A study published in the journal “Nature Communications” considers that the rain would take the snow in the Arctic regions “one or two decades earlier” than expected so far and that “the changes will be more important than estimated previously “.
Le Monde with AFP
This is now a known fact: the Arctic warms up much faster than the average of the planet, resulting in a decline in the pack ice and an increase in humidity in the air. As a result, scientists provide for a significant increase in rainfall in these areas by the end of the century. But what deadline, and in what form?
A study published in the Journal Nature Communications compared the forecasts of the latest generation of climate models to previous modeling. Depending on the results of scientists, the rain would take the snow in the Arctic regions “one or two decades earlier” than expected so far.
“The changes will be more important and much earlier than noted previously, which will have major impacts on life in the region,” explains the main label of the study, Michelle McCrystall, at the agency France-Presse (AFP).
“In autumn, for example, where the change is the most important, the central area of the Arctic could make the transition around 2070 according to the recent models”, according to the researcher of the University of Manitoba in Canada. The old models planned a transition around 2090.
Everything will depend, however, of the magnitude of the warming. At the current rate, the rain should become majority globally on the Arctic before the end of the century, but limit warming to + 1.5 ° C – the most ambitious objective of the Paris Agreement – could help preserve a dominated region by the snow, according to the study.
“The worst impacts can be avoided”
These results show that “the worst impacts can be avoided”, if greenhouse gas emissions are drastically reduced, commented on Gavin Schmidt, from the NASA Goddard Institute of Space Studies, contesting a Party. of the study. For this researcher who did not participate in the study, the results do not prove that the rain would arrive faster than expected.
In all cases, cascading effects of snow and rain failover are expected. For example, the multiplication of rain episodes falling on the snow may increase the mortality of reindeer and caribou on which local communities depend on: animals can no longer access their food under the impenetrable ice layer that forms then. The decrease in snow cover will also reduce the “albedo effect” (ability to reflect solar energy), thus exacerbating warming, notes the study.
Mid-August, rain had been observed for the first time at the top of the Greenland Glaciary Cap, more than 3,000 meters above sea level. A “disturbing” event in this area that should, however, remain dominated by the snow at the XXI eth century, estimates Michelle McCrystal. However, it is not possible, however, to say whether it is an isolated event or a sign that reality could be worse than the models.