Impacts of climate change occur at lower temperatures than previously thought, new review finds

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"Southern Africa drought - Mozambique" by International Federation of Red Cross and Red Crescent via Flickr is licensed under CC BY 2.0
September 23, 2020

 

A new review of climate research has found that risks from climate related impacts, such as droughts, heatwaves and coral bleaching events occur at lower temperature increases than previously thought.

The review, published in Nature Reviews: Earth and Environment, examined the past nineteen years of reports from the Intergovernmental Panel on Climate Change (IPCC). These reports assessed and communicated risks from increasing average global temperature on human and natural systems.

However, the risk levels at given temperatures have not previously been compared across reports in a standardized way.  For the first time, this paper shows that at a given temperature, risks have generally increased with each assessment based on new, more comprehensive science.

"The risk of extreme events occurring at given temperatures is higher than we previously thought," says lead author Zinta Zommers, from the United Nations Office for Disaster Risk Reduction.

“In other words, twenty years ago high risks such as collapse of West Antarctic Ice Sheet or loss of tropical coral reefs were assumed to occur at much higher temperature increases and therefore much later in time. But now, the science indicates both the temperatures and time left has decreased.”

These findings are the result of accumulating scientific evidence on how temperature increases will affect the climate.

“Each successive IPCC assessment shows higher adverse impacts and risks for a given level of global warming than the previous one, because there has been progress in scientific understanding and increased information has been gathered,” commented Professor Rachel Warren, from the School of Environmental Science at the University of East Anglia.

“The need to act on climate change is now more pressing than ever if we are to limit these impacts”, says Professor Mark Howden, Director of the Climate Change Institute at The Australian National University.

“These findings also show that we cannot take for granted the period of time that we have left to act on climate change before extreme impacts are felt”.


Read the full journal article here.