Global Warming Might Hit Threshold by 2026

Global temperatures could rise by more than 1.5 degrees Celsius by 2026 if the Interdecadal Pacific Oscillation shifts into a positive phase.

The Interdecadal Pacific Oscillation, or IPO, is an ocean-atmosphere climate phenomenon that drives weather patterns and global temperatures. It's similar to the Pacific Decadal Oscillation, but covers a large portion of the Pacific, UPI reported.

According to a new study by climate scientists at the University of Melbourne, a positive phase IPO would dramatically accelerate global warming.

IPO has remained in a negative phase since 1999, but significant oceanic and atmospheric warming over the last three years suggests the phenomenon could be on the verge of a shift.

"Even if the IPO remains in a negative phase, our research shows we will still likely see global temperatures break through the 1.5 degrees Celsius guardrail by 2031," researcher Ben Henley said in a news release. Global temperatures have risen rapidly during previous positive phases, between 1925 and 1946 and again from 1977 to 1998. Another positive phase could once again spur rising temperatures.

"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 as well," Henley said.

"Should we overshoot the 1.5 degrees Celsius limit, we must still aim to bring global temperatures back down and stabilize them at that level or lower."

The results of the new study, published in the journal Geophysical Research Letters, suggests a slowdown in global warming over the last two decades could be explained by IPO's current negative phase.

"Although the Earth has continued to warm during the temporary slowdown since around 2000, the reduced rate of warming in that period may have lulled us into a false sense of security," Henley said.

"The positive phase of IPO will likely correct this slowdown. If so, we can expect an acceleration in global warming in the coming decades."