Some scientists are cautioning that global warming could mean colder weather for Atlantic Canada.

Melting Arctic ice may cause cooler water to drift south and change the climate of the eastern provinces in a different way than many people would expect, said Ken Drinkwater, who worked for three decades at the Bedford Institute of Oceanography near Halifax before moving to the Institute of Marine Research in Norway five years ago.

"That's one thing that could affect a good part of the North Atlantic," Drinkwater said in an interview Monday. "It could happen."

The melting Arctic ice would alter a phenomenon known in scientific circles as meridional overturning circulation, where warm ocean currents move north and colder currents move south, maintaining a moderate climate on the Atlantic coast.

"What the melting of the ice means is a real strong freshwater layer near the surface, so the water doesn't get mixed down or sink. It's too light," said Drinkwater, in Halifax this week for conference with the International Council for the Exploration of the Sea.

Drinkwater said the likelihood of this particular scenario is viewed as more remote than others that predict warming in the region.

But 400 scientists from the 20 member countries of the world's largest marine science and advisory group have gathered this week to discuss such theories and exchange ideas.

"It would have a bigger impact in Europe," Drinkwater said of the cooling theory. "It would affect the northeastern part of the Atlantic a bit more, but there would be ramifications for this area as well.

"It's really not clear at this stage exactly what will happen."

Daniel Duplisea, a scientist from Quebec who's also attending the conference, said the colder water flowing southward from the melted Arctic ice could result in a cooler climate on the East Coast.

"It's not even throughout the globe, what will happen with global warming," said Duplisea, who works with the federal Fisheries Department.

"In some areas, there will be less rain. In some areas, there will be more rain. In some areas, there will be ice melting and getting colder, and other areas it will be just warmer."

An influx of colder water farther south could upset ecosystems, resulting in smaller fish and causing species that prefer warmer water to move.

"Cold water means slower growth," he said.

This would be disastrous for coastal communities dependant upon the fisheries industry, such as in northern Quebec where they fish snow crab, he said.