Monday, March 05, 2007

James Hansen: Climate Deadline

To listen to/download the audio mp3, click the title above.

It's time to hear the awful truth: Nature's carbon clock is ticking. We have less than ten years to make a major turnaround, according to one of America's top scientists.

This is Alex Smith of Radio Ecoshock.

Despite being censored by the Bush administration, there is an important recent interview with James Hansen, the outspoken climate scientist at NASA. This one comes from independent radio journalist Maria Gilardin, who has produced an intriguing series of alternative specials at TUC Radio.

TUC stands for "Time of Useful Consciousness." It's a flying term, referring to the amount of time a pilot can react to save the plane, after the oxygen system fails, before passing out. I guess we are in that boat now, when it comes to human civilization, the climate, the oceans, and the ecosphere generally.

As Director of the NASA Institute for Space Studies in New York City, part of the Goddard Space Flight Center, James Hansen has testified about climate change to Congress and the Cabinet (including Vice President Cheney). This interview was captured on a San Francisco roof, following Hansen's lecture at the December 2006 meeting of the American Geophysical Union.

You can get more information from Maria's website at, and the full speech from our website at in the Climate section of our Audio on Demand menu. I'll just give you some critical highlights from the interview.

For example:

"We did not realize, until recently, that previous warm periods, that previous so-called inter-glacial periods, some of which were warmer than the present one, were not very much warmer. At most, one degree warmer than the present period.

On the other hand, there were times, if we go back three million years ago, when the Earth was about three degrees warmer, but it was a different planet! There was no sea ice in the Arctic. And sea levels were at least 15 meters higher, probably about 25 meters higher - that's 80 feet. I mean, that's a huge climate change. It's something that we really would have a very hard time dealing with, because we've set up all or our infrastructure with the coast lines where they are now.

And also, a warming that large would have a huge impact on many species. It would drive many high latitude and high altitude species to extinction. So, we really cannot afford - we really don't want to have a climate change of anything like that magnitude."

Or this:

"And if we want to preserve a planet resembling the one we inherited from our fathers, we're going to need to change the course of our emissions into the atmosphere. And in fact there are other reasons that it makes sense to do that.

I think we still have time to do that, but unless we begin to make changes this decade, it's going to be very difficult to preserve a planet similar to the one that we inherited."

We all need to grasp the concept of "thermal inertia" - the science of how some climate change is coming no matter what we do.

Maria Gilardin asks:

"In your talk, just now, you referred to half a degree Celsius that is still in the pipelines, regardless of what we do. I missed that date by which you expect to see that half a degree warming to occur."

Jim Hansen replies:

"Yes, because the ocean has large thermal inertia, it takes it a long time to respond to changes in the heating. And there's still about half a degree Celsius of global warming that's in the pipeline, just because of this slow response time of the ocean.

Some of that warming, more than half of it, should occur within a few decades, but part of it will take more than a century, just because the ocean is very deep, and it turns over very slowly."

Then there is the deep ocean, which churns very slowly, over hundreds of years.

"One of the interesting things is that, deeper ocean is now getting warmer, which is not surprising, because as we warm the surface, the rate of formation of deep water, which is formed at the high latitudes, is decreasing. And that causes the deep ocean to warm. Because normally it cools, by formation of deep water at high latitudes.

So it's a complicated ocean/atmosphere system, and the changes that we are seeing, I think do make sense. But there's variability from year to year, just because the climate system is a non-linear chaotic system, just like the weather. It's going to fluctuate warm and cold, and we have to look at the long term, in order to really understand what is going on."

Hansen has suggested an alternative, or supplemental method of preserving the Arctic from the worst of climate change: by controlling methane. For more on this, see my own special "Methane Primer" and "The Methane Fix" in the Ecoshock Features section of I discuss the American plan, now expanded to other countries, to control methane as a way to combat climate change.

Here, Maria Gilardin asks:

"You said in one of your papers, that carbon dioxide is not the only Greenhouse gas. And that there are other gases that contribute to global warming as well."


"Yes. It's very important to realize that it's not only carbon dioxide. There are other gases, methane being the second most important, and tropospheric ozone, which is a pollutant. And in addition, there are particles, like black soot.

And one of the things, which I think is very important, is that although it looks like the Arctic is now beginning to lose it's ice, and there's a prediction that we will lose all the ice in the Arctic by 2040 - but in fact some of the non-CO2 climate forcings are particularly effective in the Arctic. And we could reduce those, easier than we could change carbon dioxide.

There's going to be some increase in carbon dioxide, even if we try to use energy more efficiently. But we could reduce methane, which in turn, would reduce tropospheric ozone. And we could also reduce the black soot particles.

If we do that, then I think we can retain the sea ice in the Arctic."


"How do we go about reducing methane?"


"Methane has a number of sources. Landfills are one of them. You can design your landfills so you can capture the methane, and then use it, as natural gas, for heating purposes. In addition, there's methane lost in fossil fuel mining, in coal mines. And again, that can be captured, and used as a fuel. So we need to pay attention to the various sources of methane, and reduce those. That would go a long way toward saving the Arctic."

Next Maria moves to the dreaded feed-back mechanisms that can create runaway climate change. We find that positive feed back loops can kick in after just one degree Celsius of warming! This is a key point. And I love how sirens from the street below intrude for a few seconds, as Hansen describes a possible rapid unwinding of our climate echo of the future?

When Maria refers to the Hadley Centre in the UK, you should take some time to find her six part radio series on British scientific predictions of climate change. Important stuff. Check out her website, or search for Gilardin as a producer on the radio exchange site - the series is archived there.


"One of the issues that were dealt with at the Hadley Centre, in the UK: comprehensive descriptions of the feed-back mechanisms, and methane was one of them. The recent releases of Tundra-bound methane in Siberia, that's caused by global warming, have already been measured."


"You know, as we look at the history of the Earth, we realize more and more how important feed-back processes are. That's one of the reasons that I argue that we better keep warming less than about one degree, because we know that in the previous inter-glacial periods that were warmer by up to one degree, the feed-backs were there, but they were moderate.

On the other hand, if we have warming of two or three degrees, we're almost certainly going to melt most of the Tundra, and that's going to release methane. And we can then get very positive feed-backs, and we may get a system that's really out of our control."

Maria Gilardin:

"Do you want to say something about feed-back systems in the oceans?"


"Yeah, the ocean is another important source of feed-backs. Now, the ocean is taking up about 40 percent of the carbon dioxide that we put into the atmosphere. But, if the rate at which we put it into the atmosphere continues to increase, then one of the feed-backs is the ocean will become LESS capable of taking up CO2. And that will provide a positive feed-back, in effect, and we'll get still more warming. [Sirens]"


"And what about feed-back from the ice sheets, the Greenland and West Antarctic ice sheets?"


"The ice sheets on Greenland and Antarctica contain enough water to raise sea level many tens of meters. Greenland has about six or seven meters of sea level. West Antarctica has another 6 or 7 meters, and East Antarctica has about 16 meters.

The West Antarctic ice sheet and Greenland are particularly vulnerable. They are beginning to show signs of increased melt. If we have warming of more than about a degree, I think it's likely that we will lose both West Antarctica and Greenland.

The issue is: how long will it take? It had been thought that it may take millennia.

But the more and more data that we get, we find that ice sheets in the past have responded quite rapidly. There was Melt water Pulse 1A about 14,000 years ago, and sea level went up 20 meters in 400 years. Well that's one meter every 20 years. And that was with a forcing much weaker than the human-made forcing.

So is a real danger that we could set in motion disintegration of the Greenland and especially the West Antarctic ice sheet - and get changes quite rapidly, even this century."

Warming can develop quite rapidly, Hansen says:

"The data that we get from Greenland and Antarctic ice cores is remarkable. One of the things that it shows is that climate changes in the past, when we go toward a warming climate, it can happen very rapidly. Much more rapidly than as we go toward a colder climate. And the reason is positive feed-backs.

If you start to get warmer, and begin to get melting, then the ice becomes darker. Wet ice is much darker, and it absorbs more sunlight, and it melts much faster. And as the ice sheet begins to get smaller, then the surface lowers, and so it gets warmer. So there are multiple positive feed-backs, which can accelerate in a warming phase."


"You mentioned ten years a little while ago, not millennia, not a hundred years, but ten."


"Yes, because if we look at the Earth's history we realize that while one degree warming is perhaps something we can deal with, but more than that's beginning to become really a problem. And the problem is we already have additional warming in the pipeline. If we continue with business-as-usual, then carbon dioxide emissions by 2015 will be 35 percent larger than they are in the year 2000. And it will be impossible to get onto a scenario that keeps warming under one degree.

Like Ross Gelbspan, James Hansen also worries about Nature's deadline.


"Last year the 10 year deadline by which action is needed was set at the G8 meeting, and it was pretty much ignored. So, I've been deducting. We're now at nine."


"That's right. Because I argue that by 2015, that's when we're 35 percent higher if we continue with business as usual. So we've really got to get the attention of the public now. Because it takes time to make the changes in the infrastructure.

It's very unfortunate that this global warming story is cast as a doom and gloom story. Because it's not in fact a gloom and doom story. If we decide to deal with it, there are many benefits in cleaning up the atmosphere and reducing the emissions. And reducing our dependence on fossil fuels, because that's a source of a lot of problems.

And in fact, it is possible to have improved technologies that use much less energy. And to develop renewable energies. And this will produce high tech, high paid jobs. So the only people harmed are the people who are strongly trying to influence the discussion - some of the existing fossil fuel industry.

But for the people at large, it would make sense to begin to make the changes that are needed.

I tell young people that they had better start to act up. Because they are the ones that will suffer the most. Many of the changes will take time, but we're setting them in motion now. We're leaving a situation for our children and grandchildren which is not of their making, but they're going to suffer because of it. So I think they should start to act up and put some pressure on their elders, and on legislatures, and begin to get some action."

You have been listening to Dr. James Hansen, Director of the NASA Institute for Space Studies, interviewed in San Francisco by Maria Gilardin of TUC Radio. Maria has more climate interviews on offer at her site, She also has a recent program on Ralph Nader and the Green Party in America.

The text of this interview is available from the Ecoshock News blog at

I'm your host, Alex Smith for Radio Ecoshock. Thanks for listening. Sign up for our podcast to get our latest features, and check out my weekly radio show on CFRO FM in Vancouver Canada, live Fridays at 1 o'clock, on the Net at, by Star Choice Satellite channel 845, or later by download, at


Anonymous Anonymous said...

thought you might like to know of an expedition leaving London UK on March 2007 to study climate change

A unique dog-sledding expedition focusing on the early victims of climate change - leaving the UK for the arctic on March the 7th 2007.

"We shall be travelling on dogsleds through Arctic Finnmark, from the Barents Sea to the Atlantic, a journey of close to 1,500 kilometres in rugged conditions and temperatures ranging from minus 10 degrees C to minus 35 degrees"
The expedition focuses on the lives of an indigenous people of Finnmark, the Sámi. It’s a human story rather than a cold scientific story. It’s a drama that is easily relatable through interviews and observation - the effects of climate change will be made real and the implications more pressing by focusing on real lives.

4:52 AM  

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