Climate Links: 05/26/2017

Stop hoping we can fix climate change by pulling carbon out of the air, scientists warn. Chelsea Harvey, WashPo. May 22, 2017.

Scientists are expressing increasing skepticism that we’re going to be able to get out of the climate change mess by relying on a variety of large-scale land-use and technical solutions that have been not only proposed but often relied upon in scientific calculations.

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The solution that’s been proposed in numerous reports and climate models, including those released over the years by the Intergovernmental Panel on Climate Change (IPCC), is a technology known as bioenergy and carbon capture and storage, or BECCS. This strategy involves establishing large plantations of fast-growing trees, capable of storing large quantities of carbon, which can then be harvested and used for fuel. Biomass burning facilities would need to be outfitted with a special carbon-capturing technology, which would capture the carbon dioxide produced and store it safely away, potentially in geological formations deep underground. 

It’s an ambitious proposal, and one that many scientists have pointed out is nowhere near the point of becoming feasible, even from a technological perspective.

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Worryingly, they add, carbon dioxide removal is increasingly assumed by climate models and planning tools as a future mitigation tactic. While they encourage continued research and development of the technology, the authors also urge the necessity of “avoiding cavalier assumptions of future technological breakthroughs.”

Scientists puzzled by slowing of Atlantic conveyor belt, warn of abrupt climate change. Mike Gaworecki, Mongabay. May 27, 2017.

These currents are known as the Atlantic Meridional Overturning Circulation (AMOC) — or, more popularly, “the Atlantic conveyor belt” — and they have “mysteriously” slowed down over the past decade, according to Eric Hand, author of a Science article published this month. 

Scientists are increasingly warning of the potential that a shutdown, or even significant slowdown, of the Atlantic conveyor belt could lead to abrupt climate change, a shift in Earth’s climate that can occur within as short a timeframe as a decade but persist for decades or centuries.

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As far back as 2003, Robert Gagosian, who was then the President and Director of the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts (he’s now President Emeritus), warned that we ignore the threat of abrupt climate change induced by a slowing or shutdown of the AMOC at our own peril. 

“[T]he debate on global change has largely failed to factor in the inherently chaotic, sensitively balanced, and threshold-laden nature of Earth’s climate system and the increased likelihood of abrupt climate change,” he wrote in a post on the WHOI website.

Waves rippled through Greenland's ice. That's ominous. Brian Kahn, Climate Central. May 26, 2017.



Researchers Race to Understand Black Carbon’s Impact on Thawing Tundra. Madeline Ostrander, Arctic Deeply. May 22, 2017.

Black carbon is a product of incomplete combustion from forest fires and the burning of both wood and fossil fuels, and its influence on the Arctic is like the proverbial death by a thousand cuts. At the top of the world, black carbon can land on snow and ice, darkening them, which makes them soak up more heat from the sun and melt faster. It can also absorb and radiate heat from sunlight as it floats through the atmosphere. Black carbon may be worsening the extreme warming felt all over the Arctic, record temperatures that are making permafrost disintegrate and sea ice melt. And if the Arctic gets too much warmer, it is, in the long term, like setting off a giant Rube Goldberg machine – once Arctic ice melts, seas rise; ocean waters absorb more heat; methane, another potent greenhouse gas, escapes from the permafrost.

Arctic sea ice report: PIOMAS May 2017. Arctic Sea Ice Blog. May 4, 2017.