Global temperatures will rise about 4 ° C by 2100 - Reuters

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MADRID, December 31 (EUROPA PRESS) –

Global average temperatures increase by at least 4 ° C by 2100 and potentially more than 8 ° C by 2200 if carbon dioxide emissions are not reduced, according to new research published in the journal ‘Nature’. The scientists found that global climate is more sensitive to carbon dioxide than noted in most previous estimates.

This new research also seems to solve one of the great unknowns of climate sensitivity issues, the role of cloud formation and whether this will have a positive or negative effect on global warming. The key to this estimation can be found in the observations in the real world around the role of water vapor in cloud formation.

“Previously, estimates of the sensitivity of global temperature to a doubling of carbon dioxide ranged between 1.5 ° C and 5 ° C. This new research talk that global average temperatures will rise by between 3 ° C 5 ° C, with a doubling of carbon dioxide, “said lead author Steven Sherwood, the Centre of Excellence for Climate at the University of New South Wales.

Observations show that when water vapor is absorbed by the atmosphere through evaporation, upwelling may rise 15 kilometers into clouds that produce heavy rains or rising a few miles before returning to the surface without forming rain clouds.

When updrafts rise a few miles total cloud cover is reduced as more steam pulling away from the higher regions of cloud formation. But water vapor is not far from the regions of cloud formation when there are only 15 kilometers deep in the updrafts.

The researchers found that climate models show low global temperature response to carbon dioxide in this process include insufficient water vapor lower level. Instead, almost all simulated updrafts at an elevation of 15 km and cloud formation.

When

are present deeper updrafts in climate models, more clouds are formed and there is an increased reflection of sunlight. Consequently, the global climate in these models becomes less sensitive in its response to atmospheric carbon dioxide. However, real-world observations show that this behavior is wrong.

When processes in climate models are corrected to match observations in the real world, models produce cycles with steam at a wider range of heights in the atmosphere, causing fewer clouds are formed under the weather warms. This increases the amount of sunlight and heat entering the atmosphere and as a result, increases the sensitivity of our climate to carbon dioxide or any other disturbance.

The result is that when the processes of water vapor are represented correctly, climate sensitivity to a doubling of carbon dioxide, which will occur in the next 50 years, means we can expect a temperature rise of at least 4 ° C by 2100.