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Global methane emissions have risen nearly 10% over the past 2 decades, resulting in record-high levels of the powerful greenhouse gas. Atmospheric concentrations of the gas — 1,875 parts per billion last year — are now more than 2.5 times above pre-industrial levels. Emissions have been mostly driven by agriculture and the natural-gas industry. Increasing red-meat consumption propelled a 12% increase in emissions from agriculture in 2017 alone. “People may joke, but cows and other ruminants burp as much methane as the oil and gas industry,” says Earth-systems researcher Robert Jackson.
The US government has backed off of a visa rule change that put international students at risk of deportation if all their classes were taught online. The government agreed to rescind the change after it was sued by Harvard and the Massachusetts Institute of Technology. The issue had thrown the futures of more than one million foreign students — presently facing visa delays and pandemic-related travel restrictions — into doubt. Some students had already been turned away at US airports because of the rule.
Features & opinion
The COVID-19 pandemic has forced us to rethink what constitutes necessary travel — which could be a very good thing, argue climate scientist Milan Klöwer and three colleagues. Their calculations show that biennials, regional hubs and virtual attendance could slash emissions from big meetings by up to 90%.
3 tonnes per scientist
The 28,000 delegates to the Fall Meeting of the American Geophysical Union travelled 285 million kilometres there and back — almost twice the distance between Earth and the Sun — emitting, on average, the same amount of CO2 as the city of Edinburgh does every week.
Logician Kurt Gödel’s incompleteness theorems crushed the dream of a consistent set of basic axioms on which the foundations of mathematics could be built, and ushered in a world of unanswerable questions. Science writer Natalie Wolchover explains how Gödel “pulled off arguably one of the most stunning intellectual achievements in history” — and how mathematicians continue to come to grips with the consequences.
Shall we take a spin on the Moon? Archival restorer Dutchsteammachine has upscaled the original 12-frame-per-second film taken by Apollo 16 astronauts driving the Lunar Roving Vehicle to modern frame rates and synced it with the original audio so it feels just like being there.
With contributions by David Cyranoski