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."

Climate Change Linked to Shrinking Birds

Photo: Scarlet Tanager.
Courtesy of TheMarvelousInNature from Flickr

Certain birds in North America are getting smaller, according to a paper published last year in the journal Oikos and covered in the October issue of The Scientist.

Researchers from the University of Zϋrich found that more than 100 bird species have shrunk in size over the past half of a century. This appears to be driven by climate change, since smaller body size and wing length provide an advantage in a warmer climate. What that advantage may be, is still unknown. However, it is well known that animals that live in warmer climates tend to be smaller. The changes observed could be the result of bird species adapting to a warming earth.

About half a million birds were weighed and measured in the study. On average, a species’ body mass shrunk by 1.3%. Some species, like the rose-breasted grosbeak, lost 4% over the 46-year study period. The most affected bird species were North American songbirds, but the pattern was also found in birds that spend the winter in the Caribbean and South America. The BBC’s coverage of the study includes more details and is worth checking out.

While it’s not easy to say whether these changes will have long-term effects on the bird populations studied, they have raised concerns about the consequences of a warming planet for birds.

“The fact that this selection seems to be favoring small birds and that the birds are getting smaller both suggests that the decrease in size is an adaptive response . . . But the problem is to what extent can you keep adapting in that way? If it keeps getting warmer, and you keep having to select for small size, then eventually you are going to see the consequences of that,” said Ary Hoffmann, commenting on the paper in The Scientist.

Welcome Peter Kent, Minister of the Environment

Nature Canada congratulates Peter Kent on his appointment as Canada's new Minister of the Environment. We welcome Mr. Kent to a portfolio that offers many opportunities for success in 2011.

The first opportunity will be to build on Jim Prentice's legacy and maintain the momentum towards completing Canada's systems of terrestrial and marine parks and protected areas. Mr. Kent will be able to draw on his experience as Minister of State for Foreign Affairs (Americas) to follow through on Canada's commitment to tri-lateral cooperation with the United States and Mexico on continental wilderness conservation. Examples of immediate do-able steps include working with the Dehcho and Tlicho Dene to formally establish the Edehzhie National Wildlife Area in the Northwest Territories, and working with the Oikigtani Inuit Association to negotiate boundaries for Lancaster Sound National Marine Conservation Area.

Secondly, the Minister will need to work with the Minister of Fisheries and Oceans to improve and accelerate the federal government's performance in implementing protection for Canada's ever-more-numerous species at risk. To date Canada has recognized over 600 species as being at risk of extinction, but has approved an action plan for recovery for only one species. The Minister should act quickly to ensure that the Government of Canada finally adopts a much-delayed suite of policies guiding implementation of the act.

Thirdly, the new Minister will face the challenge of convincing his cabinet colleagues to end the federal government's inaction on climate change. This will require a tidal shift to policies that effectively reduce Canada's greenhouse gas emissions. Related policies are also needed to rein in the many environmental impacts of the tar sands, and avert the looming environmental disasters associated with unconventional oil and gas development.

Finally, in the context of the UN decade for biodiversity and the international year of the forest, we at Nature Canada hope to work with the Minister and both Environment Canada and Parks Canada on the development of an ambitious national conservation plan.

We look forward to meeting with Mr. Kent and helping Canada seize the nature conservation opportunities that we are so fortunate to have.