Since the issue of global warming emerged, greenhouse gases have been portrayed as the villain. What would happen if we were to eliminate these wicked greenhouse gases? The current average surface temperature of the Earth is about +15°C. This temperature makes the climate comfortable for humans. However, if the greenhouse effect were to disappear, the Earth’s temperature would drop to about -18°C. Our comfortable living environment is only possible because of a moderate greenhouse effect. The problem is when the greenhouse effect “excessively” works. Many countries are trying to prevent global warming by reducing fossil fuel emissions. However, fossil fuel consumption continues to increase. If this method fails, some will consider another solution. This time, we will consider this alternative solution (blocking sunlight).
In 1883, Indonesia’s Krakatoa volcano erupted, producing what is considered the loudest sound in history. The summer following this eruption, temperatures in the Northern Hemisphere dropped by 1.2°C. Major volcanic eruptions of this type release aerosols into the stratosphere. These aerosols, containing sulfuric acid droplets, reflect a certain percentage of the incoming sunlight back into space. Aerosols from major volcanic eruptions reflect sunlight, lowering temperatures on Earth. The Earth receives 340W of energy per square meter, reflects 100W, and absorbs 240W. Theoretically, if all 340W were reflected, the Earth would become a snowball Earth. Some estimates suggest that if fine aerosols were trapped in the ozone layer, around 200W could be reflected. Artificially trapping aerosols in the Arctic stratosphere for an extended period of time could potentially prevent the melting of Arctic ice. Protecting even the Arctic ice could act as a barrier against global warming.
One idea that has been proposed is to use this principle of reflection to launch a satellite equipped with a small mirror to reflect sunlight before it reaches the upper atmosphere. However, the concept of this orbiting mirror was shelved at a time when satellites were still expensive. Recently, this idea has become more realistic. Elon Musk and others have advocated solar power generation in space. It is said that the performance of AI is proportional to the amount of power it consumes, and AI has become a large consumer of electricity. The idea is that this large amount of electricity can be generated in space, where sunlight is uninterrupted. Inexpensive satellites are already in practical use. It might also be interesting to imagine blocking sunlight in space above the Arctic or Antarctic and using the blocked sunlight to generate electricity.
