How fast do trees have to move to avoid climate change?

Thanks to record rates of anthropogenic (i.e., manmade) climate change, ecosystems in some areas of the world are likely to have to move several yards a day to “keep up” with the change. Setting aside how difficult it is for trees to move several yards a day, though, a new paper points out that it’s much more complicated than simply moving.

The paper is included in this month’s special issue of Science, which examines “Natural Systems in Changing Climates.” One of the conclusions the authors reach is that “it is highly likely that [climate change] will intensify in the coming decades, unfolding at a rate that is [much faster] than the changes to which terrestrial ecosystems have been exposed during the past 65 million years.”

These results aren’t surprising to folks who have been tracking the science, but the authors present their findings in a way that really highlights the unprecedented velocity of manmade climate change. For example:

• Even with big cuts in greenhouse gas emissions, the climate is likely to change about 10 times faster than what’s been seen in the past 65 million years.
• If we continue with business as usual, climate could change as much as 100 times faster than anything terrestrial ecosystems have experienced in 65 million years.

Unfortunately, it’s not just the rate of climate change that will affect ecosystems in coming decades. Different species move at different rates. Microclimates and soil types differ quite a bit across relatively short distances. Mountains only go so high and continents don’t go on forever. Human land use change creates physical barriers, and air and water pollution are additional stresses. Add it all up, and the challenges and consequences for the ecosystems we know and love are daunting.

Certainly this sort of study – indeed all of the articles in this special issue of Science – can be depressing. But this paper, which was co-authored by my thesis advisor, who is the most determined clear-eyed optimist I’ve ever met, closes by noting that “the ultimate velocity of climate change is not yet determined… the greatest sources of uncertainty—and greatest opportunities for modifying the trajectory of change—lie in the human dimension. As a result, the rate and magnitude of climate change ultimately experienced by terrestrial ecosystems will be mostly determined [by] human decisions, innovations, and economic developments.”

We can do something about this, and at EDF, we are. See how we’re using rigorous science to help identify the most effective remedies.