Scientists have warned that the 1.5°C global warming limit negotiated in the Paris climate agreement could be broken as soon as 2026.
New research suggests that a natural fluctuation in the Pacific ocean may accelerate warming even faster than climatologists had predicted.
When the Interdecadal Pacific Oscillation is in its negative phase, it traps hot water in the deeper layers of the ocean, slowing global warming.
But when it shifts to its positive phase, as scientists suspect it is has, the process reverses, causing temperatures to rise at a faster rate.
In light of the findings, the researchers are now calling on politicians to commit to further measures to limit global warming.
Ben Henley, lead author, said in a statement: “If the world is to have any hope of meeting the Paris target, governments will need to pursue policies that not only reduce emissions but remove carbon from the atmosphere.”
“Should we overshoot the 1.5°C limit, we must still aim to bring global temperatures back down and stabilise them at that level or lower.”
Henley added that even if the IPO remains in a negative phase, temperatures are still likely to surpass the 1.5°C mark by 2031.
But Bill Hare, an Australian climate scientist, shared some reservations about the study in an interview with the Guardian.
He said the UN’s interpretation of when the 1.5°C limit could be said to have been breached was based on longer time periods than the study.
Hare also told the Guardian that the paper did not take into account countries’ attempts to limit greenhouse gas emissions under the Paris agreement.
But he added that the paper showed that “very ambitious near-term mitigation is required to limit warming to 1.5°C”.
Under the Paris agreement, global leaders pledged to keep warming “well below” 2°C above pre-industrial levels and limit the increase to 1.5°C.
US president Donald Trump is expected to make a decision about whether to withdraw the US from the Paris agreement in the next few days.