These are both consequences and causes of further GW. (If mods want to shift this to the Science section, that's fine.) I have been trying to assemble as complete as possible a list of climate feedbacks as I have come across them over the years. This is a brief list, without citations attached, but I could supply those easily in most cases if anyone is interested.
I would love to hear people's comments, additions, critiques...Obviously some of these are both more major and more certain than others. Ultimately it would be good to try to rank them, but that difficulte (impossible?) task will have to wait. For now I just want to know if I am missing any major ones, or if people think any I have here are completely off (or wrong sign!).
“Positive”--exacerbatingcharney = “fast” feedbacks:
--albedo change with loss of land and sea ice and snow (stops when all snow and ice gone)
--water vapor
--cloud (both ways?)
--lapse rate (though this may also cut both ways?)
non-charney “slow” feedbacks:
carbon feedbacks--forests, grasslands, peat dry up and burn/die>CO2
--“ “ get bugs/diseases, die>termites>methane; die>burn
--soils, already weakened from above, wash away with increasingly extreme downpours, leaving no medium for plant that could absorb CO2 to grow
--terrestrial soils dry up>CO2 methane “If the bank of carbon held in the world’s soils were to drop by just 0.3 percent, the release would equal a year’s worth of fossil fuel emissions”
--permafrost melts—release CO2&methane from new bacterial activity/ free methane from deeper reservoirs, starts to (net) release rather than absorb (sink) C
--melting Greenland and Antarctic icecap uncovers same
--feedback combo: Each extreme weather event leads to less CO2 absorption, leads to more warming, leads to more extreme weather events, leads to....
--sea bed permafrost, clathrates, free methane
--sea surface increased activity of methanogens
--newly flooded areas from sea level rise become new swamps—more methane
--as atmospheric humidity increases with global warming, the amount of high troposphere ice particles will increase, and as these ice particles generally serve to reduce the rate of methane oxidation; this implies that with increasing global warming, the global warming potential, GWP, of the methane in the atmosphere over the Antarctic will increase.
--Rising CO2 In Atmosphere Also Speeds Carbon Loss From Forest Soils
--newly ice-free Arctic ocean erodes islands and coastlines releasing carbon in soils
--warming ice encourages dark cryophilic bacteria which alters albedo
--Trees excude CO2 rather than taking it in
--Sudden switch from a three cell NoHem system to a one cell system because of loss of temp differential between equator and No Pole. One cell will transport heat from equator to pole much more efficiently.
--if methane reaches a big enough level in the atmosphere, its average time aloft starts going up, because saturation point is reached to where there's not enough OH around in the atmosphere so that methane can be split apart that way
--warmer ocean absorbs less CO2
--warmer oceans kill phytoplankton that otherwise sequester CO2
--draw downs behind damns during (CC induced) droughts increases methane release
Other:
--drought, an expected outcome of GW, can increase intensity of heatwaves
--end of change of state--when all ice gone in a region, no more heat sucked up by its melting
--newly open Arctic Ocean evaporates more H2O (a GHG) (but open ocean can also absorb more CO2)
-- Stripping of Oxygen from the Oceans
--melting permafrost releases NOX
--accelerating albedo shift with black carbon (soot) concentrating on surface as melt goes on
--accelerating albedo shift with more trees growing in the tundra; now happening faster than once thought, since many ‘shrubs’ native to and widespread throughout the tundra grow into trees as conditions warm
--uplift from isostatic rebound as Gr icesheet melts changes angle to greater slope down which ice slides faster
--similar activity could cause local earthquakes which may increase collapse of fragile ice
--Loss of GIS accelerating as highest areas melt down to lower, warmer areas, not only increasing sea level (see above), but also hastening the time when there will be no more ice cap to absorb hundreds of quintillions of joules of energy as it melts (see above)
--More wild fires also means more soot in the air which further changes albedo of ice and snow, leading further to the effects mentioned immediately above
-- Bigger storms from GW cause updrafts to carry moisture all the way into the stratosphere, reducing ozone and creating more ghg (water vapor) into part of the atmosphere that has very little of it.
--Hadley cells shift "so that air is being pulled along the earths surface from mid latitudes towards the Arctic... more soot and dust will accumulate on the remaining ice including on Greenland."
--Reversal of the Polar Vortex
"Putting together the above information, we see what powers the polar vortex. As the Arctic air radiates heat into space, it sinks, sucking high altitude air toward the poles. Coriolis effect skews this flow of air to the right so at high latitudes, on the surface of the earth there are North East winds (flowing towards the South West). With more and more heat being absorbed by an ice free Arctic ocean and transmitted to the air, this circulation pattern should reverse. This would be expected to bring a huge flux of warm air from the south which would exacerbate the effect and cause sudden extremely warmer conditions in the Arctic for the months in question. These will be South West winds (flowing toward the North East)”
--As beetles and other diseases move north aided by GW, the number of sick trees increases rapidly. The levels of methane these emit can be high enough to ignite
-- mixing has an immediate effect upon ice through churning rather than the longer term greenhouse effects from bubbling methane, which of course opens up more water which, through albedo, warms up the water, which radiates down to liberate more methane…
--Loss of GIS and other ice sheets (as well as other shifts in water on land –drying and flooding…) lead to tectonic shifts and increased eruptions of volcanoes—releasing carbon that leads to likely longer-term warming (though their aerosols and other particles will lead to a temporary cooling).
--Oceans that grow more acidic through Man's fossil fuel burning emissions, can amplify global warming by releasing less of a gas that helps shield Earth from radiation
http://phys.org/news/2013-08-science-global-source-sea.html (Thanks to johnm33 for just posting this one on the science thread, though as ccg points out, it is unclear if they are talking about direct aerosol shielding, or about increased cloud formation.)
Human responses:
--war
--AC
--denial
--geo—engineering attempts gone bad
--more and more people moving to avoid consequences of GW—refugees, both burning oil to move and burning ff to build new cities…
--more and more ff-fueled infrastructure built (sea walls, etc) to stave off effects of GW…
--aerosol—as we turn away from coal in response to GW (and clean up aerosol pollution from those that remain), the ‘aerosol parasol’ goes away causing and essentially immediate global temp increase of .5 – 2 degrees C. (see below)
--rush to ever dirtier sources with lower EROEI—tar sands, low grade coal, deepwater oil…
--Rivers dry, barges can’t haul material—more sent by more ff intensive truck and rail
--newly ice-free Arctic leads/has lead to more ff extraction/burning as well as new oil spills, and perhaps activity that further accelerates methane hydrate (and other methane) release
Negative (=damping) Feedbacks (and related dynamics)
--black body radiation ^4, Planck and all that
--clouds (?)
--weathering of rock, mountains; the reaction SiO3 + CO2 > CaCO3 + SiO2 (?) runs faster in a warmer climate (but this effect is limited by the amount of exposed rock available, so it is a very slow feedback)
--ocean absorption
--same enhanced in Arctic by loss of sea ice
--a more ice-free Arctic may directly absorb more CO2 into its waters
--desertification alters albedo so more light reflected into space(?)
--increased biological activity in warming permafrost and tundra (overwhelmed by other factors?)
--lapse rate--as heat and moisture get distributed more evenly through the whole air column, it can more easily be radiated into space (help needed here)
--Loss of GIS and other ice sheets (as well as other shifts in water on land –drying and flooding…) lead to tectonic shifts and increased eruptions of volcanoes—whose aerosols and other particles will lead to a (temporary) cooling (but likely longer-term warming).
----flooding and deepening of continental shelves increases the activity of the ‘continental shelf pump’ which moves particulate carbon off of the shelf (where it might eventually get back into the atmosphere) down into the deep sea, where it is likely to remain for a very long time.
--SLR increases pressure on subsea clathrates keeping them stable (but not as fast as ocean temperatures increase?)
--some plants growing faster with increased atmospheric CO2 (overwhelmed by predominantly negative effects of GW on plant growth?)
Human response(??)
--as major impacts kick in, global PTB or general population wakes up and drastically decrease ff burning...(dream on)
--planting native grasses in mid latitudes, trees in tropics, terra-preta (?)
--geo-engineering (very likely to very wrong—best in other side)
--eating less meat, traveling less (esp by plane), consuming less, make fewer babies…
--alt energy, because of promotion through policy, economic tipping points, or a combination, rapidly replace nearly all ffs (are we seeing the beginnings of this??)
--major breakthroughs in C sequestration technology that can be rapidly built out with minimal use of ff (but this could prompt 'moral hazard' behavior, and in any case seems rather a techno-fantasy than an even remote likelihood)
--revolution (could go either way?)
--grimmer—gw leads to widespread shortages of basic food supplies—mass starvation, fewer using ff-powered machines…; econ collapse…same (BUT economic collapse also could lead to big drop in coal plant emissions—good in the long run, but in the short run, this would quickly bring down aerosol emissions. Aerosols have been working as a “parasol,” blocking sunlight from entering the lower troposphere, so keeping us perhaps 2 degrees C cooler. So with this removed, we could see a sudden increase of 2 degrees, which could set off other positive feedbacks discussed above.)
.........................
Please add more of your own in any category (or create a new category!?), or critique any of the above.
--
--
