The issue of global climate change has raised a number of questions, ranging from sharp rises in termperature to how can humans change their lifestyles to be more environmentally friendly.

Now, two UW scientists, Drs. Jeremy Littell and Nathan Mantua have teamed up with Idaho State professor Dr. Matt Germino and UW alumna Dr. Lisa Graumlich to study the changes in tree lines with regards to global climate change.

"The big question," Germino said, "is how will forest boundaries change with global climate change?"

Studies from the Climate Impacts Group (CIG), an interdisciplinary group researching impacts of natural climate variability and global climate change in the Pacific Northwest, reported that increased precipitation and a change in the normal weather patterns are expected.

Global average temperature is projected to increase 2.7 to 10.4 degrees Fahrenheit — 1.5 to 5.8 degrees Celsius — by 2100, compared to 1990 temperatures, according to reports from the Intergovernmental Panel on Climate Change (IPCC) in 2001.

As the temperature warms, it is expected that, at certain levels, some tree species will be able to grow at a higher altitude.

"More recently, we have been able to look at changes in tree establishment, where trees germinate and continue to grow," Littell said. "We've noticed that there are a lot of younger trees and only a few older trees at upper tree lines. So, it looks like there is an increase in establishment at some tree lines."

Though this is beneficial for trees, other alpine vegetation, and the animals that rely on it, may suffer.

"Some argue that tree lines should not be sensitive to climate change, whereas others argue that they may be among the most sensitive vegetation boundaries," Germino said. "...But this is not an easy question, which is why the research is needed."

This is a unique research project because it combines a variety of specialists to study how the trees are reacting to the climate changes.

"With all of us working together, we have the ability to study how trees grow, where they grow, and then the ecophysiological controls on how they respond to climate change," said Littell. "One reason we were funded to do this project is because nobody is looking at all of those aspects together over such a large area."

Because this research is in its beginning stages, the scientists are unsure what findings will develop.

"We hope to understand how the interaction between variability in climate and biological systems structures ecosystems in mountain environments," Littell said.

Though changes in tree lines are certain, whether or not these alterations can be prevented is unclear.

"It is unlikely that we can stop the changes that are going to occur in the West," said Littell. "We can't stop this. Instead, the way you get at this is by asking 'How do you influence climate change?'"

Though the process of global warming and climate changes may be inevitable, researchers are certain that human effort can make a difference.

"Slowing green house gas emissions can, and should occur," Germino said. "Scientists at UW and elsewhere have repeatedly shown that our opportunity to prevent the level of CO2 in our atmosphere from vastly exceeding any prior levels is now."

Reach reporter Celia Hunko at news@thedaily.washington.edu