A new Harvard / MIT geoengineering study says that less is more


March 12, 2019 by Steve Hanley

There are many people who escape the threat of a planet overheating with these words: "When it is absolutely necessary, humanity will find a way to 'advance science' to out of the worst consequences. "These are largely the same people. who were sitting on the Titanic's fantail, listening to the band playing "Nearer My God To Thee" and expecting the captain and his team to do some sort of "science walk" out of the impending disaster.


Credit: Almay

The concept as a whole would be fun if it was not so sad. Basically, it is the same people who deny the work of climatologists and deny that the Earth is warming up. Why they place their trust in science on the one hand while denigrating scientists on the other is an enigma.

Geo-engineering is a quick fix for the world to continue to spill indefinitely millions of tons of carbon dioxide from burning fossil fuels into the atmosphere. Basically, it involves injecting huge amounts of sulfur dioxide – the substances emitted by volcanoes during their eruption – into the stratosphere, which would prevent some of the sunlight provided by the sun from reaching the surface of the earth. 'air.

The Krakatoa effect

Call it Krakatoa effect. When this volcano erupted in 1883, it caused a period of global cooling because its dust and gases absorbed the sun. Some suggest that Edvard Munch's famous painting, The Scream, was not a surrealist composition created while the artist was under the influence of recreational drugs, but rather a faithful representation of the sky above the Norway at the time of his painting.

Many critics of geoengineering suggest that it is a blunt instrument that no one knows how to accurately control. This could easily disrupt climates of one part of the world more than others, causing floods for some and droughts for others.

A new study by Harvard and MIT

But a study published by Harvard and MIT scientists in the journal Nature Climate change March 11 entitled "Halving global warming through idealized solar geoengineering mitigates major climate risks,"Suggests reducing the amount of sulfur dioxide by about half compared to what most advocates of geoengineering recommend to mitigate much of the damage that climate scientists say will result in rampant carbon emissions." .

Co-author Kerry Emanuel of MIT tells Science Daily"For years, geoengineering has been trying to offset greenhouse warming without paying too much attention to other quantities such as precipitation and storms. This study shows that a more modest reduction in global warming by engineering can lead to better results for the climate as a whole. "

"The analogy is not perfect, but solar geoengineering is a bit like a drug that treats high blood pressure. An overdose would be harmful, but a well chosen dose could reduce your risk. Of course, it's better not to have high blood pressure at first, but once you've had it, while making healthier lifestyle choices, it's good to consider treatments that could reduce your risk. "

David Keith, of the Harvard Faculty of Engineering and Applied Science, says, "Some of the problems identified in previous studies in which solar geo-engineering offsets any warming are examples of the old adage that the dose makes the poison. This study takes a big step forward by using the climate variables most relevant to human impacts and finds that no region defined by the IPCC is compounded by any of the key indicators of climate change. impact on the climate. Large uncertainties remain, but climate models suggest that geoengineering could generate surprisingly uniform benefits. "

Lead author Peter Irvine of Harvard added, "The places where solar geoengineering exacerbates climate change were the ones that experienced the least amount of climate change in the first place. Previous work had assumed that solar geoengineering would inevitably lead to winners and losers, with some regions suffering greater damage; our work challenges this hypothesis. We are seeing a significant reduction in climate risk as a whole, without increasing risks for all regions. "

Professor Keith tells The Guardian"I'm not saying we know it works and we should do it now. Indeed, I would absolutely oppose the deployment now. There is only a small group of people dealing with that, there is a lot of uncertainty. It is possible that solar geoengineering can actually significantly reduce climate-related risks for the most vulnerable. "

Some scientists are not convinced

Not everyone is so sure. Alan Robock, professor of geophysics and researcher at Rutgers University, tells The Guardian the study does not examine the potential effects of spraying aerosols in the atmosphere. "In this article, they focus on the temperature and availability of water in different regions – these are just two things that would change with stratospheric aerosols."

He adds that his studies are looking at 27 reasons why cooling the Earth with aerosols could be a bad idea, especially that the technology could cost hundreds of billions of dollars a year and raise complicated ethical questions, such as the right to see a blue sky. (See The scream, above.)

"We are not in a position yet to say whether, if global warming continues, we should decide to start spraying these substances in the stratosphere," he said. "The management of solar radiation, geoengineering would make it dangerous or the least dangerous? That's the question we have to answer and we do not have enough information. "

Some people suggest that the solution to global warming could consist of human engineering with social awareness rather than geoengineering of the environment. The world is made up of two types of people: those who make things move and those who wonder what has happened. Since the overwhelming majority of the population belongs to the latter category, the prospect of humanity taking realistic measures to combat global warming is imperceptibly reduced.

Keywords: Geoengineering, Harvard School of Engineering and Applied Sciences, MIT, Sulfur Dioxide

About the author

Steve Hanley Steve writes about the interface between technology and sustainability from his home in Rhode Island and wherever the singularity could lead him. His motto is: "Life is not measured by how many breaths we take, but the number of moments that take our breath away!" You can follow him on Google + and on Twitter.


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