Permafrost: The Tipping Time Bomb

Permafrost

How much warming would be needed for there to be significant effects on ecosystems and for a significant amount of greenhouse gasses to be released and affect the carbon cycle?

We’re seeing significant amount of thaw already, at least in the Northern Hemisphere. The areas of thawing permafrost are increasing and the southernmost boundaries between continuous and discontinuous permafrost are moving northward as well as the southernmost boundaries of discontinuous permafrost.

As far as ecosystems are concerned, we’ve been seeing a change in hydrology, which has a significant impact on ecosystems locally. The availability of water to a given ecosystem is a major factor that determines which flora and fauna can live there. Depending on the soil, topography, and drainage conditions, the soil can either become waterlogged as the permafrost thaws, or the soil can dry out as the water above the thawing permafrost drains away. We’ve seen both situations happening already: boreal forests are either turning into bogs, swamps or wetlands when there’s too much water (for example in the Tanana Flats near Fairbanks, Alaska), or they are turning into grasslands or steppe-like ecosystems when conditions become too dry (examples can be found in Mongolia or in East Siberia).

As for effects on the carbon cycle and the release of greenhouse gasses into the atmosphere, we’re already seeing significant impacts from this. Several groups of scientists have been having a look at this (including papers by Ted Schuur et al which was published in 2009, as well as papers by Sergey Zimov and Katie Walter), and we have evidence that thawing permafrost is releasing at least carbon dioxide and possibly also methane to the atmosphere. We’re seeing this even with the very moderate degradation of permafrost that’s happening right now.

All climate models predict average temperatures to be warmer by the middle to the end of the 21st century, and permafrost projections show that by the end of the century, at least half of the recently stable permafrost area will experience some degree of degradation. So it means that the thawing of permafrost will become much more common than it is right now as the century progresses, and we’ll likely start seeing a significant and noticeable impact of thawing permafrost on the carbon cycle.

Vladimir Romanovsky on the Current State of Permafrost

HT The Cost of Energy via twitter

Lou has a post you should read
Earth: Ground zero for the permafrost bomb

Melting of the Arctic 'will accelerate climate change within 20 years'

A study into the speed at which the permafrost is melting suggests that the tipping point will occur between 2020 and 2030 and will mark the point at which the Arctic turns from being a net "sink" for carbon dioxide into an overall source that will accelerate global warming, they said.

Melting of the Arctic 'will accelerate climate change within 20 years'


HT WarmingGlobe via twitter

The Sometimes Frost

The Sometimes Frost audio at Living on Earth

GELLERMAN: So what has to be done is we gotta make even greater cuts than are now being voluntarily agreed upon.


Large chunks of soil collapse as a result of permafrost thaw and erosion, as this image taken along the Sagavanirktok River on the North Slope of Alaska near Deadhorse shows. (Photo: Kevin Schaefer)

SCHAEFER: The release of carbon from permafrost is irreversible. Just like fossil fuels. Fossil fuels - once you drill the carbon, drill the oil and burn it, there's no way to put that oil back into the ground. In permafrost, once you thaw out the organic matter and it decays, there's no way to put that organic matter back into the permafrost.
So what it means is that we have to reduce our emissions even more in order to hit a target atmosphere CO2 concentration. The primary results of our paper is that permafrost can release a huge amount of carbon, and that we really have to account for that carbon when developing our global strategies to reduce fossil fuel emissions.

The predictions are too optimistic because the models are incomplete... and we just don't know enough about systems such as permafrost to include them. I wish they'd say so when telling us that we'll be seeing ice free summers in the arctic by 2070... when in fact it may occur within the next 5 years.

Earth's permafrost likely to disappear by 2200 due to global warming: study

Earth's permafrost likely to disappear by 2200 due to global warming: study

Using Intergovernmental Panel on Climate Change scenarios and land-surface models for the study, the researchers ran multiple Arctic simulations assuming different rates of temperature increases to forecast how much carbon may be released globally from permafrost in the next two centuries.

After taking into account all of the permanently frozen ground at high latitudes around the globe, the researchers estimate a release of roughly 190 billion tons of carbon, most of it in the next 100 years
...
"The amount we expect to be released by permafrost is equivalent to half of the amount of carbon released since the dawn of the Industrial Age," said Schaefer.

Note: the IPCC was way too optimistic