|Solar geoengineering is an emerging technology that may help offset the effects of climate change when carbon dioxide reduction is done / Photo by Boscorelli via 123RF|
Scientists agree that it is important to cut greenhouse emissions at the soonest possible time in order to address global warming. However, global emissions are still increasing, therefore making researchers require more studies into other strategies that can be done, such as the use of solar geoengineering technologies.
Solar geoengineering is an emerging technology that may help offset the effects of climate change when carbon dioxide reduction is done. Included in the process is solar radiation management wherein the rays of the Sun are reflected back to space to reduce global warming.
These projects are still in their infancy but they have also shown great potential. The Solar Geoengineering Research Program at Harvard University is one of the high-profile programs that are researching solar radiation management. It may sound like a drastic measure by injecting stuff into the Earth's atmosphere and reflecting the sunlight. However, if you think about it, greenhouse gases were also injected into the atmosphere and it warmed the planet too.
Fast Action to Climate Change
The United Nations has issued a warning in 2018 that the next decade is critical in fighting climate change so that environmental issues can be addressed, such as extreme weather conditions, flood, and many more.
Solar geoengineering may be a possible solution wherein the manipulation of the Earth's environment can provide a fast and temporary solution to climate change as we try to reduce carbon emission. However, the process is meant to work together with lesser emissions and not as a replacement. The carbon in the atmosphere will last for a long time and it will also take a while for humans to switch to more sustainable energy sources. However, researchers are looking at geoengineering to bridge the gap.
|Aerosol injection into the stratosphere is a very popular strategy that can cool the planet / Photo by Mykhailo Polenok via 123RF|
Solar Radiation Management
All kinds of solar geoengineering methods have the same goal and that is to limit the effect of sunlight on the Earth but there are different approaches. Some methods are for reducing heat-trapping clouds, releasing aerosols into the stratosphere, sending a giant sunshade into orbit. These methods may lower warming but they will not reduce the greenhouse gases that are currently in the atmosphere. Hence, this will not solve the ocean acidification.
Based on research, according to carbonbrief.org, the use of solar geoengineering can lower the amount of carbon dioxide in the atmosphere by stemming permafrost melt, decreasing energy-sector emissions, and causing changes to the carbon cycle.
Marine Cloud Brightening
Making the marine clouds brighter can cause them to reflect more sunlight to space instead of toward the Earth. In this strategy, ships are used to spray saltwater into the clouds above the sea. The salt will act as “cloud condensation nuclei” that will help water vapor condense into liquid. The more water droplets there are, the clouds will appear brighter and larger. These brighter clouds will reflect sunlight away, according to Prof. Douglas Macmartin from Cornell University. He said, “It would simply be making those existing clouds just a little bit brighter and could help cool the planet.”
Marine cloud brightening can be used in specific areas, such as coral reefs. It can also cool a region off the Gulf of Mexico that may reduce the strength of hurricanes. However, these things are still just ideas.
Aerosol injection into the stratosphere is a very popular strategy. This is known as “stratospheric aerosol injection” and can cool the planet.
This is another option for blocking some effects of sunlight. In this theory, there is a fleet of ships that will churn up millions of microbubbles on the ocean surface, according to carbonbrief.org. The foam will reflect sunlight and cool the planet, according to Prof. Julian Evans, an emeritus professor in materials science from University College in London. However, this might have a negative effect on the marine ecosystems because there will be less light penetrating the ocean surface and marine plants. They may not be able to proceed with photosynthesis. This may cause an imbalance in the marine plants that can affect the ecosystem.
This is another option for reducing sunlight at the Earth's surface. Here, cirrus clouds are removed from the atmosphere. Cirrus clouds are thin clouds made of ice crystals. They reflect some sunlight but can also absorb long-wave radiation that can warm the Earth.
Sunshades in space
The last SRM technology is all about sending a giant mirror into space in order to reflect away more sunlight from the Earth. Prof. Govindasamy Bala from the Divecha Center for Climate Change at the Indian Institute of Science said that the size of the mirror would decide how much sunlight will reflect to space and cause a cooling effect.
While researchers and scientists have discussed solar geoengineering for many years already, very little research has been done. Daniel Cziczo, an atmospheric scientist at Massachusetts Institute of Technology, said that these theories and proposals are not logical. However, believers of geoengineering are still evaluating their options.