UN report confirms climate change is happening now

national post
The United Nations' scientific brain trust is poised to say that climate change, once a theoretical future scare story, is real, urgent and warming our air and water right now.

The update from the International Panel on Climate Change, expected Friday, will say it's practically certain the recent instances of unusually warm weather around the world are not natural glitches, but changes caused by human pollution.

Since the panel's last update (in 2001), science journals have been bursting with new measurements and examples of real warming in many places.

The global temperature has warmed up by an average of 0.6 to 0.7 degrees, says Matthew Bramley, director for climate change of the Pembina Institute, a Canadian climate group.

That's measured from pre-industrial times, but most of the increase has happened in the past few decades, he says.

If the increase reaches two degrees, he warns, that's when major and disruptive changes in weather patterns will likely occur.

''When you say one degree or two degrees (of warmer average temperatures) - it doesn't mean much to many people,'' he says. ''It's important to understand that five degrees (Celsius) was enough to make the difference between our climate today and Ottawa having kilometres-thickness of ice'' during the last Ice Age.

The IPCC's scientists are meeting in Paris this week to negotiate final wording of their new assessment of the ''basic science'' behind Earth's climate. In April, they'll announce what specific effects they foresee.

James Bruce, a veteran climate scientist from Ottawa who has worked in a variety of IPCC positions, said a review of the scientific findings in recent years points to several areas where the update is likely to focus.

The biggest change: The scientists who used mathematical models of what might happen a few years ago are now staring at actual measurements showing global warming that's well underway.

The University of East Anglia in England, a specialized climate studies centre, says the 12 warmest years on record have been in the past 13 years.

It also forecasts that 2007 will be a record-setter, 0.54 degrees above the long-term (1961-1990) average of 14.0 degrees worldwide. The hottest year so far was 1998.

''They've got far more evidence of trends in climactic factors and responses (of air and water) that point to the increasing strength of the warming than they ever did before,'' . Bruce said.

Among the findings:

* The oceans are warming with surprising speed.

The warming so far is just a fraction of a degree, but over the whole Earth this translates into a large amount of stored heat.

* The ''mid-latitudes'' - areas between the Arctic and the tropics, like southern Canada, Europe and the United States - are seeing increased incidents of violent weather, especially heavy rainstorms.

* The Gulf Stream is expected to weaken ''in the next little while.'' ''There is some evidence that it's already weakening a little,'' Bruce said.

For now, the Gulf Stream is what keeps Britain warmer than Labrador. The two are about the same distance north, but a cold Arctic current runs past Labrador while Britain gets warm water.

* There's a shift in where the greatest emissions are coming from. And the big source now lies in making electricity.

* Much of the warming has come near the Poles, raising the prospect of melting ice, which could sharply raise sea levels around the world and flood coastlines.