PARIS: Countries should not count the carbon dioxide naturally sucked up by Earth’s forests in their net-zero climate plans, scientists said on Monday, warning that “vague” rules could lead to the world warming more than expected.
The scientists, who developed the original science behind net zero, issued their warning in a new study as countries gathered in Azerbaijan for the latest round of UN climate talks.
The world’s oceans, forests and soils absorb planet-warming carbon dioxide from the atmosphere, meaning they play a crucial role in efforts to prevent temperatures from rising further. These ‘natural carbon sinks’ currently suck up about half of all the carbon dioxide emitted by humanity.
Under the Paris Climate Agreement, countries have committed to limiting global warming to 1.5 degrees Celsius above pre-industrial times.
Although they didn’t specify how they would achieve that goal, scientists say the world needs to cut emissions by nearly half this decade and reach net zero by 2050 — when humanity will no longer emit more greenhouse gases than it captures.
Once emissions are close to zero, forests and oceans should be able to absorb some of the extra carbon dioxide that has built up in the atmosphere, allowing global temperatures to ‘stabilize’, says Myles Allen, a scientist at the University of Oxford and lead author of the study in the journal Nature. Allen helped develop the science behind Net Zero in the 2000s.
But a problem has arisen since that “didn’t occur to me at the time,” he told a news conference.
As countries have announced their climate plans, some have argued that the amount of carbon naturally removed by their forests and land would offset some of the emissions from their people and industries. But you can’t count on natural carbon sinks to “do two jobs at the same time,” Allen pointed out.
“If we want to count on them to reduce our historical emissions… we can’t use them at the same time to offset future fossil fuel emissions.”
Global warming risk
This may seem like a small adjustment in greenhouse gas accounting, but it could mean that the world thinks it is on track to limit warming to 1.5 degrees Celsius, when in fact it could shoot past 2 degrees Celsius’ and that warming will continue in the future’. he said.
Russia, for example, “apparently recently pointed out that they might be able to get to net zero while increasing their use of fossil fuels because they have such large forests,” Allen said.
The European Union recently began partially claiming the work of its forests as compensation for emissions, says Glen Peters, research director at the Center for International Climate Research in Oslo.
It’s not that countries are breaking the rules, Allen said: “It’s just the rules are a little vague.” Most countries and many major companies have announced some sort of net-zero plan, but the details of exactly how and when this will be implemented vary widely, threatening their integrity, experts warn.
‘Geological net zero’
The researchers called on the world to set its sights on ‘geological net zero’, which would mean that for every tonne of carbon dioxide emitted by a fossil fuel – the main source of emissions – a tonne would have to be sucked from the atmosphere. and permanently put back into the ground.
While there is hope for a boom in technologies that capture CO2 from the air, only 0.1 percent of CO2 emissions are currently captured and trapped — that should increase to 100 percent by mid-century, Allen said. Peters added: “If you don’t get the fossil fuels out of the ground in the first place, you’re well on your way to solving the problem.” Last week it was predicted that humanity would break another record for carbon dioxide emissions in 2024 – which is expected to be the hottest year on record.
Published in Dawn, November 19, 2024