Greenhouse Gases Including Methane are Soaring
Greenhouse gases soar; scientists see little chance of
arresting global warming this century
Associated Press
21 November 2011
WASHINGTON — Heat-trapping greenhouse gases in the atmosphere are
building up so high, so fast, that some scientists now think the
world can no longer limit global warming to the level world
leaders have agreed upon as safe.
New figures from the U.N. weather agency Monday showed that the
three biggest greenhouse gases not only reached record levels last
year but were increasing at an ever-faster rate, despite efforts
by many countries to reduce emissions.
As world leaders meet next week in South Africa to tackle the
issue of climate change, several scientists said their projections
show it is unlikely the world can hold warming to the target set
by leaders just two years ago in Copenhagen.
“The growth rate is increasing every decade,” said Jim Butler,
director of the U.S. National Oceanic and Atmospheric
Administration’s Global Monitoring Division. “That’s kind of
scary.”
Scientists can’t say exactly what levels of greenhouse gases
are safe, but some fear a continued rise in global temperatures
will lead to irreversible melting of some of the world’s ice
sheets and a several-foot rise in sea levels over the centuries —
the so-called tipping point.
The findings from the U.N. World Meteorological Organization are
consistent with other grim reports issued recently. Earlier this
month, figures from the U.S. Department of Energy showed that
global carbon dioxide emissions in 2010 jumped by the highest
one-year amount ever.
The WMO found that total carbon dioxide levels in 2010 hit 389
parts per million, up from 280 parts per million in 1750, before
the start of the Industrial Revolution. Levels increased 1.5 ppm
per year in the 1990s and 2.0 per year in the first decade of this
century, and are now rising at a rate of 2.3 per year. The top two
other greenhouse gases — methane and nitrous oxide — are also
soaring.
The U.N. agency cited fossil fuel-burning, loss of forests that
absorb CO2, and use of fertilizer as the main culprits.
Since 1990 — a year that international climate negotiators have
set as a benchmark for emissions — the total heat-trapping force
from all the major greenhouse gases has increased by 29 percent,
according to NOAA.
The accelerating rise is happening despite the 1997 Kyoto
agreement to cut emissions. Europe, Russia and Japan have about
reached their targets under the treaty. But China, the U.S. and
India are all increasing emissions. The treaty didn’t require
emission cuts from China and India because they are developing
nations. The U.S. pulled out of the treaty in 2001, the Senate
having never ratified it.
While scientists can’t agree on what level of warming of the
climate is considered dangerous, environmental activists have
seized upon 350 parts per million as a target for carbon dioxide
levels. The world pushed past that mark more than 20 years ago.
Governments have focused more on projected temperature increases
rather than carbon levels. Since the mid-1990s, European
governments have set a goal of limiting warming to slightly more
than 2 degrees Fahrenheit (1.2 degrees Celsius) above current
levels by the end of this century. The goal was part of a
nonbinding agreement reached in Copenhagen in 2009 that was signed
by the U.S. and other countries.
Temperatures have already risen about 1.4 degrees Fahrenheit (0.8
degrees Celsius) since pre-industrial times.
Massachusetts Institute of Technology professors Ron Prinn, Henry
Jacoby and John Sterman said MIT’s calculations show the world is
unlikely to meet that two-degree goal now.
“There’s very, very little chance,” Prinn said. “One has to be
pessimistic about making that absolute threshold.” He added:
“Maybe we’ve waited too long to do anything serious if two degrees
is the danger level.”
Andrew Weaver at the University of Victoria, Granger Morgan of
Carnegie Mellon University and Gregg Marland of Appalachian State
University agreed with the MIT analysis that holding warming to
two degrees now seems unlikely.
“There’s no way to stop it. There’s so much inertia in the
system,” Morgan said. “We’ve committed to quite a bit of warming.”
Prinn said new studies predict that if temperatures increase by
more than two degrees, the Greenland ice sheets will start an
irreversible melting. And that will add to sea level rise
significantly.
“Over the next several centuries, Greenland slowly melts away,”
Weaver said.