The Science

Latest research from the field and the lab


Bay Area Landscape Likely to Come Up Short on Water

Facing the difference between how much water plants need, and how much they’ll get

Scientists are looking at climatic water deficit, the water plants need but don't have.

We hear a lot about how climate change will affect rainfall in California, but climate scientists are increasingly looking at a new indicator: water deficit.

“Climatic water deficit” relates to how much water plants need to survive. “It’s the difference between what a plant would use if it had the water and what is actually available,” Alan Flint, research hydrologist with the US Geological Survey, explained on Wednesday at the North America Congress for Conservation Biology.

The value combines temperature, rainfall, the soil’s capacity to hold water and how plants use water. In agriculture, farmers irrigate their crops to make up the water deficit, but plants in the natural world aren’t so lucky. Continue reading

Dry Weather Boosts Odds of Extreme Heat

A new study finds that drought in one month increases the likelihood of heat in the next


As soil dries, more of the sun’s energy goes into heating the air directly, rather than evaporating moisture from the ground.

Droughts such as the one currently gripping a majority of the U.S. may dramatically increase the odds of extremely hot days, a new study found. The study, published in Proceedings of the National Academy of Sciences, explores a dynamic that is playing out right now across the country, particularly in the Great Plains, where the severe drought is priming the atmosphere in favor of an above-average number of extremely hot days.

This occurs because of feedbacks between the ground and the air: as the soil and vegetation dry, more of the sun’s energy is able to go into heating the air directly, rather than going into evaporating moisture from plants and the soil.

With drought conditions intensifying during mid-summer, the study suggests that the U.S. may be in for particularly brutal Dog Days of August. Continue reading

Preserving Biodiversity in the Age of Climate Change

The dean of conservation biology has a message for young scientists: Get out of the lab

Hundreds of scientists are gathered in Oakland this week to share ideas on how to stem the tide of extinctions among plants and animals. On opening night of the inaugural North American Congress for Conservation Biology, they got an earful from Michael Soulé, professor emeritus at UC Santa Cruz, founder of the Wildlands Network and the Society for Conservation Biology. Considered the “father” of conservation biology, Soule is concerned that the work he started is getting bogged down in the lab. I sat down to talk with him at the conference. This is an edited version of the interview.

What were the biggest problems when you started working on conservation biology?

Coastal sage scrub and riparian habitat on the San Diego Refuge.

I was a kid naturalist in San Diego. I went around collecting things and going to tide pools and playing in the chaparral, the coastal sage scrub. Those places are gone now; they’ve been bulldozed and they’re now housing developments. So I saw with my own eyes, and was gradually more and more horrified to see, everything I loved disappear, bulldozed.

Later, in the late ’70s and early ’80s, I recognized that human population growth was a tremendous factor in changing and shrinking habitats all over the world. And we recognized that pollution — in those days it was DDT — was a big factor in causing the disappearance of brown pelicans, for example, on the West Coast. Continue reading

After Two Years of La Niña, El Niño May Be on the Way

The climate pattern usually causes wetter weather in California

By Andrew Freedman

In 2010, a series of strong storms linked to El Niño caused major flooding in Southern California.

If you thought the first six months of the year were chock full of weird weather events, just wait — according to climate scientists there is an increasing likelihood that El Niño conditions will soon develop in the tropical Pacific Ocean. El Niño events, which are characterized by an area of unusually warm sea surface temperatures in the tropical Pacific Ocean, can have a huge influence on global weather patterns. Its effects on the U.S. tend to peak during the winter.

The U.S. has already had a record warm January-to-June period, and has already had two extremely rare heat waves this year, one in March and the other in mid-June to early July. Entering mid-summer, drought conditions are covering 56 percent of the lower 48 states, a record drought extent in the 21st century. Continue reading

Why Hasn’t California Been Hit With This Summer’s Extreme Heat?

As the rest of the country roasts, California has enjoyed a moderate summer

California has not experienced the extreme heat much of the rest of the country has this summer.

For more than a week, record-breaking temperatures have been baking the Midwest and East Coast. But while cities in other parts of the country broke and tied records for the hottest Fourth of July, in San Francisco I bundled-up in a couple sweaters and watched the fireworks through the fog. Which is typical. Overall, it’s been an average summer here in California, at least temperature-wise.

“At June around the state, most places were fairly close to normal, or a degree and a half below normal, so not any real extremes,” Jan Null, a meterologist with Golden Gate Weather Services, told me. “We’ve stayed in the mild, in-between area. It was not a particularly cold winter, and not a particularly hot summer.” Continue reading

Talking Climate, Online in Real Time

Stanford professor is using new tools to hang out and chat

Stanford professor Noah Diffenbaugh is using real time, online video chat to engage the public in discussions of climate science.

Noah Diffenbaugh, an assistant professor in the Department of Environmental Earth System Science at Stanford, has focused largely on climate variability and the influence of humans on the global climate system. Lately, he’s also being spending time in the cloud.

In April, he launched an online discussion forum called Hangouts on Air, in which participants from anywhere around the world (with a broadband connection, that is) can participate in real-time online discussions about climate.

Participation has been limited in these first months, but Diffenbaugh says the model holds promise for engaging the public on the complex, contentious and rapidly evolving issues in climate science. He agreed to answer some questions for Climate Watch. Continue reading

Sea Level Rise Will Hit Calif. Harder Than Rest of the West

New study zeroes in on sea level rise on the West Coast, finds variation based on location

San Francisco International Airport could be underwater within the next few decades.

By 2030, sea levels on most of California’s coast will be five inches higher than ten years ago. By 2100, three feet higher. That’s according to a new report by the National Research Council. The study arrived at numbers that aren’t far from previous projections of sea level rise, but other research has been on a global scale, and this one focused specifically on the West Coast.

“What was surprising to me was Oregon and Washington being so different,” Robert Dalrymple told me; he’s a professor of civil engineering at Johns Hopkins University and chair of the Committee on Sea Level Rise in California, Oregon, and Washington, which wrote the report.

Sea level rise happens at different rates at different places. Continue reading

Zooming in on L.A.’s Warming Climate

First-of-its-kind study breaks down predictions for 27 L.A. microclimates

Green roofs like this one at Vista Hermosa City Park are part of the solution for Los Angeles

Listen to the radio version of this story on The California Report.

The City and County of Los Angeles now have customized climate predictions, thanks to a new UCLA study that took global climate science and made it local. A UCLA supercomputer ran for eight months to downscale 22 different global climate models, distilling them into a surgically precise look at L.A. County and beyond. It’s a new kind of Hollywood close-up and it’s a sobering one: temperatures will rise in areas of Los Angeles County by an average of 4 to 5 degrees by mid-century.

Commissioned by the city of Los Angeles, funded by a U.S. Department of Energy grant and conducted by UCLA’s Department of Atmospheric and Oceanic Science, the study focused on forecasting for the metro area between 2041 and 2060. But instead of relying on the global climate model grids that use data from 100 kilometer-square cells of the earth’s surface, the UCLA team’s “quintillion-plus” calculations — yes, that’s with 18 zeros — zoom in to a resolution of 2 square kilometers, just over a square mile.  So instead of data and forecasting for the whole county, you can talk specifically about climate change for Corona, for example. Continue reading

Burning For Solutions in an Increasingly Fire-Prone West

Fire management in the West: A dangerous game of Whac-a-Mole

U.S. Fish and Wildlife and Cal Fire crews fighting a wildfire near San Diego. Federal and state budget cuts have greatly reduced California's wildland fire resources.

As more than 400 firefighters attack a 2200-acre wildfire in Riverside County, and huge fires continue to burn in Colorado and the Southwest, recent studies have projected that the western U.S, wracked by an increasingly hot and dry climate, will experience more frequent and intense fires in the near future.

But pinpointing just where and when those larger, hotter, more destructive fires will occur — in the near term —  is a much different sort of science.

The job of seasonal wildfire forecasting, it turns out, falls to an agency called the National Interagency Fire Center. Each month, the Boise-based NIFC, a collaborative of eight federal agencies, including the National Forest Service, Bureau of Land Management and National Weather Service, issues its Wildland Fire Outlook [PDF], which offers a year-to-date tally and projections of acres burned along with a comprehensive look at where fire conditions are ripe.

Ed Delgado, manager of the NIFC’s Predictive Services program, says his team looks at a number of factors including snowpack, drought, fuel conditions (that is, the amount of dry vegetation available to burn) and periodic climate variations such as El Niño and La Niña.

This year, the Great Basin, Rocky Mountains and northern Sierra are in the “above normal” category for fire, said Delgado, because of prolonged drought, low snowpack and high fuel-loading of of dead timber and grasses. “We had a very limited snow in the deserts of the Great Basin and that allowed grasses from previous years to remain standing tall,” said Delgado.  “This added to the fuels available to burn.”

As for California, the NIFC has predicted that the central Sierra and the Coastal Ranges will come into above average fire danger from July to September, with fires above 8,000 feet more likely than in recent seasons. (Richard Minnich, a fire ecologist at the University of California, Riverside, has predicted low fire risk at low elevations in the southern half of the state because of scant winter rainfall that killed grasses before they deposited seeds.)

Delgado says he has personally seen fire season come earlier by a matter of a few weeks in parts of Utah and Nevada. But the NIFC’s forecasts do not examine whether such changes in seasonal fire activity – such as that in the central Rocky Mountains where the forecast number of fires (1,888) are more than double, and the number of acres projected to burn (186,083) nearly double, the June average – are the result of long-term shifts in climate, or fire suppression, grazing and other management practices that have increased fuel stores – or some combination of these ingredients.

Figuring out just how these factors contribute to fire activity, year-to-year, may be critical, especially with resources stretched thin because of deep cuts to wildland firefighting budgets at federal, state and local levels.  Earlier this month, for example, the Guardian reported $512 million in federal cuts for wildfire suppression and preparedness – an overall decrease of 12 percent since 2010. In California, governor Jerry Brown announced an $80 million reduction in the Cal Fire budget. In response, the agency downsized the number of seasonal firefighters on its rolls from 3100 in 2010, to 1700 this year, and for the second straight year has reduced staffing on engine crews from four to three. (Cal Fire faces another $60 million in trigger cuts next year if the governor’s new tax plan fails to be adopted in the November election.)

Others, however, have questioned the wisdom of allocating tens-of-millions of dollars to fighting wildfires, which once were an essential part of the natural lifecycle of forests and grasslands. As Daniel Glick, writing in Audubon Magazine last year about the proliferation of billion-dollar “megafires”over the last decade, described it:

Experts wondered if “fighting” these colossal fires wasn’t about as effective as dropping DC-10 tanker loads of $100 bills into the flames. More than three million acres have burned each year since 1999—and a 10-million-acre year is almost certainly on the horizon. As the cost of firefighting crossed the billion-dollar mark every year since 2002, another measure of “mega” began to catch policy makers’ eyes: mega expensive. The money being thrown around to douse these fires has pretty much gone up in smoke—and more than 400 wildfire fighters have died since 1987.

The fire-prone reaches of the West are faced with a daunting future. Climate change coupled increased fuel loads from periodic drought, fire suppression and pine beetle outbreaks will make fires more frequent and more intense. Declining budgets coupled with rising costs of fighting these growing conflagrations will limit the resources available to suppress them.  While fire is indeed necessary to germinate seeds and reduce fuels, suburban and exurban growth has pushed to the edges — and deep into the interiors — of the nation’s forests and rangelands. (For example, more than 800,000 structures now sit in fire prone areas amid the 31 million acres of California open space overseen by Cal Fire.) This creeping development has permanently altered the natural dynamics of forests and has made some of the best tools for preventing large wildfires – prescribed burns, for example – into highly risky propositions.

The heat is on for solutions. What are your thoughts?

Richard Muller: Yep, Still Skeptical

Tagged by some as a “convert” to global warming, the Berkeley physicist talks about his work, some of its controversial funding, and his views on renewable energy

While Richard Muller has come around on global warming, he remains skeptical toward many aspects of climate science.

The outcome of Richard Muller’s sweeping independent audit of temperature data surprised a lot of people — including him. Known as the Berkeley Earth Surface Temperature study, or BEST, the project was rooted in Muller’s own skepticism toward some of the key data underlying conclusions that the UN’s influential climate panel has drawn about global warming.

The author of two books worth of science advice “for future presidents” now concedes that “global warming is real,” but he remains skeptical about a lot of things, like:

  • The objectivity of some of his colleagues
  • The link between climate change and severe weather
  • The future of some renewable energy sources, like solar thermal and geothermal

In the video clip (below), Muller talks about the perils of accepting scientific findings at face value.

Here are some more excerpts from our recent conversation: Continue reading