When birds of a feather don’t migrate together
Israel is on the route for birds migrating between Europe and Africa. That explains why the Holy Land attracts not only pilgrims but birdwatchers. But, to generalize, the rapid pace of global warming is confusing the birds, Israeli scientists warn in Science Advances.
The redstart, for instance, lives in Africa and Arabia but breeds in Europe. The males are flying out earlier but the female isn’t, based on data collated in Israel; other studies haven’t found that correlation and suggest the ladies are adjusting migration speed en route. But sexual differences in changes to migration timing have also been shown in the willow warbler in Sweden.
Or take the blackcap, whose trigger for migration involves vegetation, which is being affected by climate change. Point being, as climate change advances, some, or many, birds may not be able to adjust their migration timing appropriately, which endangers their survival, irrespective of other warming-related problems like extreme weather.
Deadly toxin from pond scum detected in air
We knew that pond scum, aka algal blooms, aka cyanobacteria colonies in fresh or seawater, is “bad.” These creatures may descend from the earliest life on earth, but frankly they stink and suffocate other water life when they procreate out of control.
Now researchers reporting in Lake and Reservoir Management have shown that toxin emitted into the water by pond scum in Capaum Pond on Nantucket Island, Massachusetts was detectable in the air. Not just any toxin: The scum was emitting anatoxin-a, which has a cute nickname: Very Fast Death Factor.
Drinking water with VFDF can be fatal. How did it reach the air? Not clear; maybe the molecule itself or individual cyanobacteria were blown by the wind. This does not augur well, however. Climate change is driving the rampant development of algal blooms, which are extraordinarily hard to “treat”; the Israeli company BlueGreen Water Technologies has reported success with its innovative solution.
Scientists calculate Antarctic glacier’s tipping point
The chief contributors to rising sea levels are Greenland and Antarctica, and clearly Antarctica’s speediest glacier, Pine Island, is losing ice into the sea fast. Now researchers from Northumbria University in England have not only confirmed that tipping points could be crossed, leading to irreversible retreat and rising sea levels, they’ve calculated what these tipping points are.
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Reporting in The Cryosphere, they show that the glacier has at least three tipping points, and the third and final one, triggered by average ocean temperatures increasing by 1.2 degrees Celsius, leads to irreversible retreat of the entire glacier, which could raise sea levels by meters. When? We don’t know. But prehistory provides a stark warning:
Melting ice sheets boosted sea levels 3.6 meters per century
Climate change has led Earth into uncharted territory, rendering accurate forecasting impossible. But indicators from the past can be helpful. The massive melting of ice sheets in the past boosted sea levels at around 3.6 meters per century, offering vital clues on what lies ahead if climate change continues unabated, researchers write in Nature Communications.
When was this? Very recently in fact – at the end of the last ice age, around 14,600 years ago. In the space of about 500 years, sea levels rose 500 meters. Apparently the main source of melt was the Northern Hemisphere, less so the Antarctic ice sheet – and note that the far-Northern Hemisphere has been heating up faster than anywhere else. Low-lying land massively flooded, as will happen to us, experts warn.
In his book “Moving to Higher Ground” published Tuesday, oceanographer John Englander spells out what is known, what awaits us and what can be done.
‘To intervene or not to intervene’
Nine of the hottest years in recorded human history have occurred in the past decade, Michigan State University points out. Life as we know it?
Never mind that, the future of life is at stake. Climate-changing emissions haven’t stopped – the coronavirus lockdowns brought no relief; we’re still on trajectory for the worst-case scenarios, which has brought entirely theoretical geoengineering proposals to the fore.
So far, technologies such as massive mirrors that reflect sunlight back into space have been considered too risky because we have no clue how they would affect the planet. But some experts are starting to suggest there’s no choice. (These technologies don’t exist yet, by the way.)
As one professor, Phoebe Zarnetske, puts it: Sunlight deflection may cool Earth’s surface to a certain global temperature target, but the cooling may be unevenly distributed, affecting ecosystems and biodiversity. Rainfall and surface ultraviolet radiation would change, acid rain would increase, and therefore so would ocean acidification. A magic bullet this is not.