Impact of natural greenhouse emissions on Paris targets revealed

Impact of natural greenhouse emissions on Paris targets revealed

SOURCE: Centre of Ecology and Hydrology, National Environment Research Council DATE: July 9, 2018 SNIP: Global fossil fuel emissions would have to be reduced by as much as 20% more than previous estimates to achieve the Paris Agreement targets, because of natural greenhouse gas emissions from wetlands and permafrost, new research has found. The additional reductions are equivalent to 5-6 years of carbon emissions from human activities at current rates, according to a new paper led by the UK’s Centre for Ecology & Hydrology. Natural wetlands are very wet regions where the soils emit methane, which is also a greenhouse gas. The methane emissions are larger in warmer soils, so they will increase in a warmer climate. Permafrost regions are those which are permanently frozen. Under a warming climate permafrost regions begin to thaw and as a result the soils begin to emit carbon dioxide, and in some cases methane, into the atmosphere. The greenhouse gas emissions from natural wetland and permafrost increase with global temperature increases, this in turn adds further to global warming creating a “positive feedback”...
The Arctic’s carbon bomb might be even more potent than we thought

The Arctic’s carbon bomb might be even more potent than we thought

SOURCE: Washington Post DATE: March 19, 2018 SNIP: For some time, scientists fearing the mass release of greenhouse gases from the carbon-rich, frozen soils of the Arctic have had at least one morsel of good news in their forecasts: They predicted most of the gas released would be carbon dioxide, which, though a greenhouse gas, drives warming more slowly than some other gases. Scientists obviously weren’t excited about more carbon dioxide emissions, but it was better than the alternative: methane, a shorter-lived but far harder-hitting gas that could cause faster bursts of warming. Now even that silver lining is in doubt. Research released Monday suggests that methane releases could be considerably more prevalent as Arctic permafrost thaws. The research finds that in waterlogged wetland soils, where oxygen is not prevalent, tiny microorganisms will produce a considerable volume of methane, a gas that doesn’t last in the air much more than a decade but has a warming effect many times that of carbon dioxide over a period of 100 years. “What we can definitely say is that the importance of methane was underestimated until now in the carbon studies,” said Christian Knobloch, a researcher at Universität Hamburg in Germany and the lead author of the study, published in Nature Climate...
Scientists find massive reserves of mercury hidden in permafrost

Scientists find massive reserves of mercury hidden in permafrost

SOURCE: AGU DATE: February 5, 2018 SNIP: Researchers have discovered permafrost in the northern hemisphere stores massive amounts of natural mercury, a finding with significant implications for human health and ecosystems worldwide. In a new study, scientists measured mercury concentrations in permafrost cores from Alaska and estimated how much mercury has been trapped in permafrost north of the equator since the last Ice Age. The study reveals northern permafrost soils are the largest reservoir of mercury on the planet, storing nearly twice as much mercury as all other soils, the ocean and the atmosphere combined. Warmer air temperatures due to climate change could thaw much of the existing permafrost layer in the northern hemisphere. This thawing permafrost could release a large amount of mercury that could potentially affect ecosystems around the world. Mercury accumulates in aquatic and terrestrial food chains, and has harmful neurological and reproductive effects on animals. The study found approximately 793 gigagrams, or more than 15 million gallons, of mercury is frozen in northern permafrost soil. That is roughly 10 times the amount of all human-caused mercury emissions over the last 30 years, based on emissions estimates from...
The permafrost bomb is ticking

The permafrost bomb is ticking

SOURCE: Yale Climate Connections DATE: February 2, 2018 SNIP: About a fifth of the Northern Hemisphere landmass is permafrost, ground that has been mostly frozen for half a million years or more. Now there are signs of thaw appearing in many places across this vast landscape circling the Arctic, and at accelerated rates. It is only a matter of time until the incremental thawing of the permafrost reaches a tipping point of no return, a state of accelerated and irreversible change, the side effects of which might well push other parts of the Arctic beyond their own tipping points. The major side effect of a thawing permafrost is that it will further enhance global warming with the release of large quantities of methane, a potent greenhouse gas. During the last two million years, the climate has periodically shifted between cold (glacial) and warm (interglacial) states. We are currently in an interglacial that began about 11,000 years ago. Not coincidentally, the beginning of this warm stable period marked the dawn of agrarian societies and complex human civilizations. The last time there was a large-scale thaw of the permafrost was four interglacials ago. At the time of the thaw, about 450,000 years ago, the climate was about 1.5°C warmer than pre-industrial temperatures. Today, the temperature is nearly as warm – 1°C hotter than in pre-industrial times. Even more worrisome is the rate of the current warming, unprecedented in over 50 million years of geological history. Is it too late to prevent a regime shift in the Arctic? Possibly. That by no means implies that we might as well sit back and...
Changing landscape means some Arctic ponds may potentially be a significant source of carbon emissions

Changing landscape means some Arctic ponds may potentially be a significant source of carbon emissions

SOURCE: AAAS (EurekAlert) DATE: February 1, 2018 SNIP: A new Canadian study has found that carbon released by some ponds in the High Arctic could potentially be a hidden source of greenhouse gas emissions. The study looked at how dissolved organic carbon (DOC) stored in Arctic permafrost – which is thawing at an accelerated rate due to climate change – is being released into Arctic watersheds as a result of physical disturbances that relocate nutrients across the landscape. For the first-time researchers were able to determine that the chemical composition of carbon in these ponds is vastly different than in rivers in the High Arctic. “These ponds in the High Arctic seem to be hotspots for DOC degradation,” says Myrna Simpson, Professor of Environmental Science at U of T Scarborough and co-author of the research. “Very little consideration has been given to what’s happening with DOC in these ponds that are all over the Arctic, and it could potentially be a source of CO2 emissions released into the atmosphere with these...