So the short version, as I best have understood it is that research was done on what triggered natural warming and cooling cycles in the the distant past on earth. One of the areas of interest was that there was a tipping point where a slight warming period became a "hot period" where rapid changes in temperatures occurred (rapid in geological time.)
The 2 main culprits as we can best understand it is the frozen methane in the oceans which will release after further ocean warming (100-250yrs?), and the permafrost which contains a lot of carbon and of course patches of methane kept safely frozen underground in pockets of methane.
This article from last year covers a few of the key points:
Quote:
The data is important for climate change models, since the emissions released by thawing permafrost could significantly affect levels of greenhouse gases in the atmosphere. Old carbon isn't part of that equation if it remains trapped in frozen soil, but it's released as methane and carbon dioxide when permafrost soils thaw and decompose.
Walter Anthony said the billions of tons of carbon stored in permafrost are about twice the amount that is currently in the atmosphere. Many researchers are concerned that if old carbon begins to cycle it could create a feedback loop—its emissions contribute to warming, which again contributes to the thawing of more permafrost.
"If you open the freezer door, you thaw permafrost soil that's been frozen for a long time, and the organic matter in it is decomposed by microbes," Walter Anthony said.
Grosse, a co-author of the study from the German Alfred Wegener Institute, said climate change researchers are increasingly concerned about how fast that thaw and release of carbon may happen, and whether the process has already accelerated in recent years.
The new study found the rate of old carbon released during the past 60 years to be relatively small. Model projections conducted by other studies expect much higher carbon release rates—from 100 to 900 times greater—for its release during the upcoming 90 years. This suggests that current rates are still well below what may lay ahead in the future of a warmer Arctic.
Read more at: https://phys.org/news/2016-08-methan...frost.html#jCp
|
So the key note is a lot of the science is pretty settled with the data we have on current projects of warming in the next 50-100 years based on the data inputs we are pretty confident in at this point.
The one that can really kick the already lighting speed at which we are warming is of course how this all plays out with the permafrost and the methane release which I have read some scientists speak of with doomsday like fear if we start to see significant thawing of the permafrost.
The problem as we all know isn't that the earth hasn't had this type of PPM of C02 in the atmosphere that's predicted in the next 100 years, but at the rate at which the change is occurring, this is why we are seeing species dying out at rarely seen in earths history and is being dubbed a great extinction period by scientists today.
The fact we have so much frozen methane, which is about 19 times more harmful as a warming agent than c02, means we have to treat even small changes with great concern.
The runaway warming which is currently not in the climate models, but many think we should consider altering to show what this would look like IF we started to see significant release of c02 and methane in the next 50 years which many are fearing.