Global warming is a big thing. The pine beetle is an exceedingly small thing. But when the two are combined, it means one thing for North Carolina's pine forests -- trouble.

Higher global temperatures will likely bring milder winters to North Carolina, allowing pine beetles to hatch more offspring and possibly expand their killing zones. The most recent beetle outbreak, which ended in 2001, cost the Southern lumber industry $1 billion. One U.S. study predicts up to seven times more trees dying in a warmer climate.

The beetle threat is part of a phenomenon that could affect a wide range of North Carolina staples. Rising temperatures could intensify the activity of pests, play havoc with pollination cycles and weaken the natural defenses and migratory patterns of sea life, which have developed over millennia of cooler temperatures.

There is still debate over how much of the change in temperature is due to man-made carbon dioxide and how much comes from the natural cycles of weather. But international climate scientists predict that Earth might warm between 3.5 degrees and 8 degrees by the end of this century due to heat trapped by man-made greenhouse gases.

Scientists are exploring how more heat would alter North Carolina's landscape and its bounties.

"You don't want to scare people, but you're foolhardy not to do everything you can to prepare," said Louis Daniel, director of the N.C. Division of Marine Fisheries. He counts the effect of climate change among his top long-term concerns for North Carolina's coastal waters.

Beetle attacks feared

After watching insects attack trees for 30 years, entomologist Fred Hain grew alarmed the last time drought struck North Carolina. Southern pine beetles badly damaged mountain forests in the hot, dry weather, felling trees that often resist them.

As it gets warmer, there could be more trouble. In his laboratory at N.C. State University, Hain and his team hope their findings on the beetles will help timber growers fight outbreaks.

Southern pine beetles, small as uncooked grains of rice, attack en masse, boring through a tree's bark, mating there and laying eggs. They dine on nutrient-rich phloem, tissue beneath a tree's bark that carries water and food from the crown to the roots. The beetles also carry fungus under the bark, which worsens the damage.

As the beetles eat the phloem, they dig grooves into the tissue. This can girdle a tree, blocking food from its roots and killing it.

"Even the healthiest tree can be killed if enough beetles attack it," Hain said. One irony of climate change is that it could extend the growing season of trees in the South, providing beetles with more fuel for multiple life cycles each year.

Hain wants to find out just how well the bugs do attacking white pine, a tree that appeared more vulnerable to pine beetles during North Carolina's last drought. That could help his team produce a computer model that predicts how, in warmer weather, the pest would perform in a real forest, particularly while trying to expand its terrain.

Birch McMurray is glad someone is trying to figure that out. He tends 150 acres of family timber forest in Polk County that was attacked by southern pine beetles eight years ago.

"I think it could totally wipe out the pine forest if we have enough stress from weather and the trees are planted thick and under stress," he said. Landowners cut so many trees last time that the value of lumber plummeted.

"There were acres and acres and acres," McMurray said. "People would give them to you to cut them."

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