The usual suspects (BBC, Science Focus, Phys.org, The Independent, Metro UK, etc.) are worried that green spaces are visible from space, and snow cover will continue to retreat, with bad consequences for the Alpine eco-system, unless we stop burning fossil fuels. This is triggered by a new paper by Sabine Rumpf et al. From white to green: Snow cover loss and increased vegetation productivity in the European Alps. Excerpts from Science Focus in italics with my bolds.
Snow in the European Alps is melting, and invasive plant species are outcompeting native Alpine plants, satellite imagery has shown. Both findings will reinforce climate change, say scientists.
The changes noticed in a new study, which uses satellite data from 1984 to 2021, show that as much as 77 per cent of the Alps has experienced greening, where areas with previously low vegetation have suddenly seen a boom in plant growth.
While the new plants do take a small amount of carbon out of the atmosphere by photosynthesis, scientists say the greening has a much bigger negative effect on climate change, as less of the Sun’s light will be reflected away from the Earth meaning the planet will get warmer.
The Alps are expected to see a reduction in snow mass of up to 25 per cent in the next 10-30 years, according to the Intergovernmental Panel on Climate Change’s 2019 report. As the snow melts, there will be more rock falls and landslides, which could have devastating consequences.
The new study shows that the Alps is experiencing snow cover recession that can already be seen from space, which the authors warn will only get worse as time goes on.
In the changing mountain environments, native Alpine plants have suffered while new species have thrived. This is because the plants specialised to higher elevations have had to focus on long-term living in the Alps, sacrificing the characteristics that could make them more competitive in the short term.
However, over time Alpine Temperatures and Snow are variable in quasi-cycles
For example, consider Change in temperature for the Greater Alpine Region, 1760–2007: Single years and 20-year smoothed mean series from the European Environment Agency (EEA)
Yes there are warming and cooling periods, and a rise recently. However, summer minus winter half-years have declined the last century. Calendar year averages peaked in 1994. So the certainty about present conditions „only getting worse“ is founded on faith rather than facts.
Then consider the record of snow cover over a longer period than the last thirty years. Rutgers Snow Lab provides this graph:
So, a lot of decadal variation is evident. While 2020-21 snow extent is down from a peak in 2016, it was lower in 2007, and very much lower in 1988-1990. True, the last 30 years had generally less snow than 30 years prior to 1990. But who is to say that the next 30 won’t see a return to earlier levels, still with large decadal fluxes.
And a longer-term view of Alpine glaciers, shows how much climate change has gone on without the benefit of CO2 from humans.
Summer Temperatures (May – September) A rise in temperature during a warming period will result in a glacier losing more surface area or completely vanishing. This can happen very rapidly in only a few years or over a longer period of time. If temperatures drop during a cooling period and summer temperatures are too low, glaciers will begin to grow and advance with each season. This can happen very rapidly or over a longer period in time. Special thanks to Prof. em. Christian Schlüchter / (Quartärgeologie, Umweltgeologie) Universität Bern Institut für Geologie His work is on the Western Alps and was so kind to help Raymond make this graphic as correct as possible.
The combination of mild warming and higher CO2 has greatly benefited the biosphere globally, resulting in setting crop yield records nearly every year. It should not be surprising that Europe’s Alps participated in this greening of the land. But I object to the notion that humans caused it or can stop it by reducing emissions. We do not control the climate or weather, and both warming and cooling periods will come and go as they always have.
via Science Matters
June 7, 2022