The global economy will be 2% bigger by the end of the century if the world can hold global warming below 1.5 degrees Celsius, according to a new study.
Most models predict a period in which the world surpasses that mark for several years or decades, before cooling back down to the 1.5 degree mark (2.7 Fahrenheit) by 2100. This would require removing existing carbon from the atmosphere on an impractically large scale, according to research published in the journal Nature Climate Change.
Drawing on modeling from nine teams, lead researcher Keywan Riahi, director of the energy program at Austrian research institute IIASA, found that may be impossible, and a temporary overshoot would likely increase extreme weather such as flooding and wildfires. To avoid permanent damage to ecosystems, the world must avoid surpassing the mark altogether, the report warned. In doing so, there will be less need to remove carbon dioxide from the atmosphere — a process known as net-negative emissions.
“Rapid emissions cuts in the next few decades would mean there is no need to go net negative,” said co-author Christoph Bertram, a climate impact researcher at the Potsdam Institute in Germany. “Instead, global temperatures would plateau at a given level around the time we reach net-zero emissions.”
As well as protecting the planet, achieving net zero — a target of completely nullifying the amount of greenhouse gases produced by human activity — would have long-term economic benefits. “Upfront investment to achieve rapid transformations toward a global net-zero system will pay off in the long term,” Riahi said.
In fact, global GDP could grow even more than than 2%, according to another co-author, Laurent Drouet, a senior scientist at climate research group CMCC in Italy. Drouet said the calculation used in the study doesn’t include the economic damage of climate change, which would be more severe above 1.5 degrees.
The study warned that to remain beneath that threshold, countries must improve their emissions goals under the Paris Agreement framework. The current pledges imply a slow start to mitigation and need to be ramped up dramatically, the report said.
The transport sector is key to success, according to the study. A recent report by global climate leadership group C40 Cities says global public transit use must double by 2030 to meet the targets.
Daniel Huppmann, co-author and a researcher at the IIASA, called for radical change in transport to support decarbonisation. “A mobility revolution will be crucial to reducing dependence on net-negative emissions technologies and to mitigate their risks and negative societal impact,” he said.