MAUNA LOA OBSERVATORY, Hawaii - The readings at this 2-mile-high station
show an upward curve as the world counts down to climate talks: Global
warming gases have built up to record levels in the atmosphere, from
emissions that match scientists' worst-case scenarios.
Carbon dioxide concentrations this fall are hovering at around 385 parts
per million, on their way to a near-certain record high above 390 in the
first half of next year, at the annual peak.
"For the past million years we've never seen 390. You have to wonder what
that's going to do," said physicist John Barnes, the observatory
director.
One leading atmospheric scientist, Stephen Schneider, sees "coin-flip
odds for serious outcomes for our planet."
Far from this mid-Pacific government observatory, negotiators from 192
nations gather in wintry Copenhagen, Denmark, next month to try to agree
on steps to head off the worst of the climate disruptions researchers say
will result if concentrations hit around 450 parts per million - in 30
years at the current rate. Some say the world has already passed a danger
point, at 350 ppm, and must roll back.
Today's emissions curve is tracking the worst case among seven emissions
scenarios set out in 2001 by the U.N.'s Intergovernmental Panel on
Climate Change (IPCC), British climatologists reported in September.
The U.N. expert group projects that such a path would raise global
temperatures between 2.4 and 6.4 degrees Celsius (4.3 and 11.5 degrees F)
by century's end. That would come on top of a global temperature increase
of about 0.6 degrees Celsius (1 degree Fahrenheit) in the past century, a
warming trend the authoritative IPCC says is mainly due to the buildup of
carbon dioxide and other greenhouse gases.
Such warming will shift climate patterns, cause more extreme weather
events, spread drought and floods to new areas, kill off plant and animal
species, and cause seas to rise from heat expansion and the melting of
land ice, the IPCC says.
"Changing several degrees may not seem like much, but we're just changing
things too fast," Barnes said. "So the consequences could well be
drastic."
The IPCC has urged industrialized countries to reduce global emissions by
25 to 40 percent below 1990 levels by 2020. As of 2007, they stood only 4
percent below 1990 levels, and the rest of the world continued pouring
out more and more heat-trapping gases, chiefly from the burning of coal,
gasoline and other fossil fuels.
Through this decade global emissions have grown by 23 percent. In 2008,
almost three-quarters of the increase came from China, researchers
reported last week. Other big contributors among developing countries
were India, Saudi Arabia, Brazil, South Africa, South Korea, Indonesia,
Iran and Mexico.
Experts see no sign of a slowdown.
It would "probably be at 390 (ppm) next year at Mauna Loa," said Fred T.
Mackenzie, a professor emeritus of oceanography at the University of
Hawaii at Manoa. That would represent almost a 40-percent increase in
carbon-dioxide density in the atmosphere since before the industrial age
and extensive use of fossil fuels.
Schneider, a Stanford University climatologist, said the world faces a
huge risk.
"I think meters of sea-level rise are virtually inevitable, unless we can
stop this. But I'm not such an optimist," he told journalists on a
fellowship program with the Honolulu-based East-West Center. "The main
message is we're in risk management. We do not know the science well
enough to know exactly what the temperature is at when a tipping point
will occur."
This U.S. government observatory, 11,141 feet (3,396 meters) up Mauna
Loa's northern flank, also measures methane and other significant
greenhouse gases. It was here on Hawaii's Big Island that climatologist
Charles David Keeling pioneered the measurement of carbon dioxide in the
atmosphere, installing his experimental manometer on the gently sloping
volcano in 1958.
He chose the site, already a U.S. Weather Service station, because the
trade winds blowing over it had some of the cleanest air on the planet.
Barnes said the CO2 measurements here, thousands of miles from major
industry, were the first to show that manmade carbon dioxide emissions
were accumulating throughout the global atmosphere.
The upward trend, averaging 1.9 parts per million per year in the past
decade, undergoes seasonal fluctuations. In summer, during the growing
season, plants absorb carbon dioxide from the atmosphere. But in winter,
the concentration of C02 rises as vegetation and other biomass decompose.
The observatory is part of the National Oceanic and Atmospheric
Administration's worldwide network for measuring greenhouse gases. It
coordinates measurements with other U.S.-run research stations in Alaska,
California, American Samoa and the South Pole. Japan and Australia also
run such networks.
The Mauna Loa researchers extend their measurements through their "flask
network" - containers sent to dozens of places around the world each week
or carried on commercial ships so people can fill them with air and send
them back to be measured for C02 and other gases.
Barnes, watching the carbon dioxide "ppm" curve track ever upward on
Mauna Loa, while some other greenhouse gases decline, noted that
long-lived CO2 is "more and more the bigger player."
"It is going into the ocean, and there's some plant uptake, but a whole
lot of it just goes into the air and it's going to stay there for
thousands of years," he said.
___
On the Net:
NOAA Mauna Loa Observatory: http://www.mlo.noaa.gov/
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