Flights aren’t down as much as you may think
Flight tracking website Flightradar24 says that in the last two weeks of March, commercial air traffic was only 41 percent below 2019 levels, to 36,491 flights. The site also says that last year it tracked almost 69 million flights (specifically: 68,948,849), a new record and an increase of 10 percent over 2018. Much of that wasn’t passenger traffic but cargo. But much was passenger traffic.
Arctic sea is ‘Atlantifying’ faster and algae are on the move
The Arctic Ocean increasingly resembles the Atlantic, becoming saltier, warmer, and in terms of the species of life living there. We knew that the average air temperature in the Arctic has risen twice as fast as much as the global average. Now scientists from the CNRS and Laval University, Quebec, report in Nature Communications that in the Barents Sea between Russia and Norway, where the Atlantic and Arctic oceans “meet”, hot spots have developed that more resemble the Atlantic than the Arctic, resulting among other things in accelerated ice melt. The Atlantic currents are demonstrating an unprecedented strengthening, accelerating Atlantification, and a marine algae called Emiliania, which usually dwells in temperate waters at lower altitudes, is increasingly to be found in the Arctic Ocean.
Arctic changes may lead to extreme weather in Eurasia within weeks
Think the Arctic is far, far away? Scientists have been studying in general how the accelerated heating of the Arctic may affect climate everywhere else, over seasons to decades. Now researchers from Fudan University in Shanghai suggest in Advances in Atmospheric Sciences that the effects of Arctic events may actually lead to extreme weather events in Eurasia within weeks.
Co-author Guokun Dai qualifies that it’s hard to nail down the cause and effect behind extreme weather (such as record-breaking temperatures, massive snowfalls) and also, observational data on Arctic weather is sorely lacking. But this could be key to improving forecasting, which has become ever less reliable as climate change advances.
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Extreme rain days rose fourfold in São Paulo over 70 years
Apropos extreme weather: Extreme rainfall days over São Paulo in Brazil increased fourfold over the last seven decades, researchers at the Natural Disaster Surveillance and Early Warning Center report in the Annals of the New York Academy of Sciences. But at the same time, these sheets of water falling are interspersed by longer dry spells. There were practically no days with heavy rain (more than 50 millimeters) in the 1950s, but for a decade now now they're happening two to five times a year, they write. But the number of consecutive days without any rain at all, and relatively hot to boot, has also gradually increased, the scientists report.
Carbon trapping by peatland projected to decline
Back in the upper northern hemisphere, the boggy peatlands that developed over the last 12,000 years as the glaciers retreated now cover about 3 percent of the Earth’s surface. Peatlands can beautifully preserve archaeological remains for the same reason they retain carbon: the climatic conditions hamper decay. Peatlands are estimated to contain about 20 percent of the carbon in the planet’s soil. But if the planet follows the trajectory of intense heating – and so far it is – by 2100 as the peatlands dry out, their carbon trapping capacity will be hugely reduced, a Nordic team warns in the journal of Global Change Biology. Similarly to thawing permafrost releasing not only ancient diseases, its melt releases methane as well. And the more methane gets released, the more global warming will accelerate.
Why one shouldn’t drain the melting peatland
When peatland dries out, it releases trapped carbon dioxide too. This isn’t a marginal issue: peatland drainage causes 5 percent of all anthropogenic greenhouse gas emissions on only 0.3 percent of the global land surface, a paper published in Nature Communications explains. (Jet plane traffic was responsible for about 2.4 percent of CO2 emissions in 2018. The oil and gas industry is estimated to be responsible for over 35 percent.) If you wet your desiccating peatland in order to stop the CO2 emissions, you wind up with methane emissions. So the choice of monkeying with peatland boils down to CO2 emissions from drained peat or methane emissions from rewetted peat. CO2 is a “weak but persistent” greenhouse gas. Methane is a potent but short-lived greenhouse gas. The team did the math and concluded: Better to promptly rewet drained peatland and suffer the methane burst than to let it dry out and let all that carbon escape.
The good news: Lab-grown meat advances
Estimating the amount cows contribute to climate change involves a vast number of parameters and unknowns, like all things biological and environmental. Their greenhouse gas emissions aren’t confined to cow farts: How much do emissions from their manure contribute? How about emissions from draught bovine used in the Third World? And then there are all the other animals we eat. In August 2019, the United Nations called on people to eat less meat for the sake of both the planet and their arteries. Now Shulamit Levenberg of the Technion – Israel Institute of Technology, Haifa, and colleagues report in Nature Food about a new cost-effective method to produce an edible scaffold for growing cultured meat made from soy protein and bovine cells. This could solve a key problem with the cultured meat industry: scaling it up to industrial levels.