GLOBAL WARMING IS REAL AND THE CLIMATE IS CHANGING FOR THE WORSE CAN WE FIX THE PLANET?

Byline: SUSAN ABRAM and DANA BARTHOLOMEW Staff Writers

The seas are rising, swallowing the Malibu shoreline. Snow falls on Mammoth Mountain later each year, leaving skiers in the lurch.

In the Angeles National Forest, trees grow more vulnerable to wildfires as bark beetles that thrive in hot weather proliferate, while water supplies remain fragile.

Hotter weather, increased fire danger, severe rainstorms and rising sea levels -- among the consequences of global warming -- are already creating a multitude of problems for Southern California, scientists said Friday.

``California is heading into unknown, dangerous territory if we don't take some action,'' said Bill Patzert, climatologist at the Jet Propulsion Laboratory in La Canada Flintridge. ``As sea levels rise, there will be more beach erosion.

``Instead of Malibu Beach, it'll be Malibu Cliffs and (David) Geffen's home'll be bouncing in the surf zone.''

In a report released Friday, a panel of international scientists said global warming is expected to continue for centuries. And mankind and our dependence on fossil fuels are ``very likely'' to blame for the phenomenon.

While the study does not list specific evidence for Southern California, local experts say clues abound in the present that offer a glimpse into the future.

``Over the short-medium term, the impacts of global warming will be felt in extreme events -- heat waves, wildfires, flooding, mudslides,'' said Amy Luers, a climate scientist with the Union of Concerned Scientists, based in Berkeley.

Luers was one of the many authors of a collaborative public-private study published last summer that assesses the risks posed by climate change on California.

In the past century, sea levels in Southern California have risen eight to 10 inches as the average air temperature has increased 5 degrees.

In the past 50 years, statewide temperatures have warmed during winter and spring. Lower Sierra Nevada snow levels have dropped. And snowpack -- which supplies the state with water during dry spring and summer months -- has melted up to four weeks sooner.

In addition, the annual number of 100-degree days in the San Fernando Valley has doubled since 1949, according to an unpublished study by the Jet Propulsion Laboratory.

Through the 1970s, the Pierce College weather station in Woodland Hills recorded on average 17 days when the mercury soared above 100 degrees. But between the 1970s and 2005, that average had shot up to 31 days a year.

``When you think of how hot our summers already are, it has important implications for our water supply, because a lot of that comes from snowmelt,'' said Helen Cox, professor of geography and atmospheric sciences at California State University, Northridge. ``Water supply is going to be a big challenge. What snow that does form will melt earlier, will run off into the ocean and there won't be a year-round supply.''

Snowpack levels were recorded at 43 percent in California on Friday, down from 59 percent in January, said the state's Department of Water Resources. Officials said it is too early to declare a drought.

And there are other clues to how the heat already has had an effect on the region:

Southern California earned the distinction as the region with the worst overall air quality for the third time last year, with 86 days of unhealthy air.

The risk of wildfires, which now cost the state $800,000 a year, would increase by as much as 55 percent, with a further reduction in air quality.

Late spring stream flow could decline by up to 30 percent, with California agriculture -- now worth $30 billion -- losing as much as 25 percent of its water supply.

Higher temperatures could increase energy demand by 20 percent. At the same time, declining snowmelt could decrease hydropower production up to 30 percent.

Scientists, however, say much of nature's response to climate change is still unknown.

``Despite the level of certainty in this report, there is a great deal to learn about how the Earth responds to a forcing,'' said Lowell Stott, associate professor of earth sciences at the University of Southern California.

``The fact is, if you look back in time, it is indeed true the Earth has experienced a lot of climate variability. So what is happening today is not unusual. What is unusual is the rate that it's happening.''

And to those who believe that, one day, the San Fernando Valley may be home to beachfront properties because of the rising water levels, well, some say it may come at a price.

``That's not too much of a joke if you relate it to New Orleans,'' said Cox, the geography professor from CSUN.

susan.abram(at)dailynews.com

[phone]