DIANE SAWYER (ABC NEWS)(OC): Good
evening. We begin with a new report and
a major alert about the speed of climate change on this planet. Hundreds of scientists from around the globe
saying today there is evidence that global warming is accelerating - sea levels rising, greenhouse gases mounting, glaciers
melting. And for the first time, a government-backed report links
the recent wild weather to manmade causes. So is
this a kind of tipping point? ABC's weather
editor Sam Champion begins by breaking it down for us.
SAM CHAMPION (ABC NEWS)(VO): The
extreme weather of 2011.
PEDESTRIAN (MALE) Oh, gosh that is a
monster tornado.
SAM CHAMPION (ABC NEWS)(VO): The worst drought in a decade, even the recent headline
of the hottest 12 months we've ever lived through,
all are a global concern. Areas of the
world are getting hotter and drier. Flood zones getting pummeled. Extreme weather becoming the rule not the
exception. And according to many
scientists, global warming is a cause.
HEIDI CULLEN (CLIMATOLOGIST CLIMATE
CENTRAL): What we know really well about global warming is it increases the
likelihood of more extreme events.
SAM CHAMPION (ABC NEWS)(VO): Today, hundreds of scientists from 48 countries
released their annual state of
the climate
report, which shows the trend toward a rapidly warming planet has been
accelerating. The study examined
headlines, like rising temperatures both on land and in our oceans, and
examined disappearing sea ice.
SAM CHAMPION (ABC NEWS)(VO): 2011
showed the second smallest area of ice on record. Also noting glaciers around the world continue to shrink. Greenland has one of the largest ice bodies in the
world. And pictures now show Greenland's
glaciers are melting 30 times faster than they were a decade ago.
SAM CHAMPION (ABC NEWS)(VO): Over the
last century, sea levels have risen about ten inches. But by 2050, scientists predict the level
will increase another foot.
SAM CHAMPION (ABC NEWS)(VO): If that holds true, parts of cities like
Miami and New Orleans will be under water.
For the first time in its history, this study says 2011 weather extremes are connected to manmade global warming.
SAM CHAMPION (ABC NEWS)(VO): This
study does not make prediction forces the future but it begs the question, have we reached
the tipping point? Scientists tell us
not yet.
HEIDI CULLEN (CLIMATOLOGIST CLIMATE
CENTRAL): There may not be tipping point this year or next year. But the odds just keep growing. And it's one of those problems where the
sooner you deal with it, the easier it is.
DIANE SAWYER (ABC NEWS)(OC): And I
want to turn to Sam Champion right now.
So Sam, how did they link this to manmade causes for the first time?
SAM CHAMPION (ABC NEWS)(OC): In
looking through the report, Diane, the one thing they won't do is say is that
that particular thunderstorm or that particular flood event was caused by
global warming. But what they do say is
that all of these greenhouse gases are
on the rise
and at the largest and highest levels that they've seen since they've been
keeping records - carbon dioxide, methane and nitrous oxide. They also say that
they were not able to detect natural rises in greenhouse gases.
DIANE SAWYER (ABC NEWS)(OC): So these
are manmade gases they're seeing and not natural gases.
SAM CHAMPION (ABC NEWS)(OC): For the
first time that's what the report says.
DIANE SAWYER (ABC NEWS)(OC): Now we
heard it's not yet the tipping point. So
still time to do something?
SAM CHAMPION (ABC NEWS)(OC): Well, in
my, if you want my opinion, Diane, what I would say is now is the time that we
start limiting manmade greenhouse gases if we're starting to see that that is
exactly what other studies are showing.
DIANE SAWYER (ABC NEWS)(OC): All
right, well this will start a lot of conversation, a big new report today,
thanks, Sam.