California's Resources

The Climate Challenge: Scripps Addresses A Growing Threat To California's Resources

Greenhouse gas emissions caused by human activities are widely believed by scientists to be responsible for a number of observed climate changes, and a number of them have already been witnessed in California.

Sierra Nevada snowmelt takes place one to four weeks earlier in spring. Less precipitation falls as snow and more as rain. Rising sea level is changing the profile of the state's coastline and estuaries.

Climate conditions that favor the spread of parasites such as bark beetles have killed thousands of trees in California forests. An increased likelihood of hotter, drier conditions has intensified demands on water and energy supplies and increased the risk of wildfires. Analysis done at Scripps Institution of Oceanography at UC San Diego and other research centers projects that, by the end of 21st Century, the snowpack in the Sierra Nevada could diminish by 70 to 90 percent if emissions levels follow the higher pathways amongst the scenarios that have been projected.

Even with the lower levels of these observed climate trends, however, California would still face increased demand for natural resources. The state Department of Finance now estimates that more than 50 million people will live in California by 2050 compared with a current population of 36 million. Thus, the decisions that state resource managers make in coming decades will be vitally important no matter what climate scenarios become reality. For several years, climate researchers at Scripps have been not only making fundamental field observations but have been working with city, state, and federal agencies to formulate the most prudent possible decisions based on those observations.

For instance, Scripps researchers are playing a key role in assessing potential climate change impacts on a range of California resource sectors, including water resources, agriculture, fire, coasts, and human health. Scripps and USGS researchers are providing vital information and projections of possible climate change to the CALFED Bay-Delta Program, a collaboration among 25 state and federal agencies to improve water supplies in California and the health of the San Francisco Bay/Sacrament-San Joaquin River Delta. The Integrated Forecast and Management (INFORM) project led by the Hydrologic Research Center, working with Scripps researchers, assists Northern California reservoir operators using a new forecast system to guide decisions governing the storage and release of water from major reservoirs.

Scripps climate scientist Daniel Cayan leads two projects that are centered around understanding climate impacts in the California region. The California Applications Program, sponsored by the National Oceanic and Atmospheric Administration (NOAA), is a part of NOAA's Regional Integrated Science and Assessments centers, aimed at providing better climate information to California decision makers. The California Climate Change Center, sponsored by the California Energy Commission, is working to clarify climate change impacts in the state. Both of these research projects engage a set of researchers at Scripps as well as experts from other universities, government agencies, and non-governmental organizations.

Besides its modeling and analytical work, the Scripps Climate Research Division is collecting data to conduct regional climate assessments. Cayan's research group at Scripps currently operates a network of hydrological and meteorological stations in key watersheds of the Sierra Nevada as well as along the Santa Margarita River north of San Diego. The stations include components such as sensor packages submerged in stream beds to measure water level variations and meteorological instruments to track temperature, barometric pressure, and other atmospheric conditions. These observations are used to monitor changes, understand attendant processes, and validate models that are used to foresee possible future changes and impacts.

The Scripps climate group is working on a number of projects to assess potential impacts of climate warming, including drought, extreme weather, detrimental air quality, and sea level rise. Besides helping to advance climate science, these have very practical objectives that are aimed to help the state of California negotiate the challenges that global climate change will bring to California.