Drawing upon lake sediment data from samples taken in the Tibetan Plateau, scientists have demonstrated that permafrost at high elevations is more vulnerable than arctic permafrost under projected future climate conditions.
Such research is significant, given that the world’s current permafrost contains 1,500 trillion grams of carbon. The release of event small fractions of this carries significant consequences for climate change.
While a lot of interest has been directed towards Artic permafrost, there are other parts of the planet that also require urgent attention. What the new research from the University of Arizona does is to show how Alpine permafrost is predicted to melt at a faster rate than arctic permafrost under current global warming conditions.
To gather the data needed for predictive modelling, the researchers used carbonate (a family of minerals). These minerals formed in a Tibetan Plateau lake. The study of carbonate allowed the researchers to estimate temperatures during the Pliocene period (5.3 to 2.6 million years ago) and the Pleistocene period (between 2.6 million and 11,700 years ago). Because the atoms in carbonate reflect the temperature at which the carbonate formed, the mineral can be used like a time-traveling thermometer.
The data modelling suggests that under current levels of atmospheric carbon dioxide, 20 percent of Arctic permafrost land area and 60 percent of Alpine permafrost land area will be lost in the future. This finding will carry implications for policy makers when it comes to climate remediation activities.
This research appears in Nature Communications, titled “Alpine permafrost could account for a quarter of thawed carbon based on Plio-Pleistocene paleoclimate analogue.”
In related news and connected to global warming in the 21st century, the Greenland ice sheet appears to be contributing several meters to sea-level rise in the centuries to come. There is some hope in this assessment as the Hokkaido University researchers suggests that effective climate change mitigation measures will greatly reduce its decay.
In terms of the difference that could be made, by the year 3000, the unabated warming pathway will cause an ice loss of 0.71 to 3.54 meters sea-level equivalent (SLE). However, if global interventions occur then a reduced emissions pathway means that the loss is only 0.16 to 0.4 meters SLE.
The review appears in the Journal of Glaciology, titled “Mass loss of the Greenland ice sheet until the year 3000 under a sustained late-21st-century climate”.
