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Our World Transcript — 25 February 2006


This transcript is provided as a service; there may be some variation between it and the program as broadcast.

MUSIC: Our World theme

Straight ahead on "Our World" ... The thawing of the Arctic permafrost ... El Niño's impact on African farmers ... and new moons found orbiting around Pluto.

WEAVER: "This is going to give us two new Kuiper Belt objects to look at in addition to Pluto and Charon. With the New Horizons mission, we get basically a half-price sale now, four for the price of two."

Those stories, a listener question about how water drains, our Website of the Week and more. I'm Art Chimes. Welcome to VOA's science and technology magazine, "Our World."

Scientists warned this week that melting permafrost in the Arctic could have significant impacts far beyond Siberia and other areas where a permanently frozen layer of soil sits under the surface.

Arctic temperatures are increasing about twice as fast as the rest of the planet. Rising atmospheric temperatures are already noticably melting some of the permafrost layer, says David Lawrence of the National Center for Atmospheric Research, or NCAR.

LAWRENCE: "In virtually all locations there's a positive [warmer] trend in the permafrost temperatures at varying depths. You take this in conjunction with some more anectodal evidence where scientists or indigenous people or local people are going out in the field and seeing that there's pretty large changes: what once used to be a frozen area is turning into a boggy marsh in some situations. So there's pretty widespread evidence changes are occuring to permafrost conditions sort of as we speak."

At a Capitol Hill seminar, Lawrence explained how permafrost may begin several meters below ground and extend to a depth of a kilometer or more.

Even though permafrost is not on the surface, its presence can be seen. For example, northern Siberia is covered with lakes, the water sealed in from the bottom by the icy permafrost. And now, many of those lakes are disappearing.

Laurence Smith of the University of California – Los Angeles displayed satellite images from 30 years ago alongside recent pictures of the same area in western Siberia that clearly show the vanishing lakes. As permafrost melts, he said, the water has to go somewhere, and it ends up in the Arctic Ocean.

SMITH: "River runoff, as David has discussed, is on the rise. And furthermore, the model predictions of river runoff suggest that these increases are going to go even higher. Why is this important? Why are these river runoff increases important? Well that fresh water freezes more readily than salt water. So it leads to increased formation of sea ice, which then gets exported out through the Fram Straight into the North Atlantic region."

As that sea ice moves into the Atlantic, it threatens to disrupt water currents there, possibly resulting in regional climate changes, including dramatically cooler temperatures in Europe.

NCAR computer simulations project that over the next century as much as 80 percent of the permafrost will melt.

Permafrost holds an enormous amount of carbon locked up in ice. When that melts the carbon could be released into the atmosphere either as carbon dioxide or methane, depending on local conditions. Both are greenhouse gases, with methane the more powerful of the two. So even as Europe gets colder, overall global average temperatures could rise.

Another part of the scenario looks at changes in vegetation. As an area becomes warmer, vegetation increases. Grasses are replaced by shrubs and bushes, which are replaced by trees. That makes the surface darker, which absorbs heat, adding to the cycle of warming.

These factors and many others are part of sophisticated computer programs called climate models, designed to predict what will happen in the decades to come. Most of these models now predict a warmer planet over the coming decades. David Lawrence says civilization will likely learn to live in the new climate.

LAWRENCE: "You know, as humans we can adapt. That's probably true. We can adapt. But the big question is whether ecosystems can adapt at the same pace. And the idea is that, most likely not in the same way that humans can adapt. And that's obviously going to be a concern for us in the future."

David Lawrence of the National Center for Atmospheric Research. He and UCLA's Laurence Smith presented their research on permafrost this week at a seminar sponsored by the American Meteorological Society.

With most reputable climate scientists in agreement that the warming trend will increase dramatically in the coming century, scientists are trying to determine how life will change on a warmer Earth. Most of the studies thus far have focused on physical changes, like the environment, agriculture, and rising sea levels. But as VOA's Rosanne Skirble reports, a new study published in the British journal, The Lancet, explores the possible implications of a warmer planet on human health.

McMICHAEL: "We know of course that severe heat waves kill people. We know that extremes of cold kill people.

SKIRBLE: Anthony McMichael is a co-author of a new study on the links between climate change and human health.

McMICHAEL: We know that a lot of infectious diseases are sensitive to temperature, to humidity, to rainfall, particularly the ones that are spread by mosquitoes -- like malaria, dengue fever and yellow fever. We also know that as the world warms, the weather patterns are likely to become much more variable around the world and therefore populations are going to be exposed to an increased frequency and increased intensity of extreme weather events..."

SKIRBLE: … which could lead, says McMichael, to more cyclones, storms, floods and droughts, all of which have consequences for human health.

McMichael heads the National Center for Epidemiology and Population at the Australian National University at Canberra. He points out that the impact of extended heat waves has already been observed in numerous places. He cites examples in Alaska, Canada, and Australia, and the unusually high death rate in Western Europe brought on by a heat wave in 2003.

McMICHAEL: "It was associated with an extraordinarily excess of deaths during and immediately after the heat wave, a total of about 35,000 excess deaths, mostly in France, Italy and Spain, but throughout western Europe, and including England."

SKIRBLE: According to historical records, that deadly heat wave was a once-in-four-centuries event. But forecasters say this scenario could be repeating itself every 4 years by 2050, if current trends continue.

Climate scientists see a warming trend behind the reduction in Arctic sea ice, and the retreat of mountain and land glaciers. McMichael notes a worrisome increase in correlation with the rising temperatures - the emergence of infectious disease.

McMICHAEL: "That includes malaria in Africa, tick-born encephalitis in Sweden, patterns of cholera in Bangladesh, which come and go with changing temperatures of coastal waters, and recently a very interesting report of increased annual frequency of food poisoning off the north coast of Alaska from bacterially-contaminated oyster beds known to be very temperature dependent."

SKIRBLE: Scientists from various disciplines have begun to collaborate on climate issues to predict, for example, the path of malaria in a warmer world.

McMICHAEL: "To obtain from them their best models of how patterns of temperature and rainfall will change by gridded location around the world and then connect that up with our own biological models that express what we know about how temperature, rainfall, humidity affect the biology of the mosquito and the biology of the malaria parasite. And from that, [we would] work out approximately the effects on future patterns of malaria."

SKIRBLE: Anthony McMichael believes that increased public education, community support and advance policy planning, especially among the poorest and most vulnerable communities, will be essential to mitigating the health effects of climate change before it is too late. I'm Rosanne Skirble.

One difficulty faced by scientists and policymakers looking at long-term climate change is that there is considerable variation from year to year. A couple of warm years might be part of a long-term trend, or it could be the result of normal short-term variations. One powerful factor in annual changes is known as El Niño.

El Niño is marked by warmer water temperatures in the tropical Pacific, along with changes in trade winds and rainfall. There's also a cold counterpart called La Niña, or a cold El Niño. A similar pattern in the Atlantic is called the North Atlantic oscillation. Using four decades of weather data and food production records, scientists in Norway and the United States found a strong association between those weather patterns halfway around the globe and food production in Africa.

Hans Herren of the Millennium Institute in Arlington, Virginia, is one of the co-authors. He notes that the effect observed varied in different parts of Africa, and with different crops.

HERREN: "West Africa is less affected. Exactly why, I don't think that this is clear. It's just sort of that we can see a more marked tendency in eastern and southern Africa, southern Africa even more so, I think, than other areas."

For example, in southern Africa, maize production was down about 12 percent in strong El Niño years.

Because El Niño can now be predicted months or even a year in advance, Herren says this link between climate and food production provides a powerful planning tool.

HERREN: "We know now that certain occurrences of the El Niño, for example, gives an indication depending on whether it's a warm or a cold El Niño, if some areas of the planet - here we're talking about Africa in particular - will be rather on the wet side or on the dry side. And we can now predict these occurrences with fairly good accuracy and also enough time lag for the farmers to take appropriate measures."

And not only the farmers. Governments, too, can act, for example by stockpiling crops ahead of an anticipated bad year and by encouraging diversification, which offers some protection against being wiped out when one particular crop fails.

The study by Hans Herren and his colleagues appears in the Proceedings of the National Academy of Sciences.


Thanks to the Internet, we can get authoritative medical information in the middle of the night, or maybe pay bills or take a university course online. It's also revolutionized many hobbies. Genealogy is a popular and addictive pastime for many who want to explore their family histories, and there are thousands of websites that have really made a difference for people who want to find out where they came from. Since February is Black History Month here in the United States, let's take a look at one site that is both a tool and a community for African-American genealogists. Our Website of the Week is Afrigeneas.com.

OLIVER-VELEZ: "We point them in the right direction. We don't do your research for you, but we can hook you up with people who can set you on the right path."

Denise Oliver-Velez is the host of the "getting started" forum on Afrigeneas. That forum and many others include thousands of messages from people looking to find or share information. One user asks about a particular family, trying to find if other people are researching the same ancestor. Another asks if racial classifications listed in census forms are reliable. There are forums based on geographic area, on slave research, on cemeteries and even the newest tool of genealogy, DNA research.

Plowing through old census documents, family histories, land records and, for African-Americans, slave records to find your ancestors can be rewarding, but it can also be challenging and even intimidating.

OLIVER-VELEZ: "You never know what you're going to uncover when you start going into the past. And you're able to share with others both the joys of finding family and also some of the heartaches that you uncover when you start uncovering you roots."

Just in the past decade or so, new resources have emerged online to help genealogists conduct research from the comfort of their own computer. There are still many records that have to be viewed in person, but Oliver-Velez says information is available online.

OLIVER-VELEZ: "We not only have resources on the site, we have quite a number of databases available for those who are looking for, for example, a particular surname or who are looking in a particular geographical region for their ancestors."

Denise Oliver-Velez of African-American genealogy website Afrigeneas.com. You can also find the link on our site, voanews.com/ourworld.


MUSIC: "Let's Celebrate" by Robin Hogarth

You're listening to VOA's science and technology magazine, Our World. I'm Art Chimes in Washington.

Researchers at the University of Pittsburgh have developed a prototype avian flu vaccine using parts of the deadly H5N1 virus. They say that in tests, the new vaccine completely protected all mice and chickens against the disease.

The vaccine combines a live common-cold virus with genetic material from the flu virus. The vaccine is grown in cells, unlike the way conventional flu vaccine is made, using dead virus cultured in fresh poultry eggs.

Current flu vaccines protect against only one strain of the disease. But Dr. Andrea Gambotto of the University of Pittsburgh says the new vaccine may protect against a broader range of flu virus variations. That could be a big help to public health authorities.

GAMBOTTO: "If the virus changes a little bit while you are stockpiling the vaccine, what happens is that you need to start from scratch and maybe you have finished all the eggs to make the vaccine. So, you may end [up] to have nothing and not having even the capability to produce a new one."

Gambotto expects to begin human clinical trials of the vaccine within six months.

GAMBOTTO: "I'm optimistic of course. I expect that this vaccine will be effective in humans. The only thing that I don't know is how much vaccine I need to give to the people to generate immunity which relates to protection. "

He added that the genetic engineering approach offers great promise against other emerging diseases.

Andrea Gambotto and his colleagues published their findings in the journal "Virology."

Some 170 people have caught avian flu from infected poultry, and about half of them have died. Public health experts fear that a mutation of the virus may make it possible to catch the bug from an infected person, not just an infected bird. That, they say, could set the stage for an influenza pandemic.

U.S. astronomers using the Hubble Space Telescope have discovered two new moons orbiting Pluto, the icy ninth planet that orbits about six billion kilometers from the sun. The discovery comes just a month after the launch of New Horizons, which is scheduled to be the first space probe to do a close-up fly-by of Pluto. VOA's Jessica Berman has details on the new discovery.

BERMAN: The New Horizons space probe was launched in January to explore the icy planet of Pluto, and its moon Charon, 6.5 billion kilometers from Earth.

It will take almost 10 years for the probe to reach Pluto, our solar system's most distant planet.

But scientists have found two more moons for the spacecraft to inspect during its brief nine-hour fly-by.

Using the Hubble Space Telescope, astronomers detected the two small, faint moons orbiting Pluto in the Kuiper Belt, a region of the galaxy beyond Neptune that is the cradle of asteroids, comets, and icy bodies, including Pluto.

Hal Weaver of Johns Hopkins University Applied Physics Laboratory in Maryland is a scientist on the New Horizon's mission.

WEAVER: "This is going to give us two new Kuiper Belt objects to look at in addition to Pluto and Charon. With the New Horizons mission, we get basically a half-price sale now, four for the price of two."

The new moons are called P1 and P2. Weaver says they are four- to six-thousand times fainter than Pluto, and two- to three-times as far away from Pluto as Charon.

For that reason, no one could see P1 and P2 with the world's best ground-based telescopes. But that did not stop Alan Stern of the Southwest Research Institute in Colorado, who began hunting for other moons around Pluto 15 years ago.

Pluto and Charon orbit around each other in what astronomers call a binary system. Experts say the twin orbits suggest that Pluto was created by a massive impact and Charon is a remnant of that explosion.

Stern reasoned, if that were the case...

STERN: "... Pluto would have small satellites accompanying its large one, Charon. And when we got the right tool, we put the nail through the coffin in eight-minutes flat with the Hubble Space Telescope."

Stern, the principal investigator for the New Horizons mission, says P1 and P2 track Charon's orbit perfectly, which supports the idea that Pluto was created by a massive impact.

Two papers by Weaver, Stern and their colleagues describing the discovery of Pluto's two moons appear in the February 23 issue of Nature. Jessica Berman, VOA News, Washington.

Finally today, we are overdue in answering a listener question. We invite you to write in with science questions, and I admit we don't do a very good job of finding time to answer them. Too much science news, and too little time each week on "Our World" is the problem. Anyway, this week our question comes from Han Qian Bao. He writes to us from Yan Tai, in Shan Dong province, China, about how water flows down a drain – clockwise in the southern hemisphere, counterclockwise in the north -- or so he's heard. He wants to know why that is, and what happens to in water drains on the equator.

Well, I remember hearing the same thing, too. To get to the bottom of things I talked with Professor Jim St. John, at Georgia Tech, the Georgia Institute of Technology in Atlanta. I told him I thought this had to do with something called the "coriolis" effect

ST. JOHN: "That is correct. The coriolis effect is what's being talked about here. The problem arises in that in order to get a good coriolis effect, you have to have scales of motion on the orders of hundreds to thousands of kilometers and time periods on the order of hours to days."

As a result, the coriolois effect is too weak to have any meaningful effect on how water flows down a drain. Instead, says St. John, other factors take over.

ST. JOHN: "When you flush a toilet or have water go down a bathtub, the frictional forces on that water are much greater than the coriolis effect."

The coriolis effect, or force as it's also called, results from the rotation of the earth. Imagine a ship at the equator firing a cannon due north. From the ship, it would look like the cannon ball went straight ahead. But because the earth is rotating underneath, the cannon ball would seem to curve off to the right. Coriolis is strongest near the poles and decreases as it approaches the equator.

ST. JOHN: "Hurricanes, tropical cyclones, typhoons don't happen at the equator because the coriolis effect is zero there. So to answer the question, what would happen at the equator when you have water go down the drain? It all depends on the friction at the bottom of the bathtub."

So in summary, no coriolis effect at the equator, and elsewhere it's not strong enough to affect how water goes down a drain.

I hope that answers Mr. Han's question. We'll be sending him a VOA gift as our way of saying thanks for sending in his question. If you have a science question, we'll send you a gift if we answer your question on the air. Write us at ourworld@voanews.com, or listen for our postal address at the end of the show.


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That's our show for this week. We always like to hear from you. Email us at ourworld@voanews.com. Or use the postal address -

Our World
Voice of America
Washington, DC 20237 USA.

Our show was edited by Rob Sivak. Eva Nenicka is our technical director. And this is Art Chimes, inviting you to join us online at voanews.com/ourworld or on your radio next Saturday and Sunday as we check out the latest in science and technology...in Our World.

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