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2 deg C 'not enough' as global warming red-line


LIMITING global warming to 2 deg C will not prevent destructive and deadly climate impacts, as once hoped, dozens of experts concluded in a score of scientific studies released on Monday.

A world that heats up by "2C" - long regarded as the temperature ceiling for a climate-safe planet - could see mass displacement due to rising seas, a drop in per capita income, regional shortages of food and fresh water, and the loss of animal and plant species at an accelerated speed.

Poor and emerging countries of Asia, Africa and Latin America will get hit hardest, according to the studies in the British Royal Society's Philosophical Transactions A.

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The 197-nation Paris climate treaty, inked in 2015, vows to halt warming at "well under" 2C compared to mid-19th century levels, and "pursue efforts" to cap the rise at 1.5C.

With just one degree of warming so far, Earth has seen a crescendo of droughts, heatwaves and storms ramped up by rising seas.

Voluntary national pledges made under the Paris pact to cut CO2 emissions, if fulfilled, would yield a 3C world at best.

Researchers led by Felix Pretis, an economist at the University of Oxford, predict that two degrees of global warming will see GDP per person drop, on average, 13 per cent by 2100, once costly climate change impacts are factored in.

Under a 2C scenario, oceans rise about half a metre over the course of the 21st century, but well over a metre by 2300, another study found.

"When the planet warms, it takes the ocean hundreds, if not thousands, of years to fully respond," said lead author Robert Nicholls, a professor of coastal engineering at the University of Southampton.

That's bad news for 500 million people living in "highly vulnerable" low-lying deltas, mainly in Asia, along with some 400 million people in coastal cities, many of which are already sinking due to over-construction or collapsing water tables. AFP