Environment

Antacid for the atmosphere could cool down planet Earth

Could injecting one of the Earth's crust's most abundant compounds into the stratosphere protect against the impacts of global warming?
Could injecting one of the Earth's crust's most abundant compounds into the stratosphere protect against the impacts of global warming?
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Could injecting one of the Earth's crust's most abundant compounds into the stratosphere protect against the impacts of global warming?
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Could injecting one of the Earth's crust's most abundant compounds into the stratosphere protect against the impacts of global warming?

Geoengineering. You might know it as the dastardly scheme to bail out big polluters, a last-ditch effort to save humanity or a needlessly dangerous attempt to intervene in the Earth's natural systems. In any case, swelling CO2 emissions and rising global temperatures mean that plenty of scientists are paying the concept plenty of attention. Among these is a team of Harvard researchers that has discovered a new kind of aerosol it says could be safely introduced into the atmosphere to bounce heat back out into space, and help repair the ozone layer while it's at it.

A variety of seemingly radical ideas fall under the umbrella of geoengineering. In general terms, it means altering the Earth's environment to push back against the impacts of global warming. Spreading iron throughout the ocean to promote growth of carbon-sucking plankton, launching heat-protecting shields into orbit and adding sun-reflective particles to the atmosphere are a few solutions that have been floated.

This final example has gained a fair bit of attention over the last few years, but that's not to say it is without serious drawbacks. The idea is inspired by erupting volcanoes, which spew particles upwards into the stratosphere where they reflect sunlight back into space, temporarily cooling the planet. While these particles soon fall back down to Earth and allow the planet to heat up again, the thinking with so-called solar geoengineering is that this thin layer of reflective sulfate aerosols would be replenished to help keep it cool.

Though this could help solve one crisis, it would likely create another. Once in the stratosphere, these aerosols produce sulfuric acid that erodes the ozone layer, which plays the critical role of soaking up ultraviolet light from the sun to protect us from skin and other cancers. And with the once-depleted ozone now on the mend courtesy of a 30-year global effort, putting it in harm's way once again would hardly be environmentally prudent.

So scientists have been exploring ways to overcome this dilemma with research into nonreactive aerosols that won't eat away at the ozone with such fervor, with a number of alternatives showing some promise. But researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have found success by taking the opposite approach, by investigating aerosols that are highly reactive.

"Anytime you introduce even initially unreactive surfaces into the stratosphere, you get reactions that ultimately result in ozone destruction, as they are coated with sulfuric acid," says Frank Keutsch, co-author of the new study. "Instead of trying to minimize the reactivity of the aerosol, we wanted a material that is highly reactive but in a way that would avoid ozone destruction."

Keutsch and his colleagues knew that the aerosol they were looking for would need to neutralize sulfuric, nitric and hydrochloric acid on its surface, so as to avoid damaging the ozone. By ruling out the unsuitable elements on the periodic table and then through modeling of stratospheric chemistry, the team landed on calcite, a constituent of rocks like limestone, marble and chalk, and one of the Earth's crust's most common compounds.

"Essentially, we ended up with an antacid for the stratosphere," said Keutsch.

The researchers calculated that calcite could not only reflect light into space and cool the planet, but actively repair the ozone layer by neutralizing the acids caused by pollution that kick off harmful chemical reactions. They have started laboratory tests that simulate stratospheric conditions to see if their theory holds up, and emphasize that there are a lot of questions to be answered before such an approach is considered for the real world, and even then, it's unlikely to offer more than a Band-aid-type solution.

"Geoengineering is like taking painkillers," said Keutsch. "When things are really bad, painkillers can help but they don't address the cause of a disease and they may cause more harm than good. We really don't know the effects of geoengineering, but that is why we're doing this research."

The research was published in the Proceedings of the National Academy of Sciences.

Source: Harvard

14 comments
VincentWolf
Pain killers often cause side affects worse than the original pain. For example--vicodin can cause severe constipation in some folks and if they have a bad colon to start with--can kill them.
fb36
Nobody can foresee all side effects of any kind of geoengineering. And not just huge money but you would also need approvals from all countries on Earth. Imagine whenever there is drought or flood in anywhere in the world, people suing US and asking for millions/billions for the damage!
DFrancis
Geoengineering to combat anthropogenic global warming is wreckless and arrogant. The claims of AGW are in doubt by many, too many to ignore, especially as AGW is widely considered to be a political movement not a scientific one. For an example of the pseudoscience of AGW consider the claims that we are approaching an irreversible tipping point. The ice cores prove that just as temperature has varied widely during Earth's history, so too has CO2 concentration. Indeed, there have been periods when CO2 levels have been ten times what they are now. Yet, here we are with a paltry 400 ppm. How can anyone claim that Earth is at an irreversible tipping point when the self-same evidence used by the warmists prove beyond any doubt that nothing about Earth's climate or atmosphere is constant. Geoengineering will be our biggest folly, far worse than leaving the climate to do what it does best on its own.
Rumata
Global warming is a great gift for mankind, because it increases the natural resources of human living: increases the usable area for agriculture and increases corn yields. If we cool down the Earth, millions would start to starve, and wars would be started to access the natural resources. Man-made global warming is a myth, and global warming is a good news for the human race. The development of the whole human civilization was made possible by a global warming 11 thousand years ago.
saveenergy
I agree with D Frances "Geoengineering to combat anthropogenic global warming is wreckless and arrogant" Look at all the mistakes we've made in the past e.g. rabbits & toads in Australia, thalidomide.....the list is endless. As they say 'Sow the wind & reap the whirlwind' Put ( use due diligence on climate org ) into Google for up to date information on the climate.
ChecMate
I agree totally with Rumata ,who is dead on in what is really the whole picture here. It has been discovered that the earth was approximately 18 degrees warmer in the past and this allowed large creatures such as dinosaurs and other reptiles to flourish and grow extremely large. It seems the environmentalists won't be happy until we are under another ice age and a colder climate would be very bad for us, especially northern countries like Russia and Canada.
Lardo
"We really don't know the effects of geoengineering, but that is why we're doing this research. Once we have declared that our theory is sound, we'll put it into practice. After that, if anything should go wrong, we'll simply blame it on the United States (in general) and Republicans in particular. You know... pretty much like we do now when we goof up.]"
Kpar
All these comments are well stated, BRAVO! The idea of introducing a "cure" into a chaotic system of which we know little is bound to have unintended and possibly disastrous results. It seems the height of arrogance to think that we know all we need to know about the Earth's climate, and, as Rumata has clearly stated, just what is the optimum temperature? I am sure our Canadian friends wouldn't mind a little "Global Warming", and, as I sit here hiding from the outside temps of 2C in Chicago, I wouldn't mind it myself...
Douglas Bennett Rogers
Equatorial desserts have high thermal emittance. This is how most of the heat escapes from the Earth. Transpiration of water in arid lands produces about 80% of AGW.
habakak
DFrancis....I agree that geoengineering is a bad option and should be avoided. However, the only people who doubt AGW are non-scientists (in other words most of the people in the world) who are not trained to understand the issue at hand. Like a clerk espousing about the engineering issues of an airplane or skyscraper. However, it does not matter that there were more CO2 (undeniable) in the atmosphere of the earth millions of years ago. The issue is that IF the ice caps of the world melts and sea levels rise, hundreds of millions of people will be left homeless and trillions of real estate and investments were lost. Consider Manhattan getting drowned in 4 feet of water. Everybody in Manhattan would be homeless and almost everybody working in Manhattan would suddenly be without a job. Whether it happens in 1 day or 30 years, the cost and implications are the same. You do not need to be a scientist to understand this. Whether temperatures are rising due to human use of fossil fuels or not (scientific consensus is that it IS - simple math says so - CO2 is a greenhouse gas - humans produce about THIRTY times as much CO2 as is released through natural processes). Where people lose their senses is that this is not about EARTH SURVIVING. It WILL. We might not. Or at least in vastly smaller numbers due to a resource crunch. Think about all the wealth and economic potential getting lost if most of the big coastal cities in the world gets lost due to flooding.
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