached a point of no return and even if we somehow control the green house gases, the rising temperatures of the earth will not reach a full stop for a long time. The imbalance between the heat received by the earth and the heat radiated by it back into the atmosphere traps the heat within the atmosphere keeping the earth warmer day by day. This rising temperatures are said to produce drastic consequence on our climate in the future. While we as communities and individuals are invited to take responsibility and do our bit to respond to this global crises, science promises a way of dealing with the problem. The crises is born from a misuse of science and technology, hence, perhaps there is a solution in the right use of the same. Geo-engineering is a rapidly growing science that is trying to arrest the rising temperature of the earth and consequently the disastrous climate change.
We can imagine that the entire earth has become thermo flasks which due to the green house gases working as insulators keep the earth hot. Hence, atmospheric thermal bridges have to be created to dispatch the trapped heat and bring about cooling of the earth. We know heat moves from hotter spaces to cooler spaces. There are scientific techniques to decelerate or decrease global warming. One of the solutions proposed by some geo-engineers is to pump cold water from the depths of the ocean and recycle the hot water at the surface of seas. Others say that spraying of sulphur in the atmosphere with the help of aircrafts can keep the atmosphere cool. Today the geo-engineering techniques can be classified into three chief categories: Sunlight reflection methods (SRM), Earth radiation management (ERM) and Carbon dioxide removal (CDR). Most of these geo-engineering techniques are aimed at direct intervention in the energy balance of the earth in order to reduce global warming.
Scientists are considering several techniques to reflect the sun rays back to space. The hope is to reduce global warming by reducing the amount of light received on earth and its atmosphere. Several techniques like space solar reflectors, stratospheric injection of aerosol, seeding tropospheric clouds by salt aerosol or ice nucleation , giant mirrors orbiting the earth made of wire mesh or orbiting trillions of light mirrors of DVD size that will defect the light from the sun back to outer space. The principle is very simple. Scientists are trying to create numerous artificial mini-eclipses that will obscure the sun. Cloud whitening is another option that is being proposed by some scientists who propose that sea water can be pumped and sprayed in the air to produce fine sea salt crystals increasing the reflectivity of low altitude clouds.
The other techniques that are considered are earth radiation management (CRM). These techniques try to reflect a portion of light received by the earth back to the outer space. A simple change from dark roofs of our homes that trap heat to white roofs that reflect can deflect light in a large measure. Some even suggest that our roads have to be also painted white. Planting genetically engineered paler crops that reflect light from the earth is also under serious consideration. There are even more sophisticated techniques to dispel the light and heat from the earth. One of the very important one is carbon dioxide removal (CDR). Others talk about cooling the air in the desserts. CDR methods have biogeochemical limitations when employed at a global scale. But we have to respond to carbon dioxide accumulation in our atmosphere. Scientists propose that we can inject iron into the seas to rapidly increase the amount of phytoplankton that feeds of carbon dioxide. The most important way is to measure our carbon foot print.
Geo-engineering has its limitations and side effects. Some of the techniques are economically not sustainable. Some critiques are treating it as a bad idea as it will only encourage the abusers of nature. Yet its potentials to respond to global warming cannot be wished away. Hence, critical research on risk analysis and possible climate and health benefits has to be identified. Science can provide the way. But each of us has a great responsibility. Our collective effort will can save the planet earth for humanity and every other form of living organism. Little change in our life style can bring great solace to the poor and make life healthier and happier for all. What geo-engineering is trying to do is to provide a sun shade to our mother earth. But will this techno-fix bring other problems? We need more research and scrutiny to understand the long term effects of our measures to deal with global warming. Yes the earth needs a balm and science is not far away from healing the wounds of our common home.
