'U' researchers find evidence of warming

By Lindsey Alpert

Daily Staff Reporter

As scientists continue to debate the impacts of global warming, researchers at the University have found the earth's temperature has increased about 1.8 degrees Fahrenheit in the past 500 years, a change that has negatively impacted the environment.

"About half of that temperature change has occurred in the 20th Century," geological sciences Prof. Henry Pollack said. "Thirty percent of this occurred in the 19th Century, so basically there's been an 80 percent change in the past two centuries."

Pollack, along with Shaopeng Huang, a research scientist at the University, and Po-Yu Shen of the University of Western Ontario, took temperature readings from bore holes around the world to collect their data.

Their findings were printed in the journal Nature, published yesterday.

The researchers took many of the readings from holes already dug for other purposes such as mining. They also received temperature readings from other researchers in various locations.

"We have made it known to colleagues across the world and ask them to contribute information to a global data base," Pollack said.

Readings were taken from the rocks in the upper 500 meters of the earth's crust.

"If temperatures in the atmosphere are changing, the rocks in the earth will feel it," Pollack said. "By looking at variations of temperatures in the rock, it tells us what took place on the surface in earlier times."

The earth's temperature increases because of the burning of fuels said Environmental Protection Specialist Stephan Sylvan from the Environmental Protection Agency.

"When many fuels are burned, carbon dioxide is produced, which is a green-house gas," Sylvan said. "The CO2 acts as an atmospheric blanket that lets heat in the atmosphere but not out."

Many scientists speculate that the concentration of carbon dioxide in the atmosphere will double in the next few decades Sylvan said.

Although a change of 1.8 degrees doesn't seem very large, it has a negative impact on the environment.

"Just because global temperature rises on average, that doesn't address specific extreme events," Sylvan said. "The hottest day of the year might just become that much hotter."

The negative effects due to global warming include impacts on human health, coastal flooding, water, forests and other ecological issues.

SNRE assistant Prof. Terry Root has conducted research on the impact of global warming on various species, with a focus on birds.

"A lot of species are already reacting to global warming," Root said. "Trees are flowering and budding earlier each year and the birds are migrating earlier."

Sylvan said humans are also at risk because of the increase of heat related deaths and the chance for infectious diseases to flourish due to the increase in breeding areas for the diseases.

Coastal communities might also be affected by flooding. "When global temperatures increase, you see a rise in sea level that will flood coastal areas and communities," Sylvan said. "There is a prediction that by the year 2100, there will be a 50 centimeter sea level rise which can flood more than 5,000 square miles of dry land."