Half-degree less warming can avoid precipitation extremes: Study

Just a half-degree Celsius less warming could prevent extreme precipitation events, and make a major difference when it comes to climate change, according to a study.

Published in the journal Nature Communications, the study confirms the significance of the incremental global warming limits articulated by the Paris Agreement.

A total of 175 parties (174 countries and the European Union) agreed to work to stop global warming from increasing more than two degrees Celsius, and every effort is to be made to limit the increase to 1.5 degrees Celsius and prevent the last half of a degree of warming.

The half-degree Celsius is so significant that it could be the barrier preventing extreme precipitation events, according to Tianjun Zhou, a professor at the University of Chinese Academy of Sciences.

"As the climate warms, both the mean state and the variability of extreme precipitation are projected to increase, inducing more intense and dangerous extreme events," Zhou said.

"Limiting global warming to 1.5 degrees Celsius, compared to two degrees Celsius, would reduce areal and population exposures to once-in-10-year or once-in-20-year extreme precipitation events by approximately 20 to 40 per cent," Zhou said.

Researchers combined CMIP5, an archive of comprehensive climate models, with socio-economic projections to investigate future climate changes and the accompanying impacts.

They specifically examined extreme precipitation events in the global monsoon region, which sprawls north and south from the Earth's equator and includes nearly two-thirds of the world population.

This region is more impacted by extreme precipitation than any other land mass on Earth.

The scientists found that by reducing the global warming limit by 0.5 degrees Celsius, a significant number of extreme precipitation events and their impacts could be avoided.

"Realising the 1.5 degrees Celsius low warming target proposed by the Paris Agreement could robustly benefit the populous global monsoon region, in terms of lower exposure to precipitation extremes," Zhou said.

"(Our results) are robust across climate models, different definitions of dangerous events, future greenhouse gas emissions scenarios, and population scenarios," said Zhou.

The researchers will continue to study the physical processes of how 0.5 degrees Celsius less warming affects dangerous precipitation extremes.

They are also calling others to attention and action in regions that are the most sensitive to the 0.5 degrees Celsius additional warming.