Things are heating up

BNL scientist makes national headlines with study on global warming

By Anna Gustafson

Brookhaven National Lab scientist Stephen Schwartz is afraid of the world his grandchildren will inherit.

"I'm very concerned about the world my grandchildren will live in," said Mr. Schwartz, who is currently studying climate change. "There could be an increase of four to eight degrees in the next century, and that's huge. The last time there was a five-degree Celsius decrease was the last ice age. An increase of eight degrees Fahrenheit would bring change unprecedented in the last half-million years."

Scientists aren't sure exactly what such a change in temperature could bring, but one of the "big possible consequences" is an increase in sea level, Mr. Schwartz said.

"It's not out of the question that the ice sheet on Greenland could melt, and the consequence of that is the sea level would rise," he said. "The shoreline on Long Island would move inland by two to three miles."

Mr. Schwartz, a senior scientist at Brookhaven National Laboratory, is one of about 50 scientists studying climate change at the lab. Most recently, Mr. Schwartz published a study in June that has resulted in sensationalist headlines across the country.

A report on Fox News introduced the study by saying, "Skeptics are increasingly certain the [global warming] scare is vastly overblown," and other news sources said Mr. Schwartz's study debunked the notion that global warming is a force with which humanity needs to contend.

This, he said, was not what he was trying to prove at all. Global warming is a very real reality, he said, and his study spells that out -- though in a different manner than those carried out by other scientists and organizations.

Titled "Heat Capacity, Time Constant and Sensitivity of Earth's Climate System," the study used observations of Earth's temperature and the oceans' heat content to determine the planet's sensitivity to increasing levels of carbon dioxide, which results from fossil fuel combustion.

In his study, he explains that the Earth could be only about one-third as sensitive to a doubling of carbon dioxide as predicted by the latest report by the Intergovernmental Panel on Climate Change. Mr. Schwartz estimated a rise in the Earth's global mean surface temperature of 1.1 degrees Celsius versus the IPCC's estimate of 2 to 4.5 degrees Celsius for a doubling of carbon dioxide.

Regardless of the difference in temperature, Mr. Schwartz said this increase is not to be taken lightly, nor does it imply climate change is a false claim to be sniffed at.

If his estimate is correct, "it means that the climate is less sensitive to [carbon dioxide] than currently thought, which gives some breathing room," said Mr. Schwartz, who has a Ph.D. in chemistry and has been at the Brookhaven Lab for about three decades. "But a lower sensitivity does not solve the long-term problem that would result from continued buildup of [carbon dioxide]."

Carbon dioxide can play a menacing role in climate change, Mr. Schwartz said -- which he attempts to explain to "youngsters" during the lab's weekend programs for children.

"I'll ask them who got here by car, and I'll tell them there's five pounds of carbon in a gallon of gasoline," he said. "That goes into the atmosphere as carbon dioxide. I tell them to imagine they have grandchildren and imagine their grandchildren at their grandparents' age. I explain half of the five pounds of carbon put in the atmosphere today will still be in the atmosphere when their grandchildren are the age of their grandparents. When we burn carbon, we get the benefit of the motive force today; it heats our homes and powers our electricity, and we leave carbon in the air for the grandchildren to deal with."

Currently, Mr. Schwartz is studying the role of atmospheric aerosols -- basically particles in the air that create what looks like smog or air pollution to the human eye -- in climate change.

The aerosols "have a cooling influence on the climate," he said. "But that's not good because it's masking the true magnitude of the greenhouse effect, so the warming taking place is probably greater than we're actually experiencing."

It could be decades before scientists really understand to what degree aerosols -- which are largely associated with fossil fuel combustion -- impact climate change, but Mr. Schwartz said the influence could be substantial and preventing scientists from correctly assessing the damage of the greenhouse effect on Earth.

Ultimately, Mr. Schwartz said, the goal is not only to understand climate change but to have policy-makers be able to act on the findings in order to deter further environmental damage.

"We want the research to be at hand that says this greenhouse effect is real, and that would allow better-informed decision making," he said.

Indeed, the greenhouse effect is real, Mr. Schwartz said, and humanity needs to curb their own actions or the children living today could be facing a very dire situation by the time they're seniors.

"People have to realize that decisions being made today will affect their lives, their children's lives and their grandchildren's lives," Mr. Schwartz said. "It's our responsibility to think of these things now to turn things around."