The pace of global warming is likely to quicken in coming years as natural processes in the Pacific switch from serving as a brake to an accelerator, placing the planet on course to exceed a landmark level within a decade, according to a new paper.

The Interdecadal Pacific Oscillation (IPO), a cycle that lasts 10-30 years and affects how much heat is absorbed in the Pacific, started to switch to its positive or "warm" phase since 2014. During positive periods, the central ocean is relatively warm compared with surface waters at higher latitudes.

The paper by Melbourne University researchers, published this week in Geophysical Research Letters, argues the preceding negative phase - lasting from 2000-2014 - may have provided a "temporary buffer" for surface temperature increases and "cushioned the impacts of global warming on extreme events, such as heatwaves".

"A turnaround of the IPO to its positive phase could initiate a period of accelerated warming over the next one or two decades," Ben Henley and Andrew King state. "This would likely lead to the Paris target of 1.5 degrees (warming since pre-industrial times) being surpassed within the next decade."