The Great Southern Exodus
“Imagine your lawn crawling north away from your house at a speed of about five and a half feet per year.”
It’s a powerful image Dr. Lawrence Smith uses to describe the impact of climate change in his recent book, The World in 2050: Four Forces Shaping Civilization's Northern Future, which has garnered him media attention.
After a bit of searching, I found numerous credible sources
citing scientific papers that back up his startling prediction. It falls in line with research findings that have been years in the making. I might add that to understand the full impact of Smith’s analogy, you’d also have to imagine that your south-facing backyard is shrinking, drying up, and losing lustre.
But we’re not just talking about your lawn and backyard vegetable patch. Smith paints a picture of a very real and extensively documented phenomenon that will have wide-ranging effects. As global temperatures rise, plants and animals will be pushed north and up in to higher altitudes.
Animals and plants are sensitive to changes in temperature, with several studies showing that some have adapted to regional warming by shifting their range to the north. Global-scale models predict a continuous northerly shift in both plant and animal distributions.
But keep in mind that even if species have the flexibility to adapt and keep up with a changing climate, physical barriers such as mountains and human settlements could stand in the way. Other factors like food availability and soil types could also prevent a range shift.
Animals and plants that are already under considerable stress are least likely to make the move north, a point that is highlighted in an assessment
by the European Environmental Agency.
In a recent interview
with Bob MacDonald, host of CBC Radio’s Quirks and Quarks, Dr. Smith updated his original analogy to something a bit more dramatic in scale.
“It's five and a half feet per day," Dr. Smith told host Bob McDonald. "And this number refers not to the spread of agriculture, but to the mass migration of biological life that is already happening on our planet and has been for several decades. On average the world's plants and animals have been moving northward to higher latitude at a rate of about six kilometres per decade."