REGION: State should brace for greater disasters, rising costs from climate change, experts say

California should prepare for massive storms, frequent and severe wildfires, and dwindling snowmelt, scientists at a climate conference at Scripps Institution of Oceanography said last week.

The conference showcased new research on the practical consequences of a warming planet.

Although similar events have explored the academic nuances of climate research, the conference last week highlighted the implications of warming on wildfires, water supply, energy policy and biological diversity.

It's an approach that sidesteps political debate over climate change, and places it in the realm of resource management and emergency preparedness, following an initiative by Gov. Jerry Brown, said conference organizer Dan Cayan, a research meteorologist at the institution.

"Climate change is polarizing, but when you talk about floods and fires, everyone agrees that they are huge problems," he said. "Most of this is phenomena we have seen historically. In the future, it looks like it will be amplified, both in terms of magnitude and frequency."

For instance, speaker Marty Ralph, a branch chief for the National Oceanic and Atmospheric Administration, said both droughts and floods will become more pronounced in coming decades.

Water supply may diminish as snow lines rise in the mountains, reducing winter snow packs, which act as natural reservoirs, he said. As warmer temperatures extend the growing season, plants will absorb more runoff.

"You're going to end up with less water in streams, because basically the ecosystem is consuming more of it along the way," he said.

Fierce storms could exceed previous natural disasters, straining the state's emergency resources, he said.

For instance, he said, models show increasing risk that an immense storm could strike Southern California, draw emergency responders from around the state, and then, days later, hit Northern California, to cause as much as $500 billion in damage.

"This is Katrina on steroids," he said.

Tony Westerling, a professor of engineering at UC Merced, said models show that a 10 percent increase in drought during October could raise average wildfire size by 30 percent, and increase the frequency of the biggest blazes by 40 percent.

Terry Root, a senior fellow at the Woods Institute for the Environment at Stanford University, said biological range shifts are happening now as creatures adapt to higher temperatures.

"Species are already changing," she said. "They are not sitting around waiting."

For example, a landmark 1900 survey of California fauna by biologist Joseph Grinnell found the pika, a small rabbitlike mammal, at altitudes of 7,800 feet in California mountains.

More than 100 years later, researchers found the animal had shifted to territory as high as 9,500 feet, Root said.

"All over the globe, species are moving toward the poles and moving up in elevation," she said.

However, she said, they're not moving at the same pace. So creatures that never coexisted are now sharing the same environments, with uncertain interactions, she said.

"There will be a lot of breaking down of biotic connections," she said.

High temperatures can cause birds to abandon nests, or die protecting them, she said. As saltwater intrudes on lagoons and estuaries, changes in marine microorganisms could also affect birds, as well as some of the state's most important salmon fisheries.

As warming progresses, she said, "We're going to get a lot of surprises and a lot of extinctions, too."

Michael Hanemann, a professor of environmental and resource economics at UC Berkeley, said the models used to estimate damage from climate change underestimate the risk by using aggregate temperature increases, which obscure more dramatic local spikes.

Analysis of climate change by the Intergovernmental Panel on Climate Change assumes temperature increases of 2 percent, he said, but the most populated areas of the state could see a sharper rise.

"Where the people are, where the damage occurs, it's closer to 5 percent," he said.

Some economic analyses place damage from climate change at about one-half a percent of the country's gross national product ---- far less than the cost of addressing it, Hanemann said. His studies suggest that those estimates are too low, neglecting effects on water supply, rainfall and human mortality.

"In my own work, I think the assessments of loss for the U.S. are way too complacent," he said.

A rigorous analysis of climate change data will allow regions to brace for the worst-case scenarios, he said.

"Because the largest damages are associated with local extreme events, one should think of climate policy in terms of risk assessment and risk management," he said. "It requires a political will to take this on and figure out where we're vulnerable."