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Climate Change Geoengineering study

Published on November 9th, 2017 | by Steve Hanley


New Computer Modeling Helps Scientists Analyze The Effects Of Geoengineering

November 9th, 2017 by  

On June 15, 1991, Mount Pinatubo in the Philippines erupted, spewing millions of tons of volcanic ash and gases such as sulfur dioxide into the atmosphere. For years afterward, parts of the Earth experienced cooler than normal temperatures, partly because when sulfur dioxide interacts with sunlight, it forms tiny particles called aerosols that partially block the rays of the sun. It was the most recent experiment in geoengineering, albeit an unintentional one.

Geoengineering study

The simulations on the left represent how global temperatures are expected to change if greenhouse gas emissions continue on a “business as usual” trajectory. The simulations on the right show how temperature could be stabilized in a model by injecting sulfur dioxide high into the atmosphere at four separate locations. Because greenhouse gases are being emitted at the same rate in the simulations on the left and the right, stopping geoengineering would result in a drastic spike in global temperatures. Credit: Copyright NCAR

In a study funded by DARPA and the National Science Foundation, scientists at the National Center for Atmospheric Research, the Pacific Northwest National Laboratory, and Cornell University have developed a highly sophisticated atmospheric computer model that helps them understand how the sulfur dioxide from Mount Pinatubo  interacted with earth’s atmosphere.

In a new report published in the Journal of Geophysical Research — Atmospheres, the scientists say the new model is better able to predict what the effects on global temperatures might be if large quantities of sulfur dioxide were injected into the upper atmosphere deliberately. The results suggest the average temperature of the earth could be kept at 2020 levels (we’re not quite there yet, obviously) even if humanity follows a “business as usual” approach to limiting carbon emissions.

Oh, happy day. Thanks to geoengineering, we could burn all the oil and coal we want and not have to worry about earth temperatures rising to the point where we all have to become subsistence farmers in Antarctica in order to survive. We could continue to drive 7,000 pound V-8 powered behemoths to work and put people back to work mining coal to power our utility grid. Humanity would be saved and all those who believe we will somehow find a way to “science our way” out of global warming would be proven right.

So what is it the scientists did, exactly? They developed new algorithms that allowed them to determine where sulfur dioxide injections should take place and in what amounts with far greater precision than previously possible. Prior computer modeling asked if geoengineering was feasible at all. It began by assuming sulfur dioxide injections would be done at the Equator. Those studies showed equatorial areas would cool too much while areas further toward the poles would not cool enough to prevent massive climate changes. Global temperature rise is not uniform. For instance, temperatures in the northern hemisphere are rising faster than in the southern hemisphere. How to balance things out?

The researchers used their techniques to study 14 possible injection sites at seven different latitudes and two different altitudes — something never before tried in geoengineering research. They found that they could spread the cooling more evenly across the globe by choosing injection sites on either side of the equator and adjust for differences in warming between the hemispheres.

“The results demonstrate that it is possible to flip the research question that’s been guiding geoengineering studies and not just explore what geoengineering does but see it as a design problem,” says Doug MacMartin, a scientist at Cornell and the California Institute of Technology. “When we see it in that light, we can then start to develop a strategy for how to meet society’s objectives.”

Wait a minute, folks. Gaining a better understanding of how high altitude injections help keep the earth from overheating may be useful information. But there is a huge difference between macro effects and micro effects. High altitude atmospheric changes could lead to less rainfall and thus famine in some parts of the world. If Bangladesh is disadvantaged, that is one thing, but if the great agricultural regions of the United States turn into modern day dust bowls, that is quite a different kettle of fish. The ethical and political ramifications may be far more difficult to predict than upper level winds in the atmosphere.

“This is a major milestone and offers promise of what might be possible in the future,” said NCAR scientist Yaga Richter. “But it is just the beginning; there is a lot more research that needs to be done.” Ben Kravitz is a scientist at PNNL. “For decision makers to accurately weigh the pros and cons of geoengineering against those of human-caused climate change, they need more information,” he says. “Our goal is to better understand what geoengineering can do — and what it cannot.”

“It was critical for this study that our model be able to accurately capture the chemistry in the atmosphere so we could understand how quickly sulfur dioxide would be converted into aerosols and how long those aerosols would stick around,” says NCAR scientist Michael Mills. “Most global climate models do not include this interactive atmospheric chemistry.”

So how much sulfur dioxide are we talking about here? The scientists calculate that by the end of this century, we would need to add the equivalent of five times the amount that spewed out of Mount Pinatubo back in 1991. In addition to high altitude injections, localized injections would be needed to counteract droughts or flooding around the world.

The researchers are already studying ways to further improve their algorithms to increase the accuracy of their predictions. “We are still a long way from understanding all the interactions in the climate system that could be triggered by geoengineering, which means we don’t yet understand the full range of possible side effects,” said NCAR scientist Simone Tilmes. “But climate change also poses risks. Continuing research into geoengineering is critical to assess benefits and side effects and to inform decision makers and society.”

And what might some of those risks be? None of the scientists have drawn the connection between sulfur dioxide and human health. Those aerosols that could block some of the sun’s rays to cool the earth are also know to the medical community as fine particulates — tiny orbs that are less than 2.5 microns in diameter. They are so small they can cross directly into the bloodstream in the lungs and lead to pulmonary and cardiovascular disease. A study out this week claims fine particulates are responsible for more than 10 million cases of kidney disease each year.

And people want to pump billions of pounds of the stuff into the upper atmosphere so it can find its way into the lungs of all living things just so the global economy can continue doing “business as usual”? No wonder Michael Mann entitled his latest book The Madhouse Effect. To save the fossil fuel industry, we should subject ourselves to enormous health risks? This is a joke, right?

This is the point at which people with an IQ higher than a turnip should begin pondering the historical results of fiddling with nature. Some people call it the Law Of Unintended Consequences. Look up rabbits in Australia or kudzu on Google for an example of how this stuff usually works. Sometimes the cure can be worse than the disease, although in this case both are terminal as far as humanity is concerned. Common sense would suggest severely reducing carbon emissions is the best answer, but that would have a negative effect on corporate profits and we can’t have that, now can we?

Source: NCAR

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About the Author

writes about the interface between technology and sustainability from his home in Rhode Island. You can follow him on Google + and on Twitter. "There may be times when we are powerless to prevent injustice, but there must never be a time when we fail to protest." Elie Wiesel

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