Climate change is here -- and worse than we thought 

By James E. Hansen, Published: August 3

Washington Post

http://www.washingtonpost.com/opinions/climate-change-is-here--and-worse-than-we-thought/2012/08/03/6ae604c2-dd90-11e1-8e43-4a3c4375504a_story.html

When I testified before the Senate in the hot summer of
1988 , I warned of the kind of future that climate
change would bring to us and our planet. I painted a
grim picture of the consequences of steadily increasing
temperatures, driven by mankind's use of fossil fuels.

But I have a confession to make: I was too optimistic.

My projections about increasing global temperature have
been proved true. But I failed to fully explore how
quickly that average rise would drive an increase in
extreme weather.

In a new analysis of the past six decades of global
temperatures, which will be published Monday, my
colleagues and I have revealed a stunning increase in
the frequency of extremely hot summers, with deeply
troubling ramifications for not only our future but
also for our present.

This is not a climate model or a prediction but actual
observations of weather events and temperatures that
have happened. Our analysis shows that it is no longer
enough to say that global warming will increase the
likelihood of extreme weather and to repeat the caveat
that no individual weather event can be directly linked
to climate change. To the contrary, our analysis shows
that, for the extreme hot weather of the recent past,
there is virtually no explanation other than climate
change.

The deadly European heat wave of 2003, the fiery
Russian heat wave of 2010 and catastrophic droughts in
Texas and Oklahoma last year can each be attributed to
climate change. And once the data are gathered in a few
weeks' time, it's likely that the same will be true for
the extremely hot summer the United States is suffering
through right now.

These weather events are not simply an example of what
climate change could bring. They are caused by climate
change. The odds that natural variability created these
extremes are minuscule, vanishingly small. To count on
those odds would be like quitting your job and playing
the lottery every morning to pay the bills.

Twenty-four years ago, I introduced the concept of
"climate dice" to help distinguish the long-term trend
of climate change from the natural variability of
day-to-day weather. Some summers are hot, some cool.
Some winters brutal, some mild. That's natural
variability.

But as the climate warms, natural variability is
altered, too. In a normal climate without global
warming, two sides of the die would represent
cooler-than-normal weather, two sides would be normal
weather, and two sides would be warmer-than-normal
weather. Rolling the die again and again, or season
after season, you would get an equal variation of
weather over time.

But loading the die with a warming climate changes the
odds. You end up with only one side cooler than normal,
one side average, and four sides warmer than normal.
Even with climate change, you will occasionally see
cooler-than-normal summers or a typically cold winter.
Don't let that fool you.

Our new peer-reviewed study, published by the National
Academy of Sciences, makes clear that while average
global temperature has been steadily rising due to a
warming climate (up about 1.5 degrees Fahrenheit in the
past century), the extremes are actually becoming much
more frequent and more intense worldwide.

When we plotted the world's changing temperatures on a
bell curve, the extremes of unusually cool and, even
more, the extremes of unusually hot are being altered
so they are becoming both more common and more severe.

The change is so dramatic that one face of the die must
now represent extreme weather to illustrate the greater
frequency of extremely hot weather events.

Such events used to be exceedingly rare. Extremely hot
temperatures covered about 0.1 percent to 0.2 percent
of the globe in the base period of our study, from 1951
to 1980. In the last three decades, while the average
temperature has slowly risen, the extremes have soared
and now cover about 10percent of the globe.

This is the world we have changed, and now we have to
live in it -- the world that caused the 2003 heat wave
in Europe that killed more than 50,000 people and the
2011 drought in Texas that caused more than $5 billion
in damage. Such events, our data show, will become even
more frequent and more severe.

There is still time to act and avoid a worsening
climate, but we are wasting precious time. We can solve
the challenge of climate change with a gradually rising
fee on carbon collected from fossil-fuel companies,
with 100percent of the money rebated to all legal
residents on a per capita basis. This would stimulate
innovations and create a robust clean-energy economy
with millions of new jobs. It is a simple, honest and
effective solution.

The future is now. And it is hot.

(c) The Washington Post Company

___________________________________________

Portside aims to provide material of interest to people
on the left that will help them to interpret the world
and to change it.

Submit via email: [log in to unmask]

Submit via the Web: http://portside.org/submittous3

Frequently asked questions: http://portside.org/faq

Sub/Unsub: http://portside.org/subscribe-and-unsubscribe

Search Portside archives: http://portside.org/archive

Contribute to Portside: https://portside.org/donate