Despite being controversial why some people still think solar geoengineering is needed? Well the reason is climate change and rising earth temperature. Mainly the Sun is constantly throwing solar radiation at the Earth. The Earth surface and the Cloud reflects some of the radiation. But some heat stays in the Earth. Besides because of human being, emission of greenhouse gases increased and the result is global warming. As a result earth temperature is increasing. In the past 25 years the global average temperature has risen by 0.5 degree Celsius. In addition to that carbon dioxide in the atmosphere is making the Earth hotter. Even the concentration of carbon dioxide in the atmosphere has risen 15% since 1994.
How scientist got idea of solar geoengineering:
15th June 1991, media reported about the explosion of the ‘PINATUBO VOLCANO’ in the Philippines. It was the 2nd largest eruption in the century and emitted huge amounts of ash and gases. The volcano explosion was so powerful that it reached stratosphere. Stratosphere is located between 15 to 50 kilometers from the Earth surface. So the explosion was so huge that all the ash and gases reached there.
But scientist found out a surprising thing because of this event. Mainly the planet cooled by about half a degree Celsius in the following months. And it continued for four year. So they researched about it and found that tiny particles called aerosols reflected the sunlight back into space. And the particle came into the atmosphere from the explosion. From here scientist got idea of stratospheric aerosol injection. Which is called solar geoengineering.
solar geoengineering:
To cool the planet aerosol have to be injected into the atmosphere over decades and across large areas. In a Harvard and Yale study they imagined building 95 planes that would make 60 thousands flights a year. They will spread hundreds of thousands tons of sulfur dioxide into the stratosphere every year. After 15 years they say world would cool down by o.3 degree Celsius. Not only planes in other research it is said that balloons, towers can be used to get the aerosol into the air. To lower the temperature with this technology by one degree we’d have to spend an estimated 18 billion dollar per year.
The possible side effect:
Because of this idea acid rain can happen. And as a result stratosphere can heat up which can lead more rise of temperature. Also the ozone layer is located here. Acid is bad for ozone layer. We human being already damaged ozone layer. But it’s repairing by itself. In a study it is said that by 2040 ozone will be repaired in most part of the world and by 2060 the big hole of ozone will be healed. But because of geoengineering the ozone layer will be further damaged. Ozone absorbs harmful UV rays from the sun. So the damage of this layer will result more skin cancer in human and also the environment will be at risk. A lot of plant will die because photosynthesis will be hindered. The DNA of human and animal will be damaged. Also the weather will be extreme if ozone is more damaged.
It can effect rain pattern and we might cause a region that is already suffering from drought to have even less water or no water. Could lead to reduce rainfall in country like India, Africa. As a result agriculture will be affected and we will have less food. So water and food security will be at threat. Also natural calamities will increase. Flood and drought can happen anytime. As it will result to heavy rain or no rain situation. Even some country can misuse it against other country as climate weapon. Potentially resulting in violent conflict. Besides solar geoengineering does not reduce carbon dioxide level, so the oceans will continue to absorb carbon dioxide and will become incredibly acidic. As a result marine life will be destroyed.
What if it fails?
If the project stops because of political shifts or technical failure or because of any other reason, the temperature will increase 2 to 4 time faster than now. Which will cause climate changes. The world will heat up much faster that we can’t cope up with it. The increase in temperature that would take 50 years today, could happen in just 10 years if it fails. Also number of skin cancer will increase. Food and water cycle won’t be the same how it is today. Basically we are threating the life of billion of people for doing some experiment. Which can be successful. Again if it fails no one know what will happen. Because of the rise of temperature the ice will melt more quickly compared to now. Which will lead to extreme water rise of the oceans. So scientist have to be more careful about the specific research.