Drought

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March 13, 2012 | 9:13 AM | By

This Winter Looking Like Fourth Warmest for Lower 48

Could be second-driest winter on record for California, Pacific Northwest

Craig Miller

Rain comes late to Northern California: A March storm front hovers over San Pablo Bay, north of San Francisco.

Last week’s State of the Climate report issued by the National Oceanic and Atmospheric Administration found that this winter is stacking up as the warmest since 2000 and the fourth warmest on record in the contiguous United States.

According to NOAA, 47 of 48 states experienced above-average temperatures in the period between December and February, with the greatest increases seen in the Northeast and Midwest.

Only New Mexico saw below-average temperatures. Continue reading →

FILED UNDER: The Science, Drought, temperatures, weather
February 1, 2012 | 2:37 PM | By

Snow Survey May Portend a Dry 2013

Skimpy Sierra snowpack may take a while to show up in water supplies

snow Tahoe Sierra California water

Tyche Hendricks/KQED

After a record dry December, there's finally snow on the ground near Soda Springs, at Lake Tahoe.

This morning’s snow survey (PDF) didn’t turn up any big surprises. As remote sensors foreshadowed, water content in the Sierra snowpack is 37% of normal for this time of year, and less than a quarter of the average for April, which is when the snowpack is usually at its peak before it begins melting and filling up California’s reservoirs.

What’s worrisome about that, according to Jeanine Jones, Interstate Resources Manager at the Department of Water Resources, is that about half of California’s annual precipitation typically falls between December and February, months that are mostly already behind us. “So where we are this year is: November was dry, December was close to record dry, January was maybe half of average,” Jones told me. “And currently the forecast for the first  ten days or so of February is essentially dry.” Continue reading →

FILED UNDER: Water, Drought, reservoirs, Sierra Nevada, snow survey
January 31, 2012 | 2:41 PM | By

Drought Is in the Eye of the Beholder

Are we in one? Water officials say the answer is “Yes and No”

NOAA

How do you define a "drought?"

As state surveyors trudge into the mountains this week for the season’s second official survey of the Sierra snowpack, the auspices aren’t good. Remote sensors currently show that statewide, water content is averaging just 38% of the average for this date, and less than a quarter of what water managers would hope to see on April first — just two months away.

Consequently, the “D-word” is being nervously bandied about. Are we in a drought?

The state’s newly revamped Current Water Conditions website takes on the question with a definitive “Yes and no.” Drought status, it says “can be very different depending on your location.” Continue reading →

FILED UNDER: Water, Drought, snowpack
December 14, 2011 | 4:37 PM | By

CSI Colorado: Sudden Aspen Decline Post-Mortem

Droughts kill trees — but until now scientists didn’t know the root of the problem

sierrian/Flickr

Aspens live at high elevations in the Western United States, including in California's White Mountains and Sierra Nevada.

Throughout the West, aspens are quaking for good reason.

About 17% of the aspen in the Colorado Rockies have died in the last decade. That’s about one in every six trees. The widespread die-off, called sudden aspen decline, began after a severe drought and heat wave. So people studying the trees knew that’s what triggered the deaths, but they didn’t know what exactly killed the trees.

William Anderegg, a grad student at Stanford, with help from a team of scientists there and at the University of Utah, has zeroed in on the culprit, and describes the work in a paper published this week. There were two working theories: failures in photosynthesis, which would mean less food for the tree; or damage to the roots, which would mean less water. Anderegg found it was the roots.

Continue reading →

FILED UNDER: The Science, Drought, forests
December 14, 2011 | 10:09 AM | By

Take Your Pick: Wetter, Drier, and Hotter for California

New science forecasts include everything except moderation

Craig Miller

Scientists say there's a little bit of everything on the horizon for California -- except maybe funds to study it.

Two days before Governor Jerry Brown hosts his own conference on “Extreme Climate Risks and California’s Future,” scientists and a smattering of state and local officials spent a rainy Tuesday at Scripps Institution of Oceanography in La Jolla, talking about just that.

It began with calls to keep the funding for statewide climate research. Sacramento legislators may be looking at cutting money to the Public Interest Energy Research (PIER) program in particular, and California Energy Commission vice chair James Boyd told the crowd “all is not well.”  He said that research funding is “under assault again” with the weak economy used to question the focus on climate at a time when predictions are becoming more severe. Continue reading →

FILED UNDER: The Science, Drought, extreme weather
July 7, 2011 | 6:14 PM | By

Two-Year Drop in California Carbon Emissions

PG&E substation near San Jose. The drop in emissions applied to both power generated in California and imported from neighboring states. (Photo: Craig Miller)

If you’re ready for some good news on the climate front: California’s carbon emissions from power generation dropped in 2009 and 2010.

That’s according to a new analysis from Thomson Reuters’ Point Carbon that looked at power generated here in California, as well as electricity imported from out of state.

According to the report (available by subscription only), emissions were down 12% over the study period. Part of the drop, not surprisingly, was due the global recession and the state’s slowed economy in 2009. But the study found that even when the economy started growing again, emissions continued to decline.

Sound mysterious? Not really, according to study co-author Ashley Lawson. Continue reading →

FILED UNDER: Power, Water, Drought, Emissions, hydropower, Power
June 9, 2011 | 4:56 PM | By

Forget this Winter: Western Snowpack Shrinking

By Alyson Kenward

A new study finds large losses of springtime snow cover in the West in recent years, raising concerns about water supplies.

Spring snowpack in the West is an essential water resource, particularly in Southwestern states that are prone to summer drought, like California, Nevada, Arizona and New Mexico. (Credit: Wolfgang Staudt on Flickr)

This spring, from the Pacific Northwest and Sierra Nevada, to the Northern Rockies, western mountain ranges were more than just snow-capped – they were buried in the white stuff. In fact, many locations still have more spring snowpack than has been seen in decades.

Head south across the 40th parallel, however, and things are dramatically different. While there is still above average snow throughout the Sierra, a relatively snow-less winter and spring has left much of the Southwest in a drought that has fostered record wildfires. Already local officials are worried there won’t be enough water to get through the summer months ahead. Continue reading →

FILED UNDER: The Science, Water, Drought, global warming, Sierra Nevada, snow, snowpack, Temperature, Water
June 6, 2011 | 7:44 PM | By

Running Drier: The Colorado 50 Years Out

A new federal study says the Colorado River may carry 9% less water by 2060.

Lake Mead, the Colorado River's largest reservoir in May, 2010 (Photo: Gretchen Weber)

The Colorado River is a critical source of water for more than 30 million people throughout the western United States. California alone gets more than a trillion gallons of water each year from the Colorado. But over the years, recurring droughts and the growing demands of urban populations have stressed the river system, which the Bureau of Reclamation now characterizes as “over-allocated.”  In efforts to plan for the region’s future water needs, the agency, in collaboration with Western states, has undertaken a two-year study to look at what lies ahead for the river and the cities, farms, and families that rely on it.

On Monday, the agency released the first interim report of the “Colorado River Basin Water Supply & Demand Study,” which projects changes in the river’s flow under four different scenarios. A model that incorporates predicted impacts of climate change shows a nine percent reduction in the Colorado’s flow within 50 years.  The study also projects more frequent and more severe droughts throughout the system. Continue reading →

FILED UNDER: Government & Business, The Science, Water, Colorado River, Drought, Water, water supply
March 30, 2011 | 5:21 PM | By

CA Drought Lifted, Snowpack at 15-Year High

Governor lifts drought declarations from 2008, 2009

Snow removal near Mt. Lassen. (Photo: KNVN Chico-Redding).

Frank Gehrke summed it up: “Well, it has been a really crazy winter,” said the state’s chief surveyor of the Sierra Nevada snowpack.

Statewide averages from the season’s fourth survey Wednesday, shows water content at 165% of normal for April 1.

The latest survey shows statewide, water content of the Sierra snowpack is 165% of normal. Gehrke says it’s been about 15 years since there’s been this much snow on the ground at this point in the season. Earlier this month, some locations were reporting total seasonal accumulations equivalent to the height of a six-story building. Continue reading →

FILED UNDER: Water, Drought, sierra, snowpack
September 6, 2010 | 8:12 PM | By

The Science of Reconstructing Past Climate

To find out what tree rings are telling us about droughts in the Colorado Basin, and to get some current perspective on the current eleven-year drought in the region, listen to my radio story for The California Report and view the slide show of my journey to the region. — Gretchen Weber

With cores from trees like this one, scientists have been able to reconstruct more than 1,000 years of climate history in this region. (Photo: Gretchen Weber)

Abbie Tingstad is a paleoclimatologist whose doctoral work at UCLA involved reconstructing climate in the Upper Colorado River Basin, using tree rings and lake sediments.

By Abbie Tingstad

Unlike biology, chemistry, or most mainstream sciences, it’s hard to envision what someone who studies paleoclimatology actually does. I run into a lot of blank stares at dinner parties. So I’ve started describing the field as “climate forensics.”

Paleoclimatology and forensics of the Law & Order or Bones variety share the basic goal of reconstructing something that has happened in the past. In the latter, of course, the sequence of events that led to a crime is put together. In the former, researchers identify past variations in climate.  These sciences also have quite a lot in common when it comes to the basic methodology: Continue reading →

FILED UNDER: The Science, Water, Colorado River, Drought, paleoclimate, tree rings