ERIC HOLTHAUS - The Point of No Return: Climate Change Nightmares Are Already Here
Historians may look to 2015 as the year when shit really
started hitting the fan. Some snapshots: In just the past few months,
record-setting heat waves in Pakistan and India each killed more than 1,000
people. In Washington state's Olympic National Park, the rainforest caught fire
for the first time in living memory. London reached 98 degrees Fahrenheit
during the hottest July day ever recorded in the U.K.; The Guardian briefly
had to pause its live blog of the heat wave because its computer servers
overheated.
In California, suffering from its worst drought in a millennium, a
50-acre brush fire swelled seventyfold in a matter of hours, jumping across the
I-15 freeway during rush-hour traffic. Then, a few days later, the region was
pounded by intense, virtually unheard-of summer rains. Puerto Rico is under its
strictest water rationing in history as a monster El Niño forms in the tropical
Pacific Ocean, shifting weather patterns worldwide.
On July 20th, James Hansen, the former NASA climatologist who brought climate change to the public's attention in the summer of 1988, issued a bombshell: He and a team of climate scientists had identified a newly important feedback mechanism off the coast of Antarctica that suggests mean sea levels could rise 10 times faster than previously predicted: 10 feet by 2065. The authors included this chilling warning: If emissions aren't cut, "We conclude that multi-meter sea-level rise would become practically unavoidable. Social disruption and economic consequences of such large sea-level rise could be devastating. It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization."
Eric Rignot, a climate scientist at NASA and the University
of California-Irvine and a co-author on Hansen's study, said their new research
doesn't necessarily change the worst-case scenario on sea-level rise, it just
makes it much more pressing to think about and discuss, especially among world
leaders. In particular, says Rignot, the new research shows a two-degree
Celsius rise in global temperature — the previously agreed upon
"safe" level of climate change — "would be a catastrophe
for sea-level rise."
Hansen's new study also shows how complicated and
unpredictable climate change can be. Even as global ocean temperatures rise to
their highest levels in recorded history, some parts of the ocean, near where
ice is melting exceptionally fast, are actually cooling, slowing ocean
circulation currents and sending weather patterns into a frenzy.
Sure
enough, a persistently cold patch of ocean is starting to show up just south of
Greenland, exactly where previous experimental predictions of a sudden surge of
freshwater from melting ice expected it to be. Michael Mann, another prominent
climate scientist, recently said of the unexpectedly sudden Atlantic slowdown,
"This is yet another example of where observations suggest that climate
model predictions may be too conservative when it comes to the pace at which
certain aspects of climate change are proceeding."
Since storm systems and jet streams in the United States and
Europe partially draw their energy from the difference in ocean temperatures,
the implication of one patch of ocean cooling while the rest of the ocean warms
is profound. Storms will get stronger, and sea-level rise will accelerate.
Scientists like Hansen only expect extreme weather to get worse in the years to
come, though Mann said it was still "unclear" whether recent severe
winters on the East Coast are connected to the phenomenon.
And yet, these aren't even the most disturbing changes
happening to the Earth's biosphere that climate scientists are discovering this
year. For that, you have to look not at the rising sea levels but to what
is actually happening within the oceans themselves..
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