Climate change discussions often focus on carbon dioxide, but another major culprit gets unleashed every time a truck drives on diesel fuel.

Black carbon, a principle component of soot, contributes more to climate change than previously thought, new research shows. In fact, black carbon could have as much as 60 percent of the current global warming effect of carbon dioxide, scientists reported in the journal Nature Geoscience.

Diesel combustion in trucks, buses and cars emit a lot of black carbon. The particulate air pollution also commonly comes from burning firewood, indoor cooking, and biomass burning.

Using data from satellites, aircraft and surface instruments, the scientists found that the warming effect of black carbon amounts to 0.9 watts per meter squared. That’s at least two times greater than estimates put forth by the United Nations-sponsored Intergovernmental Panel on Climate Change (IPCC), the researchers said.

Besides making things look dirty, black carbon particles contribute to the retreat of glaciers and pose a public health risk, said V. Ramanathan, co-author of the study and atmospheric scientist at the Scripps Institution of Oceanography at the University of California, San Diego.

A major difference between black carbon and carbon dioxide is in their respective life spans, Ramanathan said. Carbon dioxide molecules can stay in the atmosphere for more than 100 years after being released, whereas black carbon only stays up there for about 10 days.

Black carbon pollution is a problem worldwide, the scientists said. China and India are responsible for between 25 and 35 percent of black carbon in the global atmosphere, mostly from burning wood and cow dung for cooking and using coal for heating. Countries that extensively use diesel fuel for transportation are also responsible for a lot of black carbon pollution.

While policy action should be taken to reduce black carbon emissions, it would be a “catastrophic mistake” to think that’s enough, without also addressing the problem of carbon dioxide emissions, Ramanathan said. "We have to do both," he said.

–Elizabeth Landau, Associate Producer, CNN.com

Filed under: climate change

CNN's Severe Weather Expert Chad Myers weighs in on the forecast for some very bad tornado weather - and then tells us what it all means:

A battle between hot and cold begins tonight in the western high plains and continues well into the Ohio Valley through Friday. Winter is trying to hold on as the heat and humidity of summer are trying to push the cold air back into the Arctic. Obviously, the warm air will eventually win, but tonight and tomorrow a blast winter will push all the way to the Gulf of Mexico. A severe weather outbreak will occur in the path of the clashing air masses.

The Storm Prediction Center expects a good chance of tornado activity today and tomorrow. This map shows the greatest risk for Thursday over a large area of the Lower Mississippi River Valley, including Memphis and St. Louis. Source: NOAA

Now there are many more ingredients necessary to make severe weather like tornadoes. You can't make bread from flour and water....but it'll make a good base. Same here....temperature clash will make the base and a jet stream, a vorticity max, a low level jet, and lots of humidity will be the yeast, eggs, salt and oil.

Technically speaking for the weather inclined, here's the forecast from the Severe Storms Forecast Center (NOAA). I'll translate at the end:

"INGREDIENTS ARE QUICKLY COMING INTO PLACE TO SUPPORT A SIGNIFICANT PERIOD OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN PLAINS. IN RESPONSE TO THE APPROACH OF THE DEEPENING COLD TROUGH OVER THE SWRN U.S...A STRENGTHENING LOW LEVEL JET IS RAPIDLY TRANSPORTING QUALITY GULF MOISTURE INTO TX AND OK.

STALLED FRONTAL ZONE FROM SRN AR TO SWRN TX WILL RETURN NWD THIS AFTERNOON POSSIBLY TO RED RIVER VALLEY BY THIS EVENING. WITH DEWPOINTS RISING THRU THE 60S MLCAPES AOA 2500 J/KG COUPLED WITH STEEP MID LEVEL LAPSE RATES AND STRENGTHENING DEEP LAYER VEERING SHEAR PROFILES WILL BE SUPPORTIVE OF TORNADIC SUPERCELLS.

LARGE SCALE ASCENT IS INCREASING WITH APPROACH OF DIFFLUENT UPPER JET. NEAR SURFACE BASED SEVERE THUNDERSTORMS EXPECTED TO DEVELOP BY MID/LATE AFTERNOON. STORMS THAT DEVELOP VICINITY OF THE WARM FRONT WILL QUICKLY BECOME SUPERCELLS GIVEN THE QUALITY OF THE AIR MASS AND STRONG DEEP VEERING SHEAR PROFILES.

LARGE HAIL...AND TORNADOES ARE EXPECTED WITH STORMS THAT DEVELOP VICINITY WARM FRONT THIS AFTERNOON. THE POTENTIAL OF LONG LIVED SUPERCELLS AND STRONG TORNADOES WILL BE POSSIBLE AS STORMS TRACK ACROSS N TX INTO SRN OK THIS EVENING VICINITY SURFACE FRONTAL ZONE.

SURFACE LOW DEVELOPS SWRN TX THIS AFTERNOON AND THEN DEEPENS NEWD INTO OK TONIGHT AS THE INTENSE TROUGH BECOMES NEGATIVELY TILTED AND MOVES INTO SRN HI PLAINS BY 12Z THU. SEVERE THUNDERSTORMS WILL REDEVELOP BACK IN TX PANHANDLE AND SWRN TX TO E OF DRY LINE/COLD FRONT OVERNIGHT. GIVEN THE STRENGTH OF FORCING...A SEVERE SQUALL LINE WITH ENHANCED WIND DAMAGE THREAT WILL BE MOST LIKELY MODE. HOWEVER EMBEDDED SUPERCELLS AND TORNADOES ARE ALSO LIKELY AS THE SHEAR AND INSTABILITY WILL STILL BE MORE THAN SUFFICIENT...EVEN WITH THE NORMALLY UNFAVORABLE TIME OF DAY.

DURING THE AFTERNOON AND EVENING ADDITIONAL STRONG/SEVERE THUNDERSTORMS WILL DEVELOP VICINITY FRONTAL ZONE FURTHER E ACROSS AR/NRN LA. WHILE SHEAR WILL BE MARGINALLY FAVORABLE FOR ORGANIZED STORMS...MDT INSTABILITY WITH MLCAPES AROUND 2000 J/KG AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT AT LEAST MULTICELLULAR STORMS WITH LARGE HAIL POTENTIAL."

Wow, so what does all that mean? Let's go piece by piece.

First Paragraph: Ingredients are coming together....you can have humidity, cold air, a jet stream, and all of the other parameters of severe weather, but if they are not in the right alignment, you will only get rain. In this case the "cold trough" (a dip in the jet stream) and the "Low Level Jet" (a strong wind from the south at 2000 feet) are working together.

Second Paragraph: A stationary front across central Texas will move north tonight to the Red River. This move will bring humidity to the north...closer to the cold air coming in from the north. The rest of the paragraph refers to the profile of the atmosphere with respect to potential volatility of a developing storm.

Third Paragraph: "Large scale ascent" means the air at the surface is rising to higher levels. Rising air makes clouds ...sinking air makes clear skies. "Diffluent upper jet" means the air at, let's say 30,000 ft., is diverging...moving apart...this movement apart causes lower pressure....lower pressure draws more air up from the surface...(remember rising air causes clouds...and in this case storms). "Storms that develop near the warm front will quickly become supercells" - The air mass by the warm front is warm and humid and the winds aloft change direction with height. This causes rotating thunderstorms that are not in a line with other storms and they are called supercells.

Fourth Paragraph: Self explanatory.

Fifth Paragraph: A Low pressure area (rising motion) develops in southwest Texas and gets stronger as it moves into Oklahoma tonight. The words "negatively tilted" refer to the shape of the jet stream. "Positively tilted" troughs will produce less severe weather. See this link: http://www.theweatherprediction.com/habyhints/127/

A "dry line" is a dry air "front" that blows out of the high plains east of the Rocky Mountains. It pushes air up just like a cold front.

Sixth paragraph: Other storms will develop over the Ark-La-Tex, but will not contain large tornadoes, but will contain hail.

That's just for tonight and tomorrow morning. More tornadoes are likely Thursday and Friday.

Filed under: Tornadoes • Weather

Check out these new views of Mars' moon Phobos, taken by the Mars Reconnaissance Orbiter (MRO) back on March 23.

Source: NASA/JPL-Caltech/University of Arizona

The two images were shot 10 minutes apart. At the time, MRO was a couple hundred miles above the surface of Mars, traveling 7,800 mph. Phobos, which is just 13.5 miles wide, was about 4,000 miles away. Given the distance, the clarity and resolution of the images is remarkable.

The principal feature on the moon is undoubtedly the Stickney crater, on the bottom right in these pictures. It's about 5.5 miles in diameter, and was formed by a very large impactor. Also very noticable is the blue material around the rim.

"Based on analogy with material on our own moon, the bluer color could mean that the material is fresher, or hasn't been exposed to space as long as the rest of Phobos' surface has," said Nathan Bridges with NASA's Jet Propulsion Lab, in a statement.

Mars also has a second, even smaller moon, Deimos. Scientists think the moons might be asteroids from the asteroid belt that got caught in Mars' gravitational field. If so, they are different from Earth's moon, which many scientists think formed from shattered rock jettisoned into space when Earth was hit by a massive asteroid or comet shortly after the planets formed 4.5 billion years ago.

–Kate Tobin, Senior Producer, CNN Science & Technology

Filed under: Mars • NASA • Space

Want to know exactly where in the U.S. the biggest belches of fossil-fuel carbon dioxide are emitted? Researchers at Purdue University have just released a map that shows you, in more detail than ever before.

Source: Purdue University

The Purdue scientists say their system, called Vulcan, is more accurate than earlier inventories of CO2 sources, because it's based on actual emissions of greenhouse gases, as measured by the EPA and other agencies, rather than estimates.

Another reason it's more accurate, they say, is because it uses data collected every hour at local levels, rather than monthly on a state-by-state basis. The data are broken down into areas as small as 6 miles across.

Vulcan takes into account carbon dioxide from all sources that burn fossil fuels like gasoline or coal: vehicles, factories, home heating, power plants.

The Purdue researchers say when they combined a huge amount of data into a format that's easy to grasp, they got some surprises.

"For example, we've been attributing too many emissions to the northeastern United States, and it's looking like the southeastern U.S. is a much larger source than we had estimated previously," says Kevin Gurney, the leader of the project, in a written statement.

At first glance, you may think that the CO2 emissions follow the roadways with amazing precision – for instance, along I-80 in northern Nevada. But that's actually because the researchers built the map that way; all the emissions attributed to cars and trucks were shown hovering over the major roads.

Check out the little patch of clean air in upstate New York, close to the Vermont line: that's the state's 6-million acre Adirondack Park, created in 1892.

The Purdue researchers have also posted some videos from the Vulcan project on YouTube, including a cool animation of CO2 emissions over months, which are shown billowing off the map in a big brownish-purple cloud.

The researchers say because of the accuracy of the Vulcan tool, it could help policy-makers come up with more precisely targeted ways to battle greenhouse gas emissions.

And they say the project is not about assigning blame for greenhouse gases. "What Vulcan makes utterly clear is that CO2 emissions cannot be exclusively affixed to SUV drivers, manufacturers or large power producers; everybody is responsible," Gurney says in the press release. "It's not about politics. It's about doing good science and solving the problem, and we can all be a part of that."

The project included researchers from Purdue, Colorado State University and Lawrence Berkeley National Laboratory. It was funded by NASA and the Department of Energy.

–Kate King, Writer, cnn.com

Filed under: climate change • environment

I sat down a few hours ago to fire off a quick blog about today's Webby Award nominations... but it's been hard tearing myself away from surfing the nominees.  There's lots of material you'll want to forward to friends. 

For the past twelve years, a group of Internet industry experts and luminaries have handed out the Webby Awards.  In 1997, the inaugural honors were bestowed upon a handful of Web sites in 15 categories.  Today, there are more than 100 categories ranging from "Activism" to "Weird," covering not only Internet sites but interactive advertising, online videos and mobile phone entertainment.

You've probably already seen a number of the nominees.  A lot are heavily viewed, like Facebook, Flickr, and yes, cnn.com.  And I must mention that Anderson Cooper 360 is up for best fan site.  (Sadly, SciTechBlog is not mentioned for best blog - go figure!)  And a lot of the nominees have probably graced your inbox, like the 30-second Bunnies Theatre version of Brokeback Mountain or the angst of Lonelygirl15.  But you probably haven't seen many of the nominees, like a video of breast reconstruction after a mastectomy (and you may not want to!)

The Webby Award honorees are nominated and chosen by a 550-person judging academy called the International Academy of DIgital Arts and Sciences.  Members include "Simpsons" creator Matt Groening, "Father of the Internet" Vinton Cerf, and movie mogul Harvey Weinstein.  But you can also be a judge in The Webby People's Voice Awards.  These honors will be given in more than 70 categories - get your vote in by May 1.

Winners will be announced May 6, and honored at two separate ceremonies in New York City - June 9th for The Webby Film and Video Awards and June 10th for The Webby Awards Gala.  Winners are allowed just five words to deliver their acceptance speeches.  One of the most memorable is Al Gore's Lifetime Achievement Award speech in 2006 - "Please don't recount this vote."  You can browse past acceptance speeches on the Webby Web site.

Okay.  Now back to Cute Overload.

–Diane Hawkins-Cox, Senior Producer, CNN Sci-Tech Unit

Filed under: Internet

A new space station crew blasted into space through clear blue skies today from the Baikonur Cosmodrome in Kazakhstan. The Soyuz spacecraft carried Expedition 17 crew members Sergei Volkov, who will be the new station Commander, and Flight Engineer Oleg Kononenko. They were joined by South Korean space tourist So-yeon Yi, who at age 29 is the youngest woman ever to fly in space. Volkov is the son of veteran cosmonaut Alexander Volkov.

Source: NASA TV

Unlike NASA, Roscosmos, the Russian Space Agency, provides live TV pictures of the crew in the cockpit during the ascent into space. So-yeon Yi could be seen with a broad smile on her face, repeatedly giving the "thumbs-up" sign to the camera.

Once in space, it takes the Soyuz a couple of days to "catch up" to the International Space Station, so docking will not happen until Thursday.

Meanwhile, Expedition 16 crew members Peggy Whitson and Yuri Malenchenko are preparing to wrap up their six-month tour of duty and will return to Earth with So-yeon Yi in the Soyuz on April 19. Expedition 16 Flight Engineer Garrett Reisman will remain in orbit and become part of the Expedition 17 crew. Commander Whitson was the first female station Commander and oversaw one of the busiest periods to date in space station assembly.

The Expedition 17 crew is expecting visitors in early June when astronauts aboard the space shuttle Discovery come calling to deliver and install another piece of the Japanese Kibo Module to the station. After that, things will quiet down for a while in terms of station assembly, while the shuttle program turns its attention to flying the final Hubble servicing mission, currently targeted for October.

–Kate Tobin, Senior Producer, CNN Science & Technology

Filed under: International Space Station • NASA • Space • Space Tourism

We all know one fish and one fish make two fish, but recent evidence suggests that fish may know that too. In fact, mosquitofish can count up to four, according to results from a team of researchers led by Angelo Bisazza of the University of Padua in Italy.

In each test, a lone female mosquitofish had two options for shoals to join, each containing between two and eight other fish. The results showed the lone fish would usually choose the shoal that was larger by just one fish, consistently picking the shoal of four fish over the one with three, and the shoal of three fish over the one with two.

But when one of the choices was larger than four fish, the fish could no longer discriminate. Monkeys and one-year-old children exhibit the same limit, Bisazza said.

Experiments examining what the fish would do when confronted with larger numbers found that, for shoals of more than four fish, they could still tell the difference between the quantities if there was at least a 2:1 ratio. That is, they would choose a shoal of eight fish over the one with four, but they could not discriminate between a shoal of 12 and a shoal of eight. These results are consistent with mathematical abilities observed in birds and mammals.

Similar performance has also been observed in people who speak languages that contain limited vocabularies for numbers, Bisazza said. For instance, speakers of the Amazonian language Munduruku only have words for numbers from one to five, and do not have names for numbers beyond that. Though they are able to solve nonverbal number tasks involving quantities up to 70, in exact arithmetic they do not do well with numbers larger than four or five, he said.

Besides fish, other non-human creatures that have shown at least some rudimentary mathematical abilities in studies include chimpanzees, macaques, dolphins, dogs, parrots and pigeons.

"Many researchers are now convinced that mammals and birds may share common mechanisms to count objects and compare quantities," Bisazza said.

–Elizabeth Landau, Associate Producer, CNN.com

Filed under: Animals • Mathematics

It seems there's virtually no dilemma plaguing humanity that hasn't been studied by some scientist, somewhere.

A torn poster in Serbia-Montenegro illustrates the "wallpaper problem." Source: DIMITAR DILKOFF/AFP/Getty Images

Case in point: You know how, when you try to tear down old wallpaper, or pull a label off something, it invariably peels on a diagonal line instead of coming off straight, so you end up with a point still stuck to the surface?

Well, apparently that really bothered a team of scientists from MIT, the Centre National de la Recherche Scientifique in Paris, and the Universidad de Santiago, Chile.

"This shape is really robust, so there must be something fundamental going on that gives rise to these shapes," said Pedro Reis, a mathematics instructor at MIT.

Now, the researchers have explained the physics of what they call "the wallpaper problem," according to a press release from MIT.

The team analyzed how the stiffness and toughness of a material being pulled off a surface interacts with the strength of the adhesive holding it in place.

The scientists say energy builds up along the line where the strip of wallpaper (or whatever) is peeling from the wall, and one way for the energy to be released is for the strip to become narrower – so it does.

The team also came up with a way to predict the angle at which a given piece of wallpaper will tear.

The scientists say the same thing happens when you peel a tomato or a grape. It's not clear whether any of the researchers actually sat around peeling grapes.

The research could actually have practical applications in industries where the properties of sticky films are important.

The study was published in the journal "Nature Materials."

–Kate King, Writer, cnn.com

Filed under: Materials • Physics

.... or at least the other side of our world.   

 I just got back from a week in Beijing, as part of a program for American journalists to share their experience with our Chinese colleagues on reporting on science and the environment.  I'd never been to China, nor to anywhere else in Asia, so every part of this was a new experience. 

Looking across Tienanmen Square toward Chairman Mao’s tomb on what I thought was a smoggy day. My hosts said the day was “not too bad.”

China's capital city, lately swelling to a population of nearly 20 million, is basking in the glow of an economic boom - all while sweating in anticipation of its turn in the world's spotlight this August during the Summer Olympic Games.    After a few days to hit the obligatory tourist sites, and shake off the inevitable jet lag, we got down to business.

The journalists were from several divisions of CCTV, China's massive, state-run national broadcaster.  We met documentary producers, staffers from CCTV's English-language network, and from "Greenspace," China's nightly, prime-time environmental news show.    Five nights a week in prime time?  A potential audience bigger than the population of the United States?   Sounds pretty good - in fact, it sounds like a much better deal than a Science and Environment Guy can get here in the West.  The message has come down from on high:  Green is the new Black in Red China.

Of course, it's not that simple:  The "on high" is the Central Government, and the Central Government doesn't let you say Bad Things about the Central Government on the Central Government's TV Networks.  When I showed a portion of our recent "Broken Government" special on US failures in environmental protection, I was politely told that it would be naive to think that kind of thing could fly in China.  In fairness, some of the questions we received sounded a little naive from a Western perspective.  (My favorite:  "We know China has the world's world pollution problems, but what advice can you give us to turn this into a positive news story?").

Simple answer:  Clean it up.   Except that there's no such thing as a simple answer.  China has at least 20% of the world's population, but only 7% of its fresh water.  Much of that is too polluted for human use.  Much of the rest is drainage from the snowpack and glaciers of the Himalayas - now in drastic decline due to global warming.

 China's running out of water.   And land.  And acceptable air.  And it's rapidly caught up to the US in greenhouse gas emissions, with the prospect of huge increases as its economy continues to grow.  Importing the rest of the world's waste is a growing revenue stream for China, even while the actual streams often run in pastel colors from factory and mine runoff.

Is there any good news here?  Maybe.   China's time of reckoning with a growing environmental crisis is nicely timed for its coming-out party at the Olympics in August.  But will the spirit of the "Green Olympics" survive after the torch goes out?  Stay tuned.

- Peter Dykstra, Executive Producer, CNN Science and Technology

Filed under: Uncategorized

Perhaps it's only a coincidence that on this April Fool's Day, Google has announced an extraordinary initiative to improve your e-mail experience.

Eric Schmidt, chairman and CEO of Google, which unleashed its annual April Fools initiatives today.

With Custom Time, you can change the time stamps on up to ten e-mails per year to make it look like you didn’t miss deadlines, birthdays, anniversaries, etc. But wait! If you make it so that an e-mail was sent in the past, wouldn't that have affected subsequent events? Apparently Google can even smooth out related kinks with its "e-flux capacitor" to "resolve issues of causality." One user apparently told Google, "I used to be an honest person; but now I don't have to be."

Even more exciting, Google claims to have teamed up with Virgin Group to launch Virgle, the first human colony on Mars. You can even apply to join the venture by answering the questionnaire. You'd better think really hard about how you would respond in tough situations. What would you do if "unexpectedly confronted with the emergence of a bewilderingly alien and frighteningly advanced Martian life form" that "appeared bent on killing" you if you "failed to quickly and effectively communicate my peaceful intentions and potential value to its civilization"? Once you've got that down, submit a 30-second video through YouTube explaining why you want to live on Mars. It's just that simple, fool.

–Elizabeth Landau, Associate Producer, CNN.com

Filed under: Mars • Space