August 11, 2022

expert reaction to study looking at rate of Arctic warming

A study, published in Communications Earth & Environment, suggests that the Arctic is warming at a faster rate than the rest of the globe.

Dr Ella Gilbert, Regional Climate Modeller, Atmosphere, Ice and Climate team, British Antarctic Survey, said:

“It’s clear that Arctic warming has been gathering pace in recent decades, so it doesn’t seem far-fetched that the rate of change is four times the global average. As the authors note however, the amount of polar amplification depends on the area and time period that is considered, ranging from 3 to 4 times for smaller and larger definitions of the ‘Arctic’. The difficulty of measuring and modelling our complex polar regions also makes it hard to nail down an exact number. However, regardless of the precise value of polar amplification, this study supports plenty of others that show the Arctic continues to warm, with consequences for all of us.”

Prof Jonathan Bamber, Director of the Bristol Glaciology Centre, University of Bristol, said:

“This is an important and robust study of decadal temperature trends in the Arctic. The conclusions drawn, at least over the last four decades, are reasonable but it is important to note that the focus of this study – Arctic Amplification (AA) – is not constant over time. Over longer timescales AA will decrease and lie closer to the modelled estimates that the authors compare the observations with.

“The conclusions are important because the Arctic contains several delicately balanced components of the climate system which have the potential to respond to Arctic warming with globally damaging consequences. Two of these systems are permafrost and the Greenland Ice Sheet. The former contains enough carbon locked in its frozen soil to raise global temperatures by about 3 degrees if released to the atmosphere and the latter contains enough ice to raise global sea levels by 7.4 m if it all melted. Both are very sensitive to regional warming and both could pass an irreversible threshold if Arctic Amplification continues at the rate presented in this study.”

Dr Helene Hewitt OBE, Met Office science fellow and IPCC author on Ocean, Cryosphere and sea level, said:

“The Arctic is undergoing a faster rate of warming than anywhere else on earth, bringing rapid rates of climate change to the region. As Arctic temperatures increase, we will see further loss of seasonal snow cover, land ice and sea ice in the region and permafrost thawing will be amplified. What happens in the Arctic matters particularly to the UK because it influences our weather patterns.”

Prof Julienne Stroeve, Professor of Polar Observation & Modelling, UCL, said:

“One of the reasons why this study shows a larger warming rate than previously reported is (1) they go through 2021, and (2) they use a different southern boundary that removes more of the land areas. If they use the same 60N southern boundary then they get an estimate similar to the recent AMAP report.

“The key results from the paper are then that most climate model simulations fail to capture the rate of Arctic Amplification, which suggests internal variability is a strong player in the current large Arctic Amplification.

“However, we already know that the models are conservative in regards to their sea ice loss, and thus it’s not surprising that the models underestimate the rate of Arctic Amplification since sea ice loss explains quite a bit of this warming in autumn/winter. The outsized warming in April is likely linked to similar deficiencies in modelling the snow depth.

“I think the paper falls short in actually evaluating the drivers of the Arctic Amplification underestimation in the climate models. This is something they should have looked at and could have without too much difficulty. They mention in the introduction the factors that contribute to Arctic Amplification, and they could have provided values for these metrics.”

* ‘The Arctic has warmed nearly four times faster than the globe since 1979’ by Mika Rantanen et al. was published in Communications Earth & Environment at 16:00 UK time on Thursday 11 August 2022.

DOI: 10.1038/s43247-022-00498-3

Declared interests

Prof Jonathan Bamber: “None but I have written a piece for The Conversation on this paper that will be released tomorrow.”

Prof Julienne Stroeve: “None that I can think of.”

For all other experts, no reply to our request for DOIs was received.