Wouldn’t it be great if we could fight climate change with some sort of huge sun umbrella, or at least reduce the heat in major cities caused by global warming and also fight drought? Well researchers from the University of Cape Town propose to do just that.
Think about it: If you live in place like Miami or Tel Aviv then you know how awful it gets these days in summer time with the combination of heat and humidity. Israel joined much of the world just this past summer when it set record breaking high temperatures. And as if that was not enough, new records set in May were broken again in August.
Now blocking the sunlight is not such a good idea. Obviously we need it, plants need it. But reducing it at the hottest times of the year, and just over the densely populated urban centers, could have many benefit.
A drop in temperatures in major cities every summer would lead to a large reduction in energy consumption, which would be good for the environment and save people money. There would be less need for air-conditioning and so forth. Also, every summer many people, largely elderly need to be hospitalized or even die due to sun exposure in extreme heat. This could be avoided.
Also the new extreme heat levels are a cause of more draught around the world. Reducing the high temperatures can reverse this. Now imagine such an umbrella over the Kinneret, protecting Israel’s main source of drinking water.
So how would this work?
Well the research, published in a study in Environmental Research Letters, state that artificially dimming the sun by injecting reflective particles into the upper atmosphere could help reduce the likelihood of “Day Zero” level droughts in Cape Town by as much as 90%.
So no, they would not build incredibly huge umbrellas or anything like that. The idea here is that certain particles could be put into the atmosphere which would dim the Sun’s light.
The research team assessed the potential impact of “solar radiation management” geoengineering (SRM) on drought and water availability. They used a climate model to quantify how likely droughts as severe as the “Day Zero” event, that nearly caused the City of Cape Town to run out of water in the summer of 2017-2018, would become near the end of the century with and without SRM.
The researchers explain that SRM is a “controversial proposal for reducing some of the risks of climate change. If it were implemented, it would involve blocking a small amount of solar radiation from reaching the Earth’s surface, by, for example, injecting reflective aerosols into the upper atmosphere. If emissions cuts prove insufficient, SRM might well be the only way to keep global temperature rises below the global target of 2°C, but the approach has its limits.”
But this would just be a treatment, not a cure. The damage that has already been done to the environment would remain as long as greenhouse gas emissions are not reduced.
Lead author, Dr Romaric C. Odoulami, said: “Our findings suggest that SRM could help to lower future risks of severe droughts in Cape Town. These are a substantial, new contribution to our understanding of the possible impact of SRM at the local scale, using the lens of an iconic climate disaster, the Cape Town “Day Zero” drought. These findings must be seen in context, however. A change of location, model, or SRM deployment design might produce significantly different results.”