Lonnie Thompson is a paleoclimatologist who studies ancient weather patterns, dating back hundreds of thousands of years.

Lonnie Thompson is a paleoclimatologist who studies ancient weather patterns, dating back hundreds of thousands of years. He has drilled ice cores in glaciers from the Himalayas to the Andes, and has become one of the world’s foremost authorities on the evidence of climate change. Thompson is a distinguished university professor in geological sciences at Ohio State University, and a research scientist at the Byrd Polar Research Center.  Here, he talks with reporter Martin Smith about the impact of accelerating ice loss across the Himalayas, which serve as a water tower for more than one third of the world’s population.

GLACIERS ARE OUR EARLY WARNING SYSTEMS

MARTIN SMITH: Let's begin talking about the Himalayas. Why should anyone care about glacier melt in the Himalayas?
LONNIE THOMPSON: First of all, what's happening to the glaciers there is just an indicator of what's happening to climate – the rising temperatures that are happening globally. They're our early warning system of that change.

But it's also the source of many major rivers that a lot of people depend on for water supplies, for everything from hydroelectric power production to irrigation to municipal water supplies. As those glaciers disappear, it's like having a bank account [that] you continuously are withdrawing money from. Eventually, you lose that resource. That is what's unfolding in that part of the world right now.

Give me a sense of the scale, of the amount of ice and the number of rivers that we're talking about?
We're talking about thousands of glaciers scattered throughout the Himalayas and across the Tibetan plateau, in the very highest mountains there. Those serve as source waters for everything, from the Yangtze River in China to the Indus River and the Ganges River, where you've got millions of people living downstream. What happens to those glaciers and what happens to the water supply at the source is extremely important.

Is climate change happening faster in the Himalayas than it is in other parts of the earth?
It's a very interesting question because if you look at the most recent IPCC [Intergovernmental Panel on Climate Change] report and the projections for warming in the next 100 years, the mean warming is three degrees Celsius. That's tremendous over 100 years.

But if you look at the distribution vertically, you see the warming concentrated in the tropics, in the low latitudes at the higher elevation sites. If you look at the elevations of the top of the Himalayas, there the projections are for five- to six-degree warming in the next 100 years. And this has to do with the positive feedback through water vapor in the tropics and the low latitudes. I think that these glaciers, and what's happening there are [an] early warning of changes taking place.

Look at the temperature records from Tibet. There are about 178 weather stations across Tibet. There have been studies to look at where the temperature [is] rising in Tibet. You find that the maximum rate of temperature rise is at the very highest elevation stations. That's on the order of about 0.3 degrees Celsius per decade. That's much higher than the temperature rise for the rest of the planet.

How will warming affect the people who live on either side of the Himalayan range?
It'll depend on where [they]'re located, where the city is located. I can give you an example of a city at the base of this Nanu Nami mountain that we drilled in September and October 2006.

There's a city there, Barang, on the northern border of India that has been there for over 1,500 years. It was on the old north-south Silk Road between India, across Tibet. Its water supply, 85 percent of its water in the dry season, is coming from the glaciers. So you see a city that's been there for over 1,500 years, and you wonder, how will it manage with the diminishing of the glaciers in this region as we go forward in the future. Can that city survive?

How many people live there?
I would guess somewhere around 150,000 people. When you go down from the mountain range, you know,it's kind of wet on top of the mountain, when you're at the very highest places. But as you go down to the base of the mountain, there are sand dunes. You go down in valleys, and they're really dry parts of the world, except for the water that's coming from the glaciers and from the higher elevation sites. So these people will be immediately at risk. If you go on down the valley into India and look at all the cities downstream, these people are also at risk, as you have diminishing water supplies.

A DIMINISHING BANK ACCOUNT

So why would there be diminishing water supplies? The glaciers are melting, that would increase the water supply.
In the short term, this is correct. In fact, I think in a lot of places where we work around the world – we've worked in about 15 different countries – there's actually more water in the rivers in the last 100 years because they've been tapping this archive that has built up over thousands of years.

This bank account.
That bank account is being diminished, and diminished very rapidly in many, many of these sites. That's a problem that's going to become worse as you go forward in time. As the glaciers diminish, you have less and less water available during the dry season and during the droughts. In some ways, think of glaciers as water towers.

They kind of store the water from the wet season, and they disperse it during the dry season and dry times. They do that for free. These cities have built up around this water supply that's actually been maintained because of this natural balance that exists in the system. But these glaciers will pass through a threshold where they no longer can feed the rivers. That's when you'll start seeing the real impacts on people who live in those areas.

How much of the population downstream derives its water from glacier melt as opposed to other sources, run-off, snow pack, whatever?
I don't think we know those percentages very well in that part of the world. We've got a much better understanding of the importance of snow pack in the Sierra Nevada here in the U.S. than we do in this remote part of the world.

Why is that?
Lack of measurements. Some of these glaciers we go to, you know, we're the first people who’ve been there. We don't have this well-developed history of climate variability in those areas.

What you're saying is we've got this very important third polar ice cap, if you will, 5,000 glaciers, but very few weather stations, very few study centers?
Exactly. You have to question the wisdom of not monitoring those sites better because there are so many people who depend on that water supply and the climate in that region for their existence. With the ice cores, we're trying to look at the annual history going back thousands of years, as it's preserved at the very highest places in the Himalayas.

If you take a big, well-known river like the Ganges, for instance, do we know how much of its water is coming from the glaciers and, therefore, how much of a difference glacier melting will have on the huge population that depends on it?
I don't think we have good numbers on that. There are a lot of things that we need to know about the glaciers that exist there. Number one: How thick are they? I mean, we have data that show the retreat and the fact that the retreat's accelerating, but that's based on the area.

But we know that the Gangotri Glacier, the main glacier that feeds the Ganges, is retreating, I don't know, 75 feet a year?
Yes, that's right. If you look at those numbers, you can see that the rate of retreat is accelerating, and that's the disturbing part about the studies of these low-latitude glaciers. It's not a constant rate – it's accelerating.

WOULDN’T THE ICE BE MELTING ANYWAY?

What about this idea that glaciers are a vestige of the ice age, that their disappearance is inevitable, global warming or not?
It's for sure that glaciers on this planet have come and gone due to natural variations of climate. But on top of that, we've got the CO2 emissions, the greenhouse gases, the human impact. We also have the impacts of the emissions, everything from sulfate to soot coming from all the industry in the world. We have changes due to deforestation, land-use changes. All those things impact the climate of the earth.

Our best understanding of the last 100 years is that if we didn't have the anthropogenic, the human factors, temperatures would not be going up today.

The greenhouse gases, the human activity, do we know that is linked to the glaciers in the Himalayas melting?
The fact that the glaciers are melting on a global basis links the two. It's the balance of evidence when you look at every place, from the Andes through the Himalayas, to the glaciers in Africa, to those in the Rocky Mountains. They're all giving the same story.

But back to the original question. There are those who say that is due to the end of the last ice age. How does one respond to that?
I would say that yes, there has been natural variability in the climate system. One of the reasons we drill ice cores is to understand that natural variability. That's certainly an important factor in the climate history on this planet. But what is really disturbing is that when you look at the temperature rise that has taken place, particularly in the last 20 years, every year we're setting new records.

CHINA’S RESPONSE

What has the Chinese response to this been?
The Chinese are very concerned about these changes, in part because of water resources and the fact that so many people live downstream on the Yangtze River. There are so many different ways the Chinese are impacting their environment. You know, deforestation, they have a lot of problems with desertification, more and more dust storms coming out. We even get that dust here in the US and southeast Alaska.

I think they have to be extremely concerned about energy. You know, they would like, as all countries would like, to have economies like the western world. They're working toward having that. But if they had a standard of living like we have by, say, 2030, they would need 99 million barrels of oil a day to support that. The world currently produces 84 million barrels a day, and there's no indication that's going to increase. In fact, there's a lot of discussion about that going down.

So how are you going to provide energy for 1.3 billion people in a world that is running out of fossil fuels? I think they, in many ways, see this investment into alternative energies as maybe the only way forward. There's a real potential in countries like China that they may do a technological leap because they have not yet made all that investment in infrastructure – pipelines and refineries and shipping. They may actually latch onto new technologies much faster than maybe we will [because] we have all of these vested interests in place.

The notion is that they're not going to do anything because they don't care – they just want growth; they just want development.
No, I think there are many well-educated people in China in positions of power. We deal with a democracy where everything is discussed and everybody's got to get on the same page before anything happens. In a government like they have in China, they can actually build the Three Gorges Dam; they can put in canals that move water from the Yangtze to the Yellow River. It will happen because of the type of government they have. There are thinking people in power who can and, in many cases, do make the right choices.

I guess I'll just throw it out. I don't know what to make of all the noise that I hear out there. Some people are saying, "Look, it's been actually getting cooler in the Himalayas, that most of these rivers downstream don't depend on glaciers."

Well, I hear these rumors also. But I can tell you that every place I've been – and we've been working in Tibet for over 28 years – the ice is melting,and the rate of that ice loss is accelerating.

I hear stories in Pakistan, for example, that glaciers are actually advancing in today's world. I've not seen any of those. I've seen lots of glaciers across Tibet. I think one of the issues is going out and doing the hard work of getting real data. That's job number one.

WHAT THE SCIENCE SAYS

Listening to you I get the sense that there's some very disturbing trends going on in the Himalayas, and we don't have enough study going on to fully understand what the consequences are going to be.
Well, I'm particularly disturbed about those changes that we have seen in the last 10 years in the Himalayas. We just came back from drilling this Lanu Nami site. One of the first things we do when we come back from any of these sites is look for radioactive layers from thermonuclear bomb tests that man has done. [The tests] leave radioactive layers throughout the Tibetan plateau. [The layers are] throughout the Andes and South America. This latest site that we drilled, the first thing we looked for is the 1962 Soviet test.

That was a big hydrogen bomb explosion.
And it's global. We use it as a marker because as soon as you know where that marker is, you can calculate the accumulation rate, the precipitation [rate] since 1962 for all these places.

Gives you a reference point.
It gives you a reference point. It's not on Lanunami. We just found out…

That means?
That means that there has been no net accumulation since 1962. Then we go into the earlier bomb tests, which [include] the Ivy Test, a U.S. test done at sea level which produced chlorine-36. We see it around the world. We just [got] the results two nights ago from the [Laboratory for Solid State Physics, the] ETH facility in Switzerland – not there.
That means there has not been a net accumulation at 20,000 feet on the Lanu Nami Glacier since at least 1950. That means that glacier is a remnant of a previous climate, and this issue may be much more serious than we thought.

How much would we have seen since 1950 or 1962? How much would you have expected had there not been this climate warming?
That's a good question because we don't know. We don't know what the accumulation rate has been in this area. We have to have time horizons, known time horizons to calibrate the core.

And the Chinese government is employing some of the best glaciologists in the world, as I understand it.
Yes, they are. They're really investing in trying to understand the climate in places like Tibet and the Himalayas because of the importance to resources.

THE MISCONCEPTION ABOUT THE CHINESE

How many trips to China have you taken?
I've made 28 trips to China. I went to China in 1984 when relations were just normalized between the U.S. and China. And I have watched a lot of development taking place. But I also watched the investment that the Chinese government is making into their young people, into science.

Their lab for doing ice-core research is three times better than mine equipment-wise. And they're building new campuses in Lhasa and in Beijing. I see a real investment in trying to understand the climate system, the environmental system in China. I think we have a misconception that the Chinese people, the government in particular, are not concerned about these environmental issues. They are.

So when you hear that being said by politicians in Washington, you think they're just wrong?
I think it's wrong. It's become an excuse for not doing what we can do, the things we should be doing in this country. You know, if we don't get moving on this soon, we're going to lose the glaciers. In fact, I'm absolutely sure many of these glaciers are already doomed by what we've done.

This is a humanity problem. It has nothing to do with politics. It has nothing to do with what your bottom line's going to be this quarter or next year. It has to do with our ability to survive on the planet.

We've got to start looking at solutions. You know, how do we replace what nature has done for free as far a regulating water discharge? Capturing it during the wet seasons and letting it out during the dry seasons. [We] live in a world where we occupy just about every possible piece of land that you can grow crops on. If you displace people, those people have to go somewhere. The geopolitical implications of those changes are huge.