18 Jan 2018

Scientists refine global warming predictions

10:39 am on 18 January 2018

Global warming is likely to be between 2.2 and 3.4 degrees, a new climate change study says, worse than some estimates but a relief to those fearing the worst.

A picture by NASA's Aqua satellite taken on September 3, 2010 shows the Arctic sea ice. The Arctic Ocean's dynamic layer of sea ice that grows each winter and shrinks each summer, reaching its yearly minimum size each fall. The ice cools the planet by reflecting sunlight back into space.

Photo: AFP

A University of Exeter study estimated temperature rises - caused by a doubling of the pre-industrial levels of CO2 in the atmosphere - could range between 2.2 and 3.4°C.

This narrows down previous, widely acknowledged estimates of between 1.5° and 4.5°C.

The Paris Agreement currently aims to hold the global average temperature increase to less than 2°C above pre-industrial levels.

New Zealand Climate Change Research Institute Director Professor David Frame said other recent studies indicated similar figures, further reinforcing predictions made by scientists.

He said although the International Panel on Climate Change have previously agreed to the 1.5°C and 4.5°C prediction, they may narrow this as a result of such studies.

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Photo: 123RF

He said while the study helps to more confidently rule out higher levels of warming, it also rules out low degrees of warming as well.

"It gives the people who think it's the end of the world and the people who think it's nothing to worry about a problem, because the evidence keeps stacking up, that climate change is a lot like we've long thought," he said.

In regards to the Paris Agreement, Professor Frame said these figures show nations perhaps need to do more.

"The world accumulative efforts under Paris don't get you to 2°C, so all the countries will have to keep working on that problem."

He said the world was already halfway towards being 2°C above pre-industrial levels.

"We're already seeing some really significant impacts of climate change, we're seeing a lot of heat waves and extreme weather events, climates are shifting, growing seasons are changing, so I think you'll see an increase on all those impacts."

He added it was an important paper for the climate modelling community, as this method is one of the main ways scientists compare models.

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