Climate scientists meeting in #Korea are being urged to avoid relying on untested technologies as a way of keeping global temperature rise under 1.5C.
The Intergovernmental Panel on Climate Change will shortly publish a report on how the world might stay below this limit.
Early drafts said it would require machines to suck carbon out of the air.
The IPCC special report, to be released on Monday, is expected to point towards the use of technology as a critical part of efforts to keep below the guardrail figure.
Earlier versions of the document stated that all the pathways to keeping below 1.5C required rapid reductions in global greenhouse gas emissions with net-zero reached by the middle of this century.
If emissions continue at the present rate, the world would “overshoot” 1.5C by 2040. If this happens, researchers believe that carbon dioxide removal technologies, in some form, would be needed to help bring the Earth’s temperature back down.
The IPCC report is expected to mention a number of approaches that range from planting more trees, to direct air capture of CO2, to bioenergy with carbon capture and storage (BECCS).
The latter involves growing large amounts of plants that capture CO2, and then burning them for energy while capturing and storing the gas that is emitted.
This has long been a controversial approach – requiring huge amounts of land to grow crops for burning. Previous research calculated an area twice the size of India would be needed to help the world stay under 2C of warming this century.
“It sounds crazy, and it is crazy,” said Dr Glen Peters, a climate researcher at the Centre for International Climate and Environmental Research in Oslo, Norway.
“But this may be the only way to keep temperatures well below 2C.
“I struggle to see how the world can remove billions of tonnes of carbon from the atmosphere for decades, but if we want 1.5C then we have to accept that this may be the only possible pathway.”
Read more at: https://www.bbc.com/news/science-environment-45742191