Guest essay by Eric Worrall
h/t Dr. Willie Soon; A pair of researchers from the Norwegian Business School have produced a climate prognosis so profoundly depressing even Katharine Hayhoe has publicly complained about it.
Just Stopping Emissions May No Longer Be Enough to Stop Global Warming
Researchers argue that it’s time to invest in aggressive carbon capture
Earlier this year, the Earth saw a huge dip in carbon emissions as nations around the globe locked down to slow the spread of the coronavirus. It offered a glimpse into what the world might look like if we took drastic steps to reduce our carbon emissions to slow the spread of global warming: For a brief moment, smog-choked cities around the world had clear skies.
But according to a new modeling study published in Scientific Reports today, even if we made such drastic reductions permanent, it would still not be enough. The study suggests that if we stopped all human-made greenhouse gas emissions immediately, the Earth’s temperatures would continue to rise because of self-sustaining melting ice and permafrost. These “feedback loops” — in which melting ice causes less sunlight to be reflected back into space, which in turn raises temperatures and causes more ice melt — have already been set into motion, the researchers argue.
Humanity “is beyond the point-of-no-return when it comes to halt the melting of the permafrost using greenhouse gas cuts as the single tool,” Jørgen Randers, PhD, professor emeritus of climate strategy at BI Norwegian Business School and lead author of the study, tells Future Human in an email. That’s not to say we should give up on reducing emissions: Rather, Randers says that the world “should accelerate its effort to cut greenhouse gas emissions (in order to postpone as much as possible the temperature rise) and start developing the technologies for large scale removal of greenhouse gases from the atmosphere.”
The abstract of the study;
An earth system model shows self-sustained melting of permafrost even if all man-made GHG emissions stop in 2020
The risk of points-of-no-return, which, once surpassed lock the world into new dynamics, have been discussed for decades. Recently, there have been warnings that some of these tipping points are coming closer and are too dangerous to be disregarded. In this paper we report that in the ESCIMO climate model the world is already past a point-of-no-return for global warming. In ESCIMO we observe self-sustained melting of the permafrost for hundreds of years, even if global society stops all emissions of man-made GHGs immediately. We encourage other model builders to explore our discovery in their (bigger) models, and report on their findings. The melting (in ESCIMO) is the result of a continuing self-sustained rise in the global temperature. This warming is the combined effect of three physical processes: (1) declining surface albedo (driven by melting of the Arctic ice cover), (2) increasing amounts of water vapour in the atmosphere (driven by higher temperatures), and (3) changes in the concentrations of the GHG in the atmosphere (driven by the absorption of CO2 in biomass and oceans, and emission of carbon (CH4 and CO2) from melting permafrost). This self-sustained, in the sense of no further GHG emissions, melting process (in ESCIMO) is a causally determined, physical process that evolves over time. It starts with the man-made warming up to the 1950s, leading to a rise in the amount of water vapour in the atmosphere—further lifting the temperature, causing increasing release of carbon from melting permafrost, and simultaneously a decline in the surface albedo as the ice and snow covers melts. To stop the self-sustained warming in ESCIMO, enormous amounts of CO2 have to be extracted from the atmosphere.
Why was Hayhoe so upset about a climate study which says we’re all doomed?
It appears that people have to think climate change is enough of a problem to be motivated to act, but if the message is too depressing, supporters could lose interest and lapse into apathy.
via Watts Up With That?
November 13, 2020 at 04:17AM