A report that argues global warming is a greater threat to world security
than terrorism and predicts a warming future where "disruption and conflict
will be endemic features of life," may sound like it came from a radical
environmental group - but it didn't. Unless you consider the Pentagon a
radical environmental group.
The report, submitted last fall, but only recently released to the media,
looked specifically at what would happen if the world's climate were to
abruptly shift, rather than change at a constant pace, as most people
naturally assume it would do.
Of course, this is the Pentagon talking about worst-case scenarios. And the
more skeptical among us could argue that the Pentagon probably has a
scenario for what would happen if Canada tried to invade the U.S. by
building a bridge made of Tim Horton's doughnuts across Lake Ontario.
Inventing scenarios is just what they do.
But it would be a mistake to simply dismiss the Pentagon climate report,
because it is based on real science. Abrupt climate change is both scary
and plausible - and we've known about it for some time. Our atmosphere and
our oceans are all part of one big heat-transfer system, and ocean currents
are a key driver of our climate. If we somehow change these currents, we
change the climate - and this can happen very quickly.
So how would we alter ocean currents? Well, the greatest and most
mysterious ocean current is called the thermohaline circulation, or the
Great Ocean Conveyor, which exchanges warm and cool water around the world.
It moves slowly, but the amount of water it carries is massive - the
equivalent of 100 Amazon Rivers. Part of this conveyor is the Gulf Stream,
which brings warm water from the equator up to Europe, where it releases
its heat, cools and sinks near the Arctic. The Gulf Stream helps moderate
Europe's climate. Without it, most of the continent would be much colder.
But as we add heat-trapping gases to the atmosphere and warm the planet, we
increase the amount of fresh water that melts from glaciers and Arctic ice.
This fresh water is less dense, so it doesn't sink, which slows down the
Gulf Stream. If it were to slow significantly or stop (which appears to
have happened in the past), Europe could very quickly plummet into a little
ice age. Much of North America would also become cooler, drier and windier.
As the Pentagon points out, this could wreak havoc on agricultural
production and the economy, leading to major social upheavals.
The Pentagon report may be a worst-case scenario, but it's about time the
U.S. government finally took an interest in climate science. In February,
dozens of prominent U.S. scientists, including 20 Nobel Laureates, signed a
statement of complaint against the Bush administration for misusing science
"by placing people who are professionally unqualified or who have clear
conflicts of interest in official posts and on scientific advisory
committees; by disbanding existing advisory committees; by censoring and
suppressing reports by the government's own scientists; and by simply not
seeking independent scientific advice."
We must hope that, with the Pentagon now actually examining climate science
seriously, the Bush administration will give it the attention it deserves
and join the rest of the world in working to reduce the heat-trapping gases
that cause global warming.
That's not to say Canada has its act together. Although we have adopted
Kyoto and committed to reducing our emissions, we haven't actually done
anything yet. Over the next few months, our prime minister will unveil his
strategy to meet the Kyoto Protocol and start addressing climate change. It
had better be good. By acting now, we can avoid the Pentagon's worst-case
scenario.
