Earth can be twice as hot as expected

The Earth could end up being twice as hot as projected by climate models, even if the world reaches the goal of limiting global warming to less than two degrees Celsius, according to a study. Nature Geoscience, has shown that sea levels can rise six meters or more even if the Paris climate goals are met.

The results are based on observations of three warm periods over the course of 3.5 million years. warmer than the pre-industrial temperatures of the 19th century.

Research also revealed how large areas of polar ice caps could collapse and significant changes to ecosystems could see the Sahara Desert become green and the edges of the rainforests turn into fire-dominated savannah.

"Observations from past warm-up periods suggest that a number of enhancer mechanisms, which are poorly represented in climate models, increase long-term warming beyond the climate project." This suggests that the Carbon budget to avoid 2 degrees Celsius of global warming can be much lower than expected, leaving a very small margin of error to achieve the Paris targets, "said Hubertus Fischer of the University of Bern In Switzerland, to get their results, the researchers examined three of the best documented warm periods, the Holocene thermal maximum (5,000 to 9,000 years ago), the last interglacial period (there are 129 000 to 116,000 warm period of the middle of the Pliocene (3,3-3 million years)

The warming of the first two periods was caused by predictable changes in the orb Earth's ite, while the mid-Pliocene was the result of atmospheric concentrations of carbon dioxide that were The combination of a wide range of measurements of ice cores, layers of sediments, fossils, dating to the 39, using atomic isotopes and a host of other established methods of paleoclimate, the researchers reconstructed the impact of

In combination, these periods clearly show how a more earthly warm weather would appear once the climate stabilized. By contrast, today, our planet is warming much faster than any of these times, as human-caused carbon dioxide emissions continue to grow.

Even if our emissions ceased today, it would take centuries or millennia to reach equilibrium. the changes in the Earth under these conditions were profound – there were substantial withdrawals of the Antarctic and Greenland icecaps and, as a result, the sea level rose by at least six meters; marine plankton ranges have been reorganized to reorganize entire marine ecosystems; the Sahara became greener and forest species moved 200 km to the poles, as did the tundra; High altitude species declined, temperate tropical forests were reduced and in Mediterranean areas fire-dominated vegetation dominated.

"Even with only 2 degrees Celsius of warming – and potentially only 1.5 degrees Celsius – the significant impacts on the Earth's system are profound." We can expect sea level rise become irrepressible for millennia, affecting much of the world's population, infrastructure and economic activity, "said Mr. Mix.