Extreme temperatures are setting heat records around the world almost every year. And it will become more and more common, scientists say.

study in Nature Climate Change yesterday finds that about 60% of the world will experience monthly temperature records every year by the end of the century if global greenhouse gas emissions don’t decline. That’s a milestone never before recorded by humans. Developing countries and small island nations are expected to be the hardest hit.

Also, the frequency of “smashed” records—records broken by at least 1 degree Celsius, or 1.8 degrees Fahrenheit—will also rise with the warming climate, the study suggests.

Conducted by Scott Power and François Delage of Australia’s Bureau of Meteorology, the research relied on simulations from 22 climate models. The scenarios tested included a business-as-usual approach, in which greenhouse gas emissions continue unmitigated into the future, as well as a scenario that assumes stringent climate action that would limit global warming to about 2 C.

In both scenarios, the frequency of record-breaking heat is higher than it would be in a world with no human-caused warming. But the risk is substantially higher in the business-as-usual scenario.

With no climate action, some nations close to the equator could experience as many as two dozen new heat records each decade—that’s an average of more than two every year—by the end of the century. But with strict climate action, in keeping with the goals of the Paris climate agreement, that number could drop to three or fewer per decade.

Altogether, the study finds that about 60% of the world will see a temperature record set in at least one month out of the year by the end of the century under a business-as-usual trajectory, and about 9% of the world will see those records smashed by a degree Celsius or more. Under the strict mitigation scenario, about 13% of the world will see a new monthly record each year, and just over 1% of the world will see those records smashed.

The study warns that even with strong climate action, unprecedented levels of heat will become more common throughout the rest of the century. Studies increasingly highlight the dangers of excessive heat and the rising number of additional deaths it’s expected to cause in the coming decades.

The paper underscores the idea that conditions will be far worse with no climate action.

“The benefits of reducing emissions, in terms of both reducing the pace at which high temperature records are set and restricting the magnitude by which records are broken, are very clear,” the authors state.

In the past few weeks, some parts of the Northern Hemisphere have already experienced a string of record-breaking heat events. Multiple cities in the western U.S. were forced to issue advisories for extreme heat earlier this month as temperatures soared over 100 F, breaking June temperature records in places like San Francisco.

Meanwhile, an intense and long-lasting heat wave in India has already killed dozens since it began last month. Temperatures in the capital of New Delhi reached a record-breaking 118 F on June 10, the hottest day ever recorded there in June. In other parts of the country, temperatures soared to a blistering 123 F.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news atwww.eenews.net.