Here's a map from NASA that shows the amount of vegetative growth in the western hemisphere of the Arctic over the past 30 years. (The eastern hemisphere is even more impressive.)
It's mostly tundra and tiaga.
These images accompany a new paper in Nature Climate Change, that says latitudinal shifts in vegetation in the Arctic -- essentially, how fast the greening is moving north -- is 4-7° in 30 years. If I figured correctly, that's 445-778 km in 30 years, or about 50 meters a day, or about 2 meters an hour.
The paper says climate models predict the shift will be 20° more by the end of the century. That's about 1400 miles.
Denver will move to Mexico City. Saskatchewan will move to Houston. Fairbanks, Alaska will move to Portland, Oregon, and Portland will move somewhere equivalent to Miami's latitude. Unless someone can find a way to alter the molecular properties of carbon dioxide. I hope someone, somewhere, is working on that.