UCSD offers understanding on global warming issues

UCSD, considered to be one of the most prestigious research institutions in the country, has been acknowledged for its breakthrough research in global warming study thanks to some of the most dedicated atmospheric scientists in the field. Most recently, research at UCSD has focused on changing weather patterns and the particles and gradients affecting such changes. In the ongoing debate on the causes of global climate changes, evidence found by these scientists is considered to be the most convincing.

Concern over global warming dates back to Roger Revelle’s discovery of how sea water controls the amount of carbon dioxide and greenhouse gases in the atmosphere. Revelle’s discovery caused a massive reorganization within the fields of environment and earth sciences. Carbon dioxide in the atmosphere contributes to global warming by making it more difficult for solar radiation to escape into space, causing an increase in air pollution and rising sea levels due to melting glaciers. Changes in weather patterns and temperature in certain areas have also verified that the temperature of the atmosphere has increased. These problems, in part, are due to the emission of aerosols released from cars, trucks and coal-burning power plants. Fossil-fuel use in the United States is responsible for more CO2 emission than any other country, and though the amount of fossil fuel is finite, there is still plenty left to cause more irreversible damage to the atmosphere.

Charles David Keeling, a professor at the Scripps Institution of Oceanography and an expert on the way carbon moves through the planet’s ecosystem, was the first to measure CO2 in the atmosphere on a continuous basis. He first started measuring amounts of CO2 in 1958, and the concentrations have increased consistently ever since. Researchers at UCSD agree that Keeling’s findings are alarming; they provide credible evidence that increased CO2 counts may be responsible for the warming of the atmosphere. In addition, scientists agree that CO2 is the most significant man-made, controllable gas.

At UCSD, researchers have concentrated on particles, or aerosols, in the atmosphere, and how they are distributed, transported and developed. Many people do not consider the role of clouds and how they can contribute to global warming.

“Clouds can act like a thermostat and cool the atmosphere or they can act like a blanket and warm the atmosphere,” meteorologist and SIO professor Richard Somerville said. “Clouds can contribute to the greenhouse gas effect and cause the atmosphere to warm up even more.”

Clouds reflect about 30 percent of sunlight back to the sun while the Earth absorbs 70 percent. Somerville has been involved in cloud research, which entails studying the microphysics of clouds by flying an airplane through a bank of clouds, measuring temperature, barometric pressure and humidity. These data are in turn used to measure water content, distribution of particles and ice crystals to predict global warming effects.

One further method of global warming research at UCSD is the collection of ice cores, taken from layers of ice some 30 feet deep that are more than 5,000 years old. By measuring the amount of CO2 trapped in bubbles in the ice, scientists are able to determine the CO2 content of the Earth’s atmosphere during different time periods.

“These studies show an increase in CO2 levels in the ice between the Ice Age periods,” SIO director Charles Kennel said. In addition to this, past research by SIO researchers Jeff Severinghaus and John Berger have concentrated on how the climate has changed in the past and how this knowledge can be used to determine the future of the environment.

Mark Thiemens, dean of the division of physical sciences and professor of chemistry and biochemistry at UCSD, studies the effects of global warming by cutting a 30-feet-deep snow pit to look at climate change with high temporal resolution. Last year, he dug up 27 tons of snow from the South Pole and analyzed samples to figure out the extent of change caused by CO2 emission. The purpose of his research is to measure greenhouse gases from different regions on the globe to get an idea of how these areas affect one another.

“The deeper the snow, the further back in time we get,” Thiemens said. “We are trying to understand the whole planet.”

An increase in the global temperature can affect also weather patterns.

“As the average temperature increases, rain moves up in altitude,” Kennel said. “Predicted for 2050 or 2060, half of the winter snow pack will be gone in the Sierra Nevada and snow will fall as rain.”

As this effect becomes more prevalent, the run-off in California will decrease with the depletion of the snow pack, requiring major changes in the way the state manages its water and irrigation.

Improvements in the accuracy of weather forecasting can be attributed to breakthrough research on climate’s dependency on the thickness of clouds — sometimes measured to the nearest micrometer — and how they can affect the atmosphere.

“Working with cloud microphysics in incredible detail can assist scientists in using clouds in weather prediction models instead of humidity levels to help forecast rain,” Somerville said.

Understanding how aerosols are transported from one region to another can help scientists further comprehend how these particles can affect different areas. The ocean, for example, has been examined in some areas and researchers have determined that the ocean temperature is increasing due to aerosols’ greenhouse-gas influence. The presence of aerosols has led to a change in the biodiversity of plants and has taken a toll on the health of the population. According to Thiemens, “60,000 people in the U.S. die every year from breathing aerosols and particles.”

Global warming is a well-known and controversial issue; skeptics argue that research is unnecessary and that the time and money should go toward more relevant geological issues such as earthquake detection or oceanography. According to the experts at UCSD, however, global warming should not be ignored, nor can it afford to be.

“The damage has been done, but the longer people wait to do something about it, the more severe it is going to get,” Kennel said. “We need to limit CO2 to twice or three times the current level.”

Somerville agrees that global warming is destructive.

“It will increase the chance of drought years and the water we drink will be scarce because there will be less snow,” he said.

Even though global warming research at UCSD and SIO is considered innovative, each expert feels that there is still a long way to go before global warming is ever considered to be under control. For now, some of the most advanced computer models available are being used to assist researchers in collecting and examining data. These global climate models will help scientists better understand the behavior of the atmosphere and the environment in terms of global warming.