Using data from 1982 to 2011, scientist Ranga Myneni of Boston University’s Department of Earth and Environment and colleagues studied vegetation rates at different latitudes, and the relationship between changes in surface temperature and vegetation growth 45 degrees north latitude to the Arctic Ocean.

And their findings, published in a study in the journal Nature Climate Change March 10, are alarming: Vegetation growth on the planet’s northern latitudes are resembling those in the south, thanks to the greenhouse effect. Northern latitudes are becoming increasingly covered with vegetation and it’s shifting the northern growing seasons.

In a press release from NASA, which also worked on the studied with an international cohort, co-author Compton Tucker of NASA’s Goddard Space Flight Center in Greenbelt, Md, says “It’s like Winnipeg, Manitoba, moving to Minneapolis-Saint Paul in only 30 years.”

Why is this a problem? Here’s Myeni’s take:

“Higher northern latitudes are getting warmer, Arctic sea ice and the duration of snow cover are diminishing, the growing season is getting longer and plants are growing more. In the north’s Arctic and boreal areas, the characteristics of the seasons are changing, leading to great disruptions for plants and related ecosystems.”

More from NASA:

The Arctic’s greenness is visible on the ground as an increasing abundance of tall shrubs and trees in locations all over the circumpolar Arctic. Greening in the adjacent boreal areas is more pronounced in Eurasia than in North America.

An amplified greenhouse effect is driving the changes, according to Myneni. Increased concentrations of heat-trapping gasses, such as water vapor, carbon dioxide and methane, cause Earth’s surface, ocean and lower atmosphere to warm. Warming reduces the extent of polar sea ice and snow cover, and, in turn, the darker ocean and land surfaces absorb more solar energy, thus further heating the air above them.