LOS ANGELES (AP) — Southern California could see a record number of scorching days by mid-century as climate change heats up its cities, deserts and coastline, according to a study released Thursday.

Southern California probably will be warmer by about 3 to 5 degrees in the years 2041 to 2060, although the huge differences between inland and coastal areas, mountains and deserts mean that different areas will have different impacts, according to the UCLA study.

The study was commissioned by the city and conducted by UCLA's Department of Atmospheric and Oceanic Sciences. It downscaled global climate change computer models to the local region, breaking down predictions to 1.2-mile segments, and is 2,500 times more precise than previous climate models for the region, researchers said.

They said dense urban areas such as downtown Los Angeles probably will warm an average of 4 degrees, with a warming range of up to 6 degrees in the Mojave Desert.

The number of days where the temperature tops 95 degrees could triple in downtown Los Angeles and jump five-fold in the deserts, according to the study, while the hottest days could be record-breakers.

Such studies may play an important role in how local governments deal with the fallout of climate change. More hot days could affect power use as people turn on air conditioners, water use for lawns and traffic as people head to beaches to beat the heat.

"Longer, harsher heat waves will cause more cases of heat stroke and heat exhaustion - even among otherwise healthy people who believe they're immune - and higher temperatures mean more smog, with consequences for respiratory health as well," Dr. Richard Jackson, of UCLA's Fielding School of Public Health, said in a statement.

"UCLA's model projects climate changes down to the neighborhood level, allowing us to apply the rigor of science to long-term planning for our city and our region," Los Angeles Mayor Villaraigosa said at a news conference. "With good data driving good policies, we can craft innovative solutions that will preserve our environment and quality of life for the next generation of Angelenos."

Researchers, however, acknowledged that uncertainty remains and the temperature rise in Southern California could be far less or greater.

The exact rise in temperature depends, among other things, on whether governments make global efforts to control greenhouse gas emissions blamed for heating up the earth or continue a "business-as-usual" scenario, the study said.

"Because it is very unlikely that humans will emit less greenhouse gases than in the mitigation scenario, adaptation to a changing climate over the next few decades is probably inevitable in the Los Angeles region," the study said.

Either way, forecasters said climate change will seriously affect Southern California and governments must begin thinking about that challenge.

"The changes our region will face are significant, and we will have to adapt," said UCLA professor Alex Hall, the lead author of the study. "Every season of the year in every part of the county will be warmer. This study lays a foundation for the region to confront climate change. Now that we have real numbers, we can talk about adaptation."