Positive Feedbacks

Just to keep you up to date.

According to Guy McPherson’s reckoning, we are up to 49 positive feedbacks. Here is are some of the more recent discovered

Positive Feedbacks - 

update

http://guymcpherson.com/2014/01/climate-change-summary-and-update/

40. “During the last glacial termination, the upwelling strength of the southern polar limb of the Atlantic Meridional Overturning Circulation varied, changing the ventilation and stratification of the high-latitude Southern Ocean. During the same period, at least two phases of abrupt global sea-level rise—meltwater pulses—took place.” In other words, when the ocean around Antarctica became more stratified, or layered, warm water at depth melted the ice sheet faster than when the ocean was less stratified. (Nature Communications, 29 September 2014)

41. “Open oceans are much less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum. This means that the Arctic Ocean traps much of the energy in far-infrared radiation, a previously unknown phenomenon that is likely contributing to the warming of the polar climate.” (Proceedings of the National Academy of Sciences, November 2014)

** 42. Dark snow is no longer restricted to Greenland. Rather, it’s come to much of the northern hemisphere, as reported in the 25 November 2014 issue of the Journal of Geophysical Research. Eric Holthaus’s description of this phenomenon in the 13 January 2015 edition of Slate includes a quote from one of the scientists involved in the research project: “The climate models need to be adding in a process they don’t currently have, because that stuff in the atmosphere is having a big climate effect.” In other words, as with the other major self-reinforcing feedback loops, dark snow is not included in contemporary models. **

43. The “representation of stratospheric ozone in climate models can have a first-order impact on estimates of effective climate sensitivity.” (Nature Climate Change, December 2014)

44. “While scientists believe that global warming will release methane from gas hydrates worldwide, most of the current focus has been on deposits in the Arctic. This paper estimates that from 1970 to 2013, some 4 million metric tons of methane has been released from hydrate decomposition off Washington [state]. That’s an amount each year equal to the methane from natural gas released in the 2010 Deepwater Horizon blowout off the coast of Louisiana, and 500 times the rate at which methane is naturally released from the seafloor.” (Geophysical Research Letters, online version 5 December 2014)

45. “An increase in human-made carbon dioxide in the atmosphere could initiate a chain reaction between plants and microorganisms that would unsettle one of the largest carbon reservoirs on the planet — soil” (Nature Climate Change, December 2014 )

** 46. Increased temperature of the ocean contributes to reduced storage of carbon dioxide. “Results suggest that predicted future increases in ocean temperature will result in reduced CO2 storage by the oceans” (Proceedings of the National Academy of Sciences, January 2015) **

** 47. According to a paper in the 19 January 2015 issue of Nature Geoscience, melting glaciers contribute subsantial carbon to the atmosphere, with “approximately 13% of the annual flux of glacier dissolved organic carbon is a result of glacier mass loss. These losses are expected to accelerate.” **