INDEPTH: CLIMATE CHANGE
The tip of the iceberg
CBC News Online | March 24, 2005
Life on Earth is about change and adaptation. Since the beginning of time, species have had to adjust to the natural world. There have been ice ages, warm periods, and many major climactic events in the planet's history.
Species must adapt or die out. Knowing what's coming can sometimes give us an advantage.
Projected regional shifts of plants and animals
(Courtesy: ACIA)
Most of the scientific predictions about what will happen in the future are just that – predictions, but ones based on scientific evidence and research. Most begin with that careful word "if," indicating that "if" the humans continue to produce carbon dioxide at such-and-such a pace, then a certain result will follow.
What will happen if the global climate does go up 1.4 to 5.8 degrees C by 2100?
It's hard to imagine why an adjustment of just a few degrees will make much of a difference, since most of us live in climates that can vary more than that from day to day. But many scientists like to point out that at the end of the last Ice Age, temperatures were only a few degrees cooler than they are today.
That's because the temperature predictions are global averages, and don't really help in predicting what will happen in a particular region. Climatologists generally predict greater warming in more northerly climes, and greater warming during the winter months than during the summer.
Globally, water shortages could become much more common. Low-lying areas and islands would be threatened by rising sea levels. Many climatologists predict more extreme weather events including storms, droughts and floods. Changes in growing seasons and moisture levels will disrupt agriculture, and could lead to more famines.
Medical researchers say it's possible the world will see an increase in tropical diseases, if insect habitats spread with the warmer weather.
In Canada, we can likely expect more heat-related deaths, more precipitation in certain locations, longer growing seasons, evaporating lakes, and rising sea levels. As explained in this site, the Arctic region is likely to experience these things first, and people there have already begun to note the changes.
According to Environment Canada, B.C. and the Yukon are likely to see increased summer droughts and spring floods. Sea levels will rise up to 30 cm on the northern B.C. coast, and as much as 50 cm in the northern Yukon.
Climate change could also affect Canada's claims of sovereignty in the Far North. Longer warm spells, and melting could lead to more exploration for diamonds, minerals and oil. They could also mean the viability of the Northwest Passage, a possible trade route by sea that links the Atlantic and Pacific oceans.
Climate models suggest more droughts in the Prairies. Southern Canadian growing seasons may also be longer, but heat could lead to drier soil.
Ontario, particularly the southern half of the province, is likely to see warmer summers and winters, and longer growing seasons. The area is also likely to see an increase in pollution trapped in the air. The Great Lakes are likely to lose volume to evaporation.
Quebec would see similar changes, and an increase in precipitation in northern regions. The growing season would be longer, and agriculture could extend further north than it does today.
Environment Canada reports that the Atlantic provinces may not experience the warming trends expected in other parts of the country. The region has actually cooled in the last 50 years. But the coast will be strongly affected by rising sea levels, and the resulting effects on fish habitat.
In all regions, effects on wildlife and vegetation are difficult to predict. Some plants and animals adapt better than others.
Many climate and environmental researchers are starting to suggest that we will soon reach a "point of no return," meaning that we will have set the global climate on a course that is likely impossible to alter. There is no clear consensus on when that point will be reached, or, as some suggest, if we've already passed it.
Carbon dioxide from human activities could remain in the atmosphere for hundreds of years, so it's possible that today's drive to the store in a gas-guzzler could have an effect on children 200 years from now.
Not everyone believes we are nearing this point, or even that this point exists. The U.S. has so far refused to ratify Kyoto or other agreements that call for restrictions on carbon emissions. President George W. Bush's chief environment adviser, James Connaughton, put it this way to BBC Radio: "We are now trying to find a portfolio in which three words are important: technology, technology, technology."
In other words, the U.S. is looking to inventions and innovation to avoid drastic climate change and its effects. China has also stayed out of Kyoto, but made pledges on avoiding pollution, and using an alternative to carbon energy – nuclear power.
While it's hard to predict what future innovations may bring, many environmentalists charge that it will be too little, too late. The science is not definitive on this, but many climatologists say that reducing greenhouse gas emissions is crucial in slowing the change that has already begun.
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