Last week a large chunk of the Wilkins ice shelf (Antarctica) collapsed, producing a massive iceberg. These types of collapses open fissures that fill with water, leading to further collapses in what can become runaway cycles.

As a result of this runaway, the rest of this large ice shelf, which may be as much as 1,500 years old, will soon become victim to rising Antarctic air and sea temperatures.

By now, we hope most readers understand the overwhelming consensus of the scientific community is that global warming is a real phenomenon, and that production of greenhouse gases by human activities are a major contributing cause. In a 2007 synthesis report for policy-makers, the Intergovernmental Panel on Climate Change (IPCC) stated “warming of the climate system is unequivocal …”

The consensus of these scientists is warming temperatures have already begun to have real impacts. For example, we are seeing rises in global sea levels, both from melting of sea ice and from thermal expansion.

In Canada, the most marked effects have been in high latitudes, with increased glacial melt and instability of permafrost. Closer to home, we have seen earlier arrival of spring (although this is a really bad time to convince you of that), and a northward increase in the range of some plants and animals. We have also seen milder winters that fail to kill off insect pests, resulting in increased outbreaks in spring and summer.

In predictions for future climate change, we used to hear there would be winners and losers. The predictions of the IPCC report make it clear there are only big losers and minor losers. Low-lying tropical islands are the most obvious big losers, but projected water stress in Africa, Latin America and the Mediterranean region add them to this list.

By comparison, we are minor losers. Atlantic Canada will likely experience more frequent, intense storms as tropical storms track further north. In the west, we can expect drier climate and longer periods of drought, and northern Canada will become warmer and wetter. In central Canada, we can expect warmer climate, but with more extreme hot days in the summer, contributing to smog problems in and near cities. Near the lakes, warmer water temperatures and longer ice-free periods might result in more of the dreaded lake effect snow. We might benefit from increased agricultural production in Ontario, but the reality is most of our soil is marginal at best.

Change isn’t just coming, it’s already here. The proverbial canary in the coal mine has been replaced by the penguin on the ice shelf. Climate changes here at home have been more gradual, more subtle than Manhattan-sized chunks of ice dropping into the sea, but that makes them no less real.