Man’s rapid impact outstrips measured nature
The headline glowing on the computer screen late this week signaled
alarm: "Climate risk to million species."
That’s the way the BBC News chose to sum up the conclusions of
scientists who looked at global warming in six regions of the world and
saw a doomsday future.
The report, "Extinction Risk from Climate Change," is part of a
United Nations-funded effort.
Changing rainfall patterns, growing desertification in Africa and
Asia, extreme flooding in Europe, tropical disturbances that roil oceans
– there is ample armchair evidence of climate changes.
Why does this have particular interest for those of us living here in
the Keys?
Look outside your window. You may have noticed we are surrounded by
water. Any warming that affects the oceans affects us.
Right off our coast, the Gulf Stream runs at breakneck speed, a giant
river of water that enriches the marine environment and feeds the
fertile fisheries of the North Atlantic.
Its warm waters even change the weather in the British Isles, which –
bereft of the Gulf Stream’s heat – would experience the frigid winters
of northern Europe.
Matthew Hart, author of "The Greenland Pump," writes:
"The Gulf Stream moves along the surface at 65 million cubic meters
per second, a flow equivalent to 100 times the water disgorged by the
Amazon river as it drains the greatest watershed on earth."
At the Grand Banks, this flow divides into two streams, he notes,
with the North Atlantic current flowing past the British Isles,
"delivering as it has for 10,000 years, a trillion kilowatts of heat
into the air."
That heated water hits the cold waters of the North Atlantic deep,
triggering a powerful exchange that pumps denser, colder water back
southward, recharging the oceans and renewing life on this planet.
Scientists now know the journey of those deep, cold underwater rivers
circling the globe resurface 1,000 years later in the North Pacific.
Just imagine, waters that flowed off the coast of Greenland at the time
of the Norman Conquest will be recharging the waters off Alaska some 60
years from now in 2066.
So when you read about scientific findings that have found global
temperatures increasing the past 100 years, be aware that nature
measures time in increments far beyond our ability to comprehend.
We quote here from Bill McKibben, author of "The End of Nature" and a
scholar-in-residence at Middlebury College:
"So far humanity has raised the planet’s temperature by about one
degree Fahrenheit, with most of that increase happening after 1970."
And that "one degree turns out to be a lot," he writes, noting that
"the frozen portions of the planet’s surface – glaciers – are everywhere
in rapid retreat.... The snows of Kilimanjaro are set to become the
rocks of Kilimanjaro by 2015."
So we see headlines about species at risk and wonder at what point
the species we threaten is us? |
