Put me down for some beach front property on Great Slave Lake
By the end of this century, fires will consume twice as much forest annually in Canada, a fifth of the currently snowy Arctic will be greened by tundra and Great Lakes water levels will have plunged still lower, international scientists are going to warn this week in an authoritative climate change report.
Economic damage from severe weather, such as hurricanes, is almost certain to continue rising in North America and city-dwellers face heightened health risks, the scientists conclude.
Yet Canada and the U.S. are ill-prepared to adapt to such almost-certain impacts from climate change, leaving their citizens vulnerable.
This grim regional picture is contained in the second report this year from the Intergovernmental Panel on Climate Change, to be published Friday.
The report summarizes the probable effects on people and the environment arising from the increase of 2 to 3 degrees C in average temperatures by 2050 forecast in the panel's first climate science study released in February.
The scientists conclude that the temperature-spurred shift of plants and animals northward and to higher altitudes "is likely to rearrange the map of North American ecosystems."
They also caution that climate change will hit hardest at specific groups in Canada and the U.S., like the urban poor and elderly, aboriginals and resource-dependent communities, such as lumber towns.
A collation of the top peer-reviewed scientific research over the past five years, the IPCC reports are produced by a United Nations network of 2,000 scientists as authors and reviewers.
The Star obtained a near-final draft of the IPCC Technical Summary, an 80-page document more detailed than the short political summary being edited in Brussels this week by representatives from 120 governments. Both documents are to be made public Friday.
Nearly six pages of the technical summary are devoted to climate change impact and vulnerability in North America and the polar regions. For most of the projected effects, the scientists rate the confidence level as "high" or "very high," meaning an 80 or 90 per cent chance of being correct.
Water in North America is going to come under particularly severe pressure because of climate change, the IPCC summary concludes.
For the Great Lakes and major river systems, "lower water levels are likely to exacerbate issues of water quality, navigation, hydro-power generation, water diversions and bi-national co-operation."
In addition, warmer temperatures affecting snowfall and rain over the Rockies by mid-century will probably reduce the summer flow in rivers and increase the risk of winter flooding.
Also a recurring theme is higher health and safety risk in North American cities because of climate change.
"Severe heat waves, characterized by stagnant, warm air masses and consecutive nights with high minimum temperatures, are likely to intensify in magnitude and duration over portions of the U.S. and Canada, where they already occur," the scientists say.
By 2050, deaths linked to smog could increase by almost 5 per cent because of higher ozone levels in cities already blighted by smog.
The summary does not identify individual cities.
The continent's ecosystems will be rearranged in both good and bad ways.
Forests may initially benefit from warming through faster tree growth but hotter summers in the second half of this century could lead to fires consuming between 74 and 118 per cent more forest than now.
Longer growing seasons should boost net agricultural production for a few decades but this will be accompanied by more insect plagues and more wildfires.
In the North, the scientists forecast that tundra will invade between 15 and 25 per cent of the current "Arctic desert," the region characterized by permanently frozen ground and minimal precipitation.
Other Arctic predictions include:
# Permafrost area could shrink by as much as a third by mid-century and the ground will thaw to a depth 50 per cent greater than usual during summer in northernmost locations.
# The summer spread of polar sea ice, already shrinking, should get still smaller by 22 to 33 per cent by the end of the century, opening navigation through the Arctic Ocean.
# Climate change at the poles will trigger global impacts, including a possible weakening of the ocean "conveyor belt" which brings warm water north from the tropics.
The detailed science underlying the IPCC conclusions won't be available until later this year when the full study will be published. It is expected to run between 300 and 400 pages.
