In a world that is being severely affected by climate change, caused by global warming, large-scale solutions have been proposed. One of these solutions is called geoengineering. Geoengineering (also known as climate engineering) is about manipulating the Earth’s processes to counter global warming. These are also very expensive. You can almost consider these to be last resort. There are many techniques that have been put forward, which lie in two categories of geoengineering: solar radiation management and carbon dioxide removal.
Solar radiation management involves reflection of solar radiation (Sun’s energy) away from the Earth and back into space. Of course, this would only reflect a small proportion of the solar radiation as reflecting all would first of all be virtually impossible and we would not be able to survive! The main reason for doing this would be to help try and stabilise temperatures on Earth. This would mean greenhouse gases in the atmosphere would absorb less and hence this would reduce the rate at which global warming takes place. It is important to note that this method would not reduce the amount of greenhouse gases found in the atmosphere.
There are only a few techniques proposed. The first one involves increasing the albedo (percentage of the Sun’s energy reflected at the surface of the Earth). This is done by increasing the reflectiveness of clouds, or even the land, so that more of the solar radiation is reflected away from the earth. The second technique involves the actual blocking of the sunlight from reaching the earth using specially constructed mirrors. The third method involves putting special reflective particles into the atmosphere to reflect the solar radiation from reaching the earth.
Carbon dioxide removal is somewhat self explanatory, but is about removing the carbon dioxide out of the atmosphere. This would mean that it would counter any increases of the green house effect and ocean acidification. For this to make any kind of significant difference, it would have to be implemented on a global scale. There are many methods to do this with some being rather straightforward and others far more complex.
A very simple technique is afforestation. By planting more trees, they will take in more carbon dioxide, meaning less will reach the atmosphere. A complex technique is ocean fertilisation. This involves adding nutrients to the oceans to encourage greater marine life and production. A good example is depositing iron, where the ocean is iron deficient, which in theory should boost production. It should be noted that there is legislation to stop anyone from just putting nutrients in the ocean. Another method involves exposing very large amounts of minerals that are known to chemically react with the carbon dioxide found in the atmosphere and this will result in a compound forming. This will be stored in soils or the ocean, etc.
It is possible to actually capture the carbon dioxide in the air through large machines, which can then be stored in the ground, for industry use etc. The use of carbon capture and storage is another technique in particular when creating bio-energy. This means that when you burn biomass (organic matter), you simply capture the carbon dioxide released and store it in the ground normally. It can also be done so that the carbon mixes with the soil and this would ‘lock’ it up. The final method involves putting normally calcium-silicate rocks into the ocean, which will over time increase the amount of carbon that can be stored in the ocean and try to decrease ocean acidification.
Geoengineering could potentially play a part in our future. But getting a significant number of nations involved in such large scale projects would be no easy task especially when it requires large investments and when these methods have issues. Some of the main issues are that some are still in the research stage and even when some of these methods have been tested (ocean fertilisation of iron), they did not provide the results hoped for. In theory, we should not have to go to such drastic lengths to combat global warming. My opinion on the matter is that we live in a world where we are very reluctant to change our ways for the sake of global warming, so such extreme techniques could very well be used in the future. Then again, some already argue that we are too late to stop this.