This story is part of a CBC News series entitled In Our Backyard, which looks at the effects climate change is having in Canada, from extreme weather events to how it’s reshaping our economy.

Flying over southern New Brunswick in a helicopter, it doesn’t take long to spot moose running through the snow in the forest beneath. What isn’t visible from the air are the thousands of ticks invading their bodies.

In nearby New Hampshire and Maine, over a three-year period, scientists…