Unum
2018-07-06 05:59:51 UTC
https://phys.org/news/2018-07-global-climate.html
A new study based on evidence from past warm periods suggests global warming
may be double what is forecast.
Future global warming may eventually be twice as warm as projected by climate
models and sea levels may rise six metres or more even if the world meets the
2°C target, according to an international team of researchers from 17
countries.
The findings published last week in Nature Geoscience are based on
observational evidence from three warm periods over the past 3.5 million years
when the world was 0.5°C-2°C warmer than the pre-industrial temperatures of
the 19th Century.
The research also revealed how large areas of the polar ice caps could
collapse and significant changes to ecosystems could see the Sahara Desert
become green and the edges of tropical forests turn into fire dominated
savanna.
"Observations of past warming periods suggest that a number of amplifying
mechanisms, which are poorly represented in climate models, increase long-term
warming beyond climate model projections," said lead author, Prof Hubertus
Fischer of the University of Bern.
"This suggests the carbon budget to avoid 2°C of global warming may be far
smaller than estimated, leaving very little margin for error to meet the Paris
targets."
A new study based on evidence from past warm periods suggests global warming
may be double what is forecast.
Future global warming may eventually be twice as warm as projected by climate
models and sea levels may rise six metres or more even if the world meets the
2°C target, according to an international team of researchers from 17
countries.
The findings published last week in Nature Geoscience are based on
observational evidence from three warm periods over the past 3.5 million years
when the world was 0.5°C-2°C warmer than the pre-industrial temperatures of
the 19th Century.
The research also revealed how large areas of the polar ice caps could
collapse and significant changes to ecosystems could see the Sahara Desert
become green and the edges of tropical forests turn into fire dominated
savanna.
"Observations of past warming periods suggest that a number of amplifying
mechanisms, which are poorly represented in climate models, increase long-term
warming beyond climate model projections," said lead author, Prof Hubertus
Fischer of the University of Bern.
"This suggests the carbon budget to avoid 2°C of global warming may be far
smaller than estimated, leaving very little margin for error to meet the Paris
targets."