Long-term forecast is for more very hot days in L.A.

That’s the upshot of a new report from climate experts at the UCLA Department of Atmospheric and Oceanic Sciences.

The report, published in the Journal of Climate, says that if nothing is done to control greenhouse gas emissions, the number of extreme heat days – over 95 degrees – could triple or even quadruple by 2050.

That would mean as many as 22 days of extreme heat in downtown L.A. each year – and as many as 74 in the San Gabriel Valley. Even Long Beach could see more than two weeks of very hot weather each year.

Inland areas would be hit hardest. Palm Springs could roast under 95-degree-plus temperatures for nearly six months a year if the researchers are on target.

The new study builds on earlier research from the Scripps Institution of Oceanography and others showing that Southern California is likelier to get warmer because of climate change.

Meanwhile, a companion report published by scientists at UCLA’s Luskin Center for Innovation, cautions that the region’s water supplies and electrical capacity will be heavily strained by an increase in the number of very hot days. Those researchers see a dangerous cycle, in which more hot days increase demand for air conditioning and power, which will release more carbon dioxide emissions into the atmosphere.