A researcher and environmental activist said Yukon MP Ryan Leef refuses to acknowledge scientific realities when it comes to climate change.

Leef is attracting national attention over his belief that polar bears are not affected by global warming.

He made the comments in a reply to a constituent who is concerned about the future of the bears.

Leef said current estimates put the number of polar bears in the wild at 20,000 to 25,000. He said that means the population has quadrupled over the last 40 years.

The member of Parliament also said pessimistic studies about the bears have significant errors. He quoted one review which said the research should be considered "unscientific and inconsequential to decision makers." 

Steven Amstrup is the chief scientist for a conservation group called "Polar Bears International".

He said Leef's claim that polar bears are thriving is questionable.

But Amstrup added it's what happens in the future that's important, not what's happening now.

"Just as we don't have any evidence that the population, the world population, has really increased that much, we do have evidence that it can only go down in the future unless we change our ways."

Amstrup says Leef is relying on information put out by a group of people who deny the effects of climate change.