[MCN] Positive climate feedbacks may shove the young into murderous conditions

[Lance Olsen]

Extended excerpt : Once upon a time, the major cause for worry about a 
hotter planet was the carbon we routinely dump to the atmosphere thanks 
to daily combustion of fossil fuels. The dumping has turned the atmosphere 
into a better and better heat trap, and the heat we’ve already trapped in ocean 
and atmosphere has already become a powerful player over our lives and times. 

Obviously enough, this familiar level of heat was already going to cause trouble, including real risk of pushing us out past danger points of 1.5 and even 2C hotter than before the fossil fuels era. But our routine dumping has been getting even more dangerous to life, liberty, happiness and capital wealth because it’s been inviting some muscular new kids to the block.

The new kids are seriously threatening to kick the heat to new heights on their own, independent of anything we do.

The new kids have a name – positive feedbacks. Although the series of IPCC assessments have given them scant mention, science has known of their implications since the 1890s. 

Back then, the world had already begun burning coal at scale, it was already understood that burning the stuff added CO2 over and above what was already normal to the atmosphere. And, by 1860, it had already been established that CO2 is a heat-trapping gas. So, using the crudest, simplest model in the history of climate science, physical chemist Svante Arrhenius was able to predict in 1896 that increasing combustion would one day heat the world enough to force a loss of snow and ice. 

Arrhenius also knew that snow and ice reflect incoming solar radiation away from Earth, with a cooling effect called albedo. So, taking his analysis a next logical step, he expected that loss of albedo would increase Earth’s heat above and beyond the heat trapped by CO2, and would continue to heat the world on its own. 

This was the world’s first glimpse into positive feedbacks. It wasn’t the last. We now have a virtual gang of them at the door, and the language of climate emergency has been gaining traction far and wide, in Australia, Canada, the UK, and the US.

A journalist, Mark Lynas was the first to take multiple positive feedbacks seriously. Lynas devoted a book to setting out their clout. In his book, Six Degrees, Lynas describes a series of positive feedbacks that could force the world to get hotter, then hotter, then hotter yet, even if humans quit burning fossil fuels. 

For example, Lynas cited the scientific record of evidence that the Amazon forest is at risk of dieoff from the same heating that endangers ice and snow. The scientific community had expressed concern that a collapse of the vast Amazon forest would have global consequences from the dying forest’s release of carbon to the atmosphere. 

Lynas took that analysis to a next step, pointing out that the new dose of heat from a dying Amazon could force a thawing of permafrost, melting its ice, and setting its own carbon free to force the planet into even greater heat, thanks to one positive feedback setting the stage for another.

Sketching out the plausible consequences of serial positive feedbacks, Lynas argued that we could kick this process into gear if we if we fail to halt the heat at 2C above the advent of the fossil fuels era. His analysis pointed to an increase of heat to 6C, and “mass extinction.”

At the time, climate scientist Eric Steig remarked that, if what he read about Lynas’ book in the newspapers was true, it was probably alarmist and not worth reading. 

Lynas asked Steig to read it himself, so he did. After reading it, Steig said, “Mark Lynas <http://www.marklynas.org/> will no doubt be pleased that I very much like the book. To be sure, it is alarming, but the question of whether it is alarmist is a more difficult one.” Steig went on to say, “all climate scientists (particularly those that talk to the public) ought to read this book <https://www.amazon.com/exec/obidos/ASIN/%201426203853/counterpunchmaga>.”

Nine years later, in an article published by the Proceedings of the National Academy of Sciences, <https://www.pnas.org/content/115/33/8252> the scientific community had also taken multiple positive feedbacks seriously. Without mentioning Lynas’ earlier work, the scientist authors considered how these feedbacks can hit in a series, like dominoes in a row, falling, one after another, forcing the heat higher, then higher, then higher yet, even if humans quit burning fossil fuels. Where Lynas saw risk of heat rising by about 6C, the scientists concluded that we could kick the heat higher by about 5C.

The scientists identified 15 positive feedbacks that could set the world on a trajectory toward a “Hothouse Earth”. Like Lynas, they concluded that we could kick this process into gear if we fail to halt the heat at 2C above the advent of the fossil fuels era. 

Getting a 2C warming, they say, could set the planet on a trajectory that “would likely cause serious disruptions to ecosystems, society, and economies.” They concluded that avoiding two Celsius would require, among other things, “behavioral changes” and “transformed social values.”

Authors of the Hothouse Earth analysis could have added an 16th feedback from the heat added to oceans. Our dependency on fossil fuels has turned up the heat in the oceans, so that they can now evaporate — e-vapor-ate — more freely into the atmosphere above. Six years before the Hothouse Earth article, an article in the Journal of Geophysical Research <ttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011JD017421> had reported that, “water vapor is the most abundant greenhouse gas,” in the atmosphere, and that atmospheric heat could be forced even higher “through water vapor feedback.”

Even without an 16th positive feedback from the ocean, Hothouse Earth co-author Hans Joachim Schellnhuber <https://www.commondreams.org/news/2018/12/13/after-30-years-studying-climate-scientist-declares-ive-never-been-worried-i-am-today?> has said the language of global warming “doesn’t capture the scale of destruction.”

Much the same concern about the language we use to describe the rise of heat had already been expressed in an assessment by Harvard’s John A. Paulson School of Engineering and Applied Sciences; “For decades, we called it ‘global warming,’ an innocuous-sounding phrase invoking a gentle increase in worldwide temperatures, like turning up the thermostat in a house.

“People asked, so the climate is getting warmer. Who cares?” said Michael B. McElroy, the Gilbert Butler Professor of Environmental Studies <https://www.seas.harvard.edu/directory/mbm> at Harvard University. “And scientists are partly to blame for that because of how we’ve described climate change.” 

Climate science has been struggling with this issue for years.

For example, in its October 13 2006 issue, Science quoted researcher Brian O’Neill’s concern that the IPCC reports don’t convey the full range of risks; “the extreme scenarios that tend to fall out of the IPCC process may be exactly the ones we should most worry about.”

In that same issue, Science quoted Michael Schlesinger, a climate scientist at the University of Illinois, Urbana- Champaign. Schlesinger remarked that, “Things are happening right now with the ice sheets that were not predicted to happen until 2100. My worry is that we may have passed the window of opportunity where learning is still useful.” 

Science returned to these concerns in June, 2007, quoting climate researcher Stefan Rahmstorf’s comment that, “The IPCC has been overly cautious in not wanting to give any large number to [future] sea-level rise.” Reporting that “Scientists are still trying to strike a balance between their habitual caution and growing concern over uncertain but disastrous greenhouse outcomes,” Science also quoted glaciologist Robert Thomas’ remark that, “ ‘Most scientists don’t want to, but I think we need a way to explore’ the extreme end of the range of possibilities.” Thomas told Science that  scientists need “a better way” than IPCC’s consensus approach, “so we can communicate with the public without becoming scaremongers.”

None of this can or should be taken as an excuse to blame what James Hansen has called “reticent’ scientists for the climate predicaments we face today. Actually, even their cautious warnings have been attacked by titans and toadies of the fossil fuel industry in the grossest and most scaremongering ways. Their attacks have so mortified so many that researchers including America’s Michael Mann and Canada’s Andrew Weaver have been targeted with death threats <https://www.theguardian.com/science/2012/mar/03/michael-mann-climate-change-deniers>.

For a wide variety of reasons then, today’s CO2 levels have already opened the door to the muscular new extremes of heat we’ll get from 15 or more positive feedbacks. Because the CO2 from our fossil fuel economy remains in the atmosphere for centuries, the open door for positive feedbacks won’t be closing anytime soon, and the risk of global emergency looms large unless we overcome the normal human resistance to change.

The extent of heat we’ll get from the growing gang of positive feedbacks depends a lot on how we spend our time and money. Just as the Hothouse Earth authors suggested, individual behavior and broader social values come into focus. 

In May, 2018, the journal Nature Climate Climate <https://doi.org/10.1038/s41558-018-0155-4> reported that “”The big challenge is still to deliver emissions reductions at the pace and scale needed, especially in a world where economies are driven by consumption.”

While there’s all the complexity anyone could want in our consumption’s power to force the heat to increasingly dangerous levels, at least three things are glaringly clear. First, the American and other major economics are driven by consumption. In the US, consumer spending props up about two-thirds of the national economy <https://www.reuters.com/article/us-usa-economy-retail/u-s-consumer-spending-strengthening-in-boost-to-economy-idUSKBN1OD1M2>.

Obviously enough then, any suggestion that consumers pull back on spending will immediately trigger cries that the economic skies will fall. Frugality is damned as  calamity.

Complete article here 
<<https://www.counterpunch.org/2019/02/14/heat-and-the-end-of-the-world-as-we-know-it/ <https://www.counterpunch.org/2019/02/14/heat-and-the-end-of-the-world-as-we-know-it/>>>

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