In 1993, the United Nations refugee agency (UNHCR) identified four primary factors behind human displacement: political instability, economic tension, ethnic conflict, and environmental degradation, and estimated an annual displacement rate of about 47 million individuals.

These displacements involve internal refugees – those who leave home but remain in their country of origin, and external refugees, who ask agencies like the UNHCR to relocate them. Some of these people return, or are repatriated, once the crisis is past. Many more never again see the land of their birth.  

Unfortunately, humans aren’t the only species at risk of becoming refugees as the climate warms. Animals and plants are also changing their location in response to warming. For animals, the transition is far easier; they have legs and can walk or run. Thus, though they are never as adaptable as humans (sometimes needing very precise social living conditions, specific types of food plants, and critical habitat like rocks or forests to survive), many species of animals have so far managed to keep ahead of climate change, if only barely.

But not all. The American Pika, an adorable, small mouse-like mammal with round ears and a distinctive whistle, is one of the species likely to fail during this current epoch of anthropogenic (human-caused) climate change. This is because Pikas live in high, cool mountainous regions of the Western U.S. (think Glacier National Park and Yellowstone in the Rocky Mountains, or Yosemite National Park in the Sierra Nevada range).

For the Pika, there is literally no place to go but up, and there is no “up” left. They are already at the top of their range, and descending into lowlands to travel to higher elevations in other areas is equally risky to staying put. In fact, some Pika “villages” in the two mountain ranges framing the Great Basin area have already failed, according to Dr. Erik Beever, an ecologist with the United States Geological Survey (USGS).  

For plants, which have no feet, the transition in a warming climate is even more difficult. These native trees, shrubs, flowers and grasses are also moving north, and geographically upward, wherever possible, but where a human – or even a Pika – might make the journey in a single lifetime – plants have to rely on a species survival technique that involves dispersing their seeds into those more desirable areas until one of the seeds “takes.”

A perfect example of the difficulty is presented by the American sugar maple. Tapped since Colonial days for its sweet sap – the source of maple syrup – the sugar maple once ranged from the Atlantic Coast to the Mississippi Valley, and from Tennessee in the south to Minnesota in the north.

Now, with climate change making the New England states much warmer than formerly, the maple tree is slowly disappearing across the entire southern portion of its range. In fact, in 100 years (says Barry Rock, a professor at the University of New Hampshire), the sugar maple may disappear from every eastern U.S. locale except possibly northern Maine – the northernmost point along the Atlantic coast.

Humans are also lucky enough to have maps, like the one created by the European Commission, which direct them to the most likely future homesites. Animals don’t have that luxury, though they do have superb instincts that allow them to respond to a changing climate to the best of their abilities. Plants have nothing except the natural instinct to survive and propagate.

It’s not hard to guess which species will come off worst in the new Climate Change Migrations.

 (Image courtesy nnimalspot.net)