AnimalVoicesNews
Copy: BushWatcherNews
Source/Letters: Newsweek <Letters @ newsweek.com> (close spaces)
Link: <http://www.msnbc.msn.com/id/16946173/site/newsweek/?rf=nwnewsletter>
<http://www.msnbc.msn.com/id/16946173/site/newsweek/page/2/>
Forging a Consensus
The mammoth U. N. report on climate changethe work of 3,700 scientists the
world overis out. Their conclusion: We made this mess.
Web Exclusive
By William Underhill
Newsweek
Updated: 12:10 p.m. MT Feb 2, 2007
Feb. 2, 2007 - Global warming skeptics take note. The science behind climate
change looks ever stronger, and mankind is almost certainly to blame for
resetting the global thermostat. That¹s the key conclusion of the
Intergovernmental Panel on Climate Change (IPCC), which published the
summary of its latest report today with a warning that world average
temperatures could climb several degrees by the end of the century. And its
findings will be tough to challenge. The panel, backed by the United
Nations, draws on research from thousands of scientists from around the
world. The report summary (the full report is due out in May) pulled back on
some of the more alarming claimsparticularly on the rate of sea-level rise.
NEWSWEEK¹s William Underhill spoke to climate scientist James Murphy, one of
the report¹s authors, from the Hadley Centre for Climate Prediction and
Research in England.
NEWSWEEK: There were many authors of the report. How difficult was it to
reach agreement?
James Murphy: Consensus was hard won. A massive amount of research now goes
on. Between one IPCC report (the last was in 2001) and the next there must
be thousandsor even tens of thousandsof papers produced. So it is a
difficult job to sift all the evidence and delineate the key messages.
So what are the key messages that emerge?
The previous report emphasized that we could detect a warming up of the
earth¹s surface and attributed some part of that to man¹s activities. There
is now a whole range of new indicatorsatmospheric temperature changes,
temperature trends below the surface of the ocean, as well as retreating
snow and ice cover particularly in the northern hemisphereand they are all
pointing in the same general direction.
Does the evidence really leave no doubt that man is responsible for the
change?
It would be a problem statistically to attribute the entire warming trend to
man¹s activities, but we can make a strong statement that we are responsible
for a substantial part. Certainly we can¹t explain that basic trend without
invoking the response to greenhouse gases and aerosols.
Is it possible to link the spate of freakish events such as Hurricane
Katrina to global warming?
The area of tropical storms is still controversial, cyclones in particular.
But we do see evidence of increases in extreme eventswarm nights, hot days,
heavy precipitation.
And can we assume that a rise of one or two degrees above pre-industrial
levels is now inevitable?
We have already observed a rise of 0.74 degrees since the start of the 20th
century. What the models now show is that even if we were able to stabilize
greenhouse-gas concentrations in the atmosphere at present-day levels, we
would see a further rise of at least half a degree by the end of the
century.
But that¹s the very minimum. When you put in a realistic scenario of future
emissions [the rise] will be much larger. In fact, if we continue on the
emissions pathway projected for the next few decades, we can expect to see a
further warming at least as great as what we have seen since the Industrial
Revolutionand quite likely larger. Our best estimate is three degreesif we
don¹t take drastic steps.
To many people, that might not sound so much. What would be the practical
consequences?
Just a warming of one degree would have quite a significant impact. The
models suggest that the land will warm at a faster rate than the sea, so we
could see a greater percentage of land affected by drought. In most regions
of the world we would see more heavy storms, heatwaves, uncomfortably hot
days, a further retreat of sea ice and snow cover in the northern
hemisphere, as well as further rises in sea levels.
© 2007 Newsweek, Inc. |
© 2007 MSNBC.com
© 2007 Microsoft
~~~~~~~~~~~~~~~~~~~~~~~~~>
This is distibuted for nonprofit research and educational purposes only.
[Ref.http://www4.law.cornell.edu/uscode/17/107.html]
You are invited to read past articles and alerts, subscribe, or unsubscribe
or email with subject "subscribe" or "unsubscribe."
BushWatchersNews:
http://groups-beta.google.com/groups?q=bushwatchernews&start=0&scoring=d
AnimalVoicesAlerts:http://groups-beta.google.com/group/AnimalVoicesAlerts
AnimalVoicesNews: http://groups-beta.google.com/group/AnimalVoicesNews
