Guest essay by Eric Worrall
As Russian Arctic towns struggle with an unexpected early hard freeze, and Northern Europe struggles with harsh temperatures, climate scientists have announced that rain will dominate Arctic snow events by 2060.
Rain to replace snow in the Arctic as climate heats, study finds
Climate models show switch will happen decades faster than previously thought, with ‘profound’ implications
Rain will replace snow as the Arctic’s most common precipitation as the climate crisis heats up the planet’s northern ice cap, according to research.
Today, more snow falls in the Arctic than rain. But this will reverse, the study suggests, with all the region’s land and almost all its seas receiving more rain than snow before the end of the century if the world warms by 3C. Pledges made by nations at the recent Cop26 summit could keep the temperature rise to a still disastrous 2.4C, but only if these promises are met.
Even if the global temperature rise is kept to 1.5C or 2C, the Greenland and Norwegian Sea areas will still become rain dominated. Scientists were shocked in August when rain fell on the summit of Greenland’s huge ice capfor the first time on record.
The research used the latest climate models, which showed the switch from snow to rain will happen decades faster than previously estimated, with autumn showing the most dramatic seasonal changes. For example, it found the central Arctic will become rain dominated in autumn by 2060 or 2070 if carbon emissions are not cut, instead of by 2090 as predicted by earlier models.
“What happens in the Arctic doesn’t stay there,” said Michelle McCrystall at the University of Manitoba in Canada, who led the new research. “You might think the Arctic is far removed from your day-to-day life, but in fact temperatures there have warmed up so much that [it] will have an impact further south.
“In the central Arctic, where you would imagine there should be snowfall in the whole of the autumn period, we’re actually seeing an earlier transition to rainfall. That will have huge implications. The Arctic having very strong snowfall is really important for everything in that region and also for the global climate, because it reflects a lot of sunlight.”
The abstract of the study;
New climate models reveal faster and larger increases in Arctic precipitation than previously projected
As the Arctic continues to warm faster than the rest of the planet, evidence mounts that the region is experiencing unprecedented environmental change. The hydrological cycle is projected to intensify throughout the twenty-first century, with increased evaporation from expanding open water areas and more precipitation. The latest projections from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) point to more rapid Arctic warming and sea-ice loss by the year 2100 than in previous projections, and consequently, larger and faster changes in the hydrological cycle. Arctic precipitation (rainfall) increases more rapidly in CMIP6 than in CMIP5 due to greater global warming and poleward moisture transport, greater Arctic amplification and sea-ice loss and increased sensitivity of precipitation to Arctic warming. The transition from a snow- to rain-dominated Arctic in the summer and autumn is projected to occur decades earlier and at a lower level of global warming, potentially under 1.5 °C, with profound climatic, ecosystem and socio-economic impacts.
You might think climate modellers are pretty courageous making such a radical prediction, given the long term decline in Holocene temperatures, the history of failed “end of snow” predictions, the long term and statistically significant drop in Antarctic temperatures, and some very snowy recent Northern winters, but there seems to be a prevalent view amongst climate modellers that models are more significant than data.
As John Mitchell, Chief Research Scientist British MET once explained, “People underestimate the power of models. Observational evidence is not very useful”.