Saturday, 28 November 2020

Global Warming

Greenhouse Rise

The U.N. weather agency says that while global carbon emissions fell by as much as 17% globally at times during the COVID pandemic, the levels of greenhouse gasses in the atmosphere have continued to rise to even higher records this year.

“The lockdown-related fall in emissions is just a tiny blip on the long-term graph,” said World Meteorological Organization chief Petteri Taalas. “We need a sustained flattening of the curve.”

He added in a statement that such a rise in carbon dioxide levels as observed over the past four years has never been seen before, either in direct measurements from the atmosphere or in ice-core samples that reveal CO2 concentrations from up to 800,000 years ago.

Trees Lose their Leaves Earlier Due To Global Warming

Trees will start to shed their leaves earlier as the planet warms, a new study has suggested, contradicting previous assumptions that warming temperatures are delaying the onset of fall.

Every year, in a process known as senescence, the leaves of deciduous trees turn yellow, orange and red as they suspend growth and extract nutrients from foliage, before falling from the tree ahead of winter. Leaf senescence also marks the end of the period during which plants absorb carbon dioxide through photosynthesis.

Global warming has resulted in longer growing seasons — spring leaves are emerging in European trees about two weeks earlier, compared with 100 years ago, researchers said.

Increases in spring and summer productivity that come as a result of elevated carbon dioxide, temperature and light levels then actually drive trees to lose their leaves earlier, the experts found. The experts now predict by the end of the century, leaves might even fall off three to six days earlier than at present.



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