How much would it cost to dim the sun a little with a dusty layer of aerosol particles in the stratosphere? The service comes for free if you can find an obliging volcano, like Mount Pinatubo, but they can hardly be relied on in the long term. Some schemes for doing it to order, though, could be pretty cheap, according to an analysis by Alan Robock and colleagues at Rutgers.

In the 1990s a National Research Council panel in the US estimated the costs of delivering dusty particles ito the stratosphere from big guns like those on old battleships. The panel came up with a figure of $30 billion a year: a lot cheaper than most proposals for carbon cutting, but still a fair chunk of change. Robock looked at the costs of getting into the stratosphere by the more orthodox means of aircraft. Near the poles, where the bottom of the stratosphere comes closest to the ground, big aircraft like Air Force tankers can get high enough to inject aerosols. Robock calculated that getting a billion tonnes of sulphur up to the stratosphere would take just three flights a day by each plane in a nine or fifteen plane squadron (nine if you use KC-10s, which are basically LD11 TriStars, fifteen if you use KC-135s, derived form the original design of the Boeing 707; plane spotting interlude ends here). That represents a purchase price of a billion or so and operational costs of well under $100 million.

If you want to take the sulphur higher, Robock says, think about F15-C Eagles (now we're talking...). With the smaller planes you need something more like a whole wing than a squadron -- 167 planes doing three flights a day. That's a purchase cost of about $6 billion, and an ops cost more like a billion a year.

Continue reading "AGU: Geoengineering costs" »

Posted by Oliver Morton at 08:04 PM | Permalink | Comments (1) | TrackBacks (0)

Cities often take a lot of heat in environmental discussions. All that pavement and pollution damages human lungs and warms the climate. But a few sessions this week suggest that cities may be part of the greenhouse solution.

First a few challenges: Cities are carbon bombs. In the United States, urban areas cover less than 3 percent of the land area but account for 70 to 80 percent of the carbon dioxide emitted by fossil fuel burning. And cities are growing. By 2030, 60 percent of the world population will be urbanites.

Now some of the good news: Cities are carbon vaults. They and other human settlements store a surprising amount of carbon—to the tune of 18 petagrams in the United States. That’s almost 10 percent of the total land carbon storage in the conterminous US, according to Galina Churkina of the Max-Planck Institute for Biogeochemistry in Germany. The carbon is locked in everything from landfills to the books lining library shelves.

Question: What has a higher carbon density--a city or a tropical forest?
Answer after the jump.

Continue reading "AGU: Cities as carbon sinks" »

Posted by Richard Monastersky at 05:02 PM | Permalink

This according to Stanford University researcher Mark Jacobson, who has compared various energy technologies in terms of not only greenhouse gas emissions but also conventional pollutants, land use, water resources and more. Speaking after a news conference here, Jacobson said he is trying to provide a more holistic analysis of the various energy options. "There's a lot of misinformation out there," he said.

A few of the key results follow:

Life cycle emissions -- Wind and solar thermal come out on top; tidal, wave and hydro all beat out solar photovoltaics, geothermal and nuclear, thanks to energy spent on equipment and installation; coal was the big loser, even with carbon sequestration (CCS), thanks to energy spent on mining and transport.

Mortalities due to air pollution from US vehicles -- For gasoline, projected deaths drop from 20,000 to 15,000 annually in 2020 due to improved technology and air quality standards. That figure would remain steady or perhaps even rise if ethanol (corn or otherwise) made up 85 percent of the transport fuels. Assuming electric transport takes off, wind reduces mortalities to almost zero, although the full suite of renewables fared almost as well. Coal with CCS would cut mortalities by upward of two-thirds. Nuclear falls between coal and renewables (assuming non-proliferation regimes hold and there aren't any explosions).

Footprint required to power US vehicle fleet -- Accounting for the base of the turbine alone (not roads), wind could power the entire vehicle fleet using less than 3 square kilometers of land. Corn ethanol and concentrated solar power are the big losers, with each requiring a chunk of land that is larger (and perhaps significantly larger) than the state of California.

Water usage -- Wind, solar photovoltaic, geothermal, tidal and wave all come in around zero; coal, nuclear and concentrated solar do well; hydropower gets a poor rating, thanks to evaporation rates from reservoirs (Jacobson divvies up the losses among energy and other uses). But the clear loser is ethanol, whether the source is corn or something else.

Posted by Jeff Tollefson at 11:02 PM | Permalink

You won’t find his name in the program, but his teacher and colleagues think Andy Olander – a 13-year-old student from Albuquerque, New Mexico – may be the youngest poster presenter at an American Geophysical Union meeting. Olander and five “colleagues” at the James Monroe Middle School developed a project on comparing the length of the sun’s shadow in summer and winter at different locations globally. Over time, “the shadow team” grew as they tapped the knowledge of professional scientists at the US Geological Survey and the Raytheon Polar Service in Colorado. Then their science teacher, Turtle Haste, and Mary McGann of the USGS office in Menlo Park, California, struggled with how to credit the abstract for the AGU autumn meeting poster. Initially, they assumed he was too young to be an author. Then they checked around and found there appeared to be no lower age limit. But by then, the report was accepted for presentation without any of the student names as authors. The eighth-grader then got the call to describe the professionally done poster’s graphs on shadow length. Dressed smartly, he looked viewers in the eye and verbally projected well – something some of his more senior presenters down the row weren’t doing. The AGU public affairs office wasn’t sure if he indeed was the youngest. It even was a bit of a problem for them to determine who to ask if there Was a lower age limit. They are checking. We’ll see. And we may see Andy again. “It’s really fun,” he says.

Posted by Rex Dalton at 08:24 AM | Permalink

Five years ago, Bill Ruddiman came to the AGU with a bold idea: That humans caused significant global warming with the advent of agriculture 8,000 years ago, long before our ill-fated love affair with fossil fuels started in the Industrial Revolution. That proposal has prompted dozens of studies, a book, and intense debate, so researchers gathered Wednesday afternoon to assess the state of the evidence.

Ruddiman’s basic argument goes like this: Although the climate has cycled through a series of ice ages and warm interglacial periods for more than a million years, none of those warm spells looks like the one we’re in. In all previous cases, carbon dioxide and methane concentrations peaked just after the preceding ice age ended and then levels of those greenhouse gases dropped until the planet slipped again into a new glacial epoch. The planet seemed to be following the same routine since the last ice age ended about 11,000 years ago. But then something funny happened. After falling for a few thousand years, carbon dioxide levels started to rise about 8,000 years ago and methane values swung upward 5,000 years ago.

As an explanation, Ruddiman suggests that carbon dioxide concentrations started to grow when early farmers cleared vast stretches of forest to plant crops, thus reducing the planet’s ability to sop up carbon from the atmosphere. Later, when people learned how to irrigate rice 5,000 years ago, the paddies created for that purpose led to a jump in methane emissions. Those changes prevented the planet from slipping into an ice age, he suggested.

At Wednesday’s session, Ruddiman took the provocative stance of saying that the case is closed.

Continue reading "AGU: Did the first farmers stave off an ice age?" »

Posted by Richard Monastersky at 07:45 AM | Permalink

Roughly a thousand people squeezed into a hall to see James Hansen talk this afternoon. They occupied all of the seats, then lined up along exterior walls. The aisles filled up with squatters, and dozens stood on tippy-toes outside trying to get a peak. At one point Mascone Center organizers forced dozens of people out, threatening to call the fire marshal and shut down the talk altogether. Then they gave up, allowing this intrepid reporter to sneak in.

There's some rumbling within the scientific community about the way Hansen is mixing his science, as director of NASA's Goddard Institute for Space Studies, with his activism, but clearly this has not eaten into his star power. Hansen talked about his latest research, which suggests that goals of limiting atmospheric carbon dioxide levels to 450 parts per million are too tame. He is advocating an upper limit of 350 - 35 below current levels - at a time when many are scratching their heads trying to figure out how to stabilize at 450, or even 550.

To illustrate the dangers, he talks about the "Venus Syndrome," which is essentially runaway warming that eventually boils off the oceans and makes the planet uninhabitable. At least with a snowball earth scenario - which is, admittedly, equally bad for humanity - greenhouse gases pumped into the atmosphere by volcanoes would eventually trap enough heat to melt the ice and start the whole experiment over again. "There is no escape from the Venus Syndrome," he says.

How close we are to the brink is not clear. "Our model blows up before the oceans boil," he says, but the results suggest that runaway warning could be a factor of 5-20 beyond the current climate forcing.

Continue reading "AGU: 'Is the planet really just doomed?'" »

Posted by Jeff Tollefson at 02:02 AM | Permalink | Comments (1) | TrackBacks (0)

With the many concerns over climate change, scientists are submitting a growing number of reports on extreme weather events – cyclones, droughts, or gales of 100 mph winds. These abstracts provide access to details not easily available to researchers, historians or journalists; particularly, if the events occur in countries that sometimes control the media. Consider reports of a devastating ice storm in south China early this year. A team at the Research Institute of Subtropical Forestry in Zhejiang presented reports at the American Geophysical Union meeting on the widespread damage. The extent of the economic impact of the harsh and unexpected freeze is just now being tabulated by researchers like the Institute’s Benzhi Zhou; Zhou and colleagues were assisted in San Francisco by Lianghong Gu of the Oakridge National Laboratory in Tennessee. Zhou’s report noted the damage: at least 125 people dead; costs of $22 billion yuan; more than 19 million hectares of forests in 19 provinces damaged; more than 14 million hectares of crops (oilseed rape, vegetables, fruits) affected; and 30,000 protected wildlife threatened. The team offered suggestions for damage control. But they aren’t sure the government is listening, as the gravity of the event isn’t fully acknowledged or appreciated.

Posted by Rex Dalton at 01:31 AM | Permalink

It may be a bit of poetic fancy, but aeronomers (those who study the upper atmosphere) are talking these days about watching the earth breath. More specifically, a few researchers think they have discovered a “breathing mode” of the upper atmosphere—during which the planet’s gaseous blanket expands and contracts regularly about once every 9 days in a previously unrecognized cycle.

The evidence comes from satellite observations of the thermosphere, the region of sky extending from 85 kilometers to roughly 1,000 km above the surface. Data obtained from Germany’s CHAMP satellite indicate that the density of the thermosphere doubles about every nine days, according to Jeffrey P. Thayer of the University of Colorado at Boulder, one of the researchers who presented data on this newly observed pattern. Geoff Crowley, president of Atmospheric and Space Technology Research Associates in San Antonio, Texas, found a similar 9-day cycle in chemical data taken by the Global Ultraviolet Imager on NASA’s TIMED satellite. Measurements made by the SABER instrument on the same satellite also revealed the 9-day cycle, reported Martin G. Mlynczak of NASA's Langley Research Center.

Aeronomy researchers were well aware of longer cycles, such as the 27-day pattern that corresponds to the rotational period of the sun, but nobody had looked for shorter patterns, said Thayer. He and his colleagues hypothesize that the sun is also driving the 9 day cycle, as well as some weaker, even shorter period, ones that have emerged from the data.

And who says there’s nothing new under the sun?

Posted by Richard Monastersky at 12:31 AM | Permalink

Here are some other blogs and posts coming from AGU.
Erik Klemetti is blogging on matters volcanic at the suitably titled Eruptions. An interesting tidbit:

the Kasatochi eruption released the most sulfur dioxide into the atmosphere since the 1991 Pinatubo eruption

"short of being on Mars, picking up a piece of rock and seeing fossil impressions of raindrops on it, this is the best evidence for actual rainfall on Mars in the past."

"Everywhere we look, we're seeing x-rays and gamma rays flying out of thunderstorms and lightning," said Joseph Dwyer, a physicist at the Florida Institute of Technology and lead author of the study. "The gamma rays coming out of thunderstorms are so intense we can measure these 600 kilometers away and so bright that it almost blinds the spacecraft."

I was struck by something that one of the Cassini spectroscopists, Tom McCord, said as he opened his talk: that even though Cassini has now completed its primary mission at the Saturn system, which included dozens of Titan flybys over four years, and has now gone on to an extended mission, "the science is the least mature of any [extended] mission I've ever worked on." It's not for lack of effort; it's just that Titan is fiendishly difficult to study.

Decision-makers need information on a local and regional scale that climate models can't always provide. So UCAR-member universities have started discussions with decision-makers about their requirements; these discussions were extended to other academics at an AGU session.
"We need more user/stakeholder-driven research, not curiosity-driven research," agreed Jonathan Overpeck of the University of Arizona, who has been considering what a national climate service could offer decision-makers.

Posted by Oliver Morton at 11:27 PM | Permalink

On Thursday and Friday there will be some sessions on "geoengineering" -- intervening in the climate deliberately in an attempt to counteract greenhouse warming. One of the presentations, previewed at a press conference today, was an idea for a way of cooling the earth I hadn't come across before: stripping off some of the high cloud.

David Mitchell, of the Desert Research Institute in Reno, points out that cirrus clouds warm the earth by letting light come in but detaining longwave radiation on its way out. (Clouds in the lower atmosphere are cooling, because they reflect back sunlight more than they trap heat). To get rid of them he suggests, a little counterintuitively, adding particles that will encourage water vapour to freeze into ice crystals.

You'd think that would make more clouds, and you would be sort of right. But the processes by which ice grows around these nuclei will outcompete the processes that make up the ice particles normally found in cirrus clouds; instead of getting lots of little ice particles in a cloud you'll get a few bigger particles -- big enough to fall down to the lower atmosphere.

The nuclei would make some clouds where you wouldn't otherwise get them, because they will allow particles to grow in places where there is not enough water vapour for cirrus clouds to form normally. But the net effect, according to Mitchell's models, is to dry the upper troposphere out, decrease the amount of cirrus and cool things down.

How well it would work in practice is unknown. It would almost certainly have some effects beyond just letting more outgoing radiation to leave the planet unmolested, and as yet no one knows what those might be. Mitchell wants to do some more model work to address some of those questions, and then -- perhaps, maybe -- some small-scale experiments. Unlike the much more widely discussed idea of putting aerosols into the stratosphere, the cirrus-busting technique could be tried, and indeed continued, at a regional level, if that was desired; it could also be stopped in days if it was suddenly not wanted.

So if you think geoengineering is worth doing research on, then it looks like this idea should be added to the list for a preliminary look-see. If you don't, it's another thing to worry about.

I'll try and blog a bit more about geoengineering tomorrow.

Posted by Oliver Morton at 10:19 PM | Permalink

The power of the HiRise camera on NASA's Mars Reconnaissance Orbiter continues to amaze. Its latest trick, PI Alfred McEwen just told a session here on MRO results, is to look at buried ice in Mars's mid latitudes.

Seeing ice that's half a metre or so beneath the surface of flat plains might seem hard even for eyes as sharp as HiRise's. The trick is to spot small impact craters just after they have formed. Small craters get made on Mars at a reasonably high rate, because little impactors that would just be pretty lights in the sky on earth make it all the way through Mars's thin atmosphere. So HiRise is already spotting craters that have been made since it got to Mars a few years ago. In one of these, which they know was made in the summer of 2008, HiRise saw a couple of little white dots.

Because the craters were less than 5 metres across, the McEwen and his colleagues reckoned that this put the white dots about 50 centimetres down. They've now found four other more or less contemporary craters on the Arcadia plain which have similar white patches, and the spectrometer on MRO, CRISM has confirmed that the largest white patch is water. Over time the patches fade as the ice turns to water vapour, or gets dusty, or both.

There's nothing new about finding water on Mars, and I haven't yet had a chance to find out whether ice in these latitudes (about 45 degrees north) is a surprise to people who think about such things. But as McEwen pointed out, it makes it all the more likely that Viking 2, which landed at a similar latitude not that far away, might have been sitting on ice, if only it had been able to scrape down a little farther. It also means anyone with future interest in ice would not necessarily need to go as far north as Phoenix did.

Posted by Oliver Morton at 05:32 PM | Permalink

Nature's Rich Monastersky has a full story on what happened in the Arctic this summer - including melting in Greenland and methane bubbles in Siberia -- available here.

Posted by Alex Witze at 02:34 PM | Permalink

The US Climate Change Science Program released its latest report at the AGU meeting today, taking a deeper look at several potential disaster scenarios that fall under the rubric of "abrupt climate change." The outlook is mixed, so we'll start with the good news, move through the bad and end with the ugly.

So. A rapid and massive methane release from sea floor or permafrost hydrates is unlikely this century, which is good news as methane is, pound-for-pound, a much more potent greenhouse gas than carbon dioxide. [Editor's note: see related story here.] Same story for the prospect of a halt to the ocean circulation (portrayed, rather loosely, by Hollywood) that pumps warm surface water into the north Atlantic, which in turn provides much of Europe with a surprisingly warm climate given its latitude.

The bad news is that global warming is likely to increase the chances of "severe and persistent" drought in the southwest United States (this report focuses on the US, though its implications are in many cases global). In fact, we may already be witnessing just this. Or not. Things like tree-rings tell us that such droughts have happened independent of human-induced global warming, so it's tough to pin down what's driving the current drought. But modelling suggests that global warming will only make the situation worse.

And now for the ugly: Sea-level rise this century is likely to "substantially exceed" the 0.18 - 0.58 meter projections released by the Intergovernmental Panel on Climate Change last year. In truth, this isn't a surprise. Even when the IPCC released its report, observations of ice-sheet loss on Greenland and Antarctica had already led many to the conclusion that the numbers were overly conservative, but the IPCC found its hands tied by the cutoff date for science that could be included in the assessment.

This report comes courtesy of the US Geological Survey, which took the lead in producing the document. As mentioned, it is one of many under a program that has a long and at-times-controversial history. For a little background (and a taste of the aforementioned controversy), check an earlier post on our Climate Feedback blog. WWF also put out a statement on the report today.

Posted by Jeff Tollefson at 02:09 AM | Permalink

The downside of bumping into old friends and acquaintances, as you do constantly at a meeting like this, is that you will occasionally hear sad news. Today I learned that Steve Ostro of JPL had died at the weekend, of complications related to cancer. Steve was a pioneer in the radar mapping of asteroids, leading a team that got most of the firsts in this field. As he told David Chandler in our feature on near-earth asteroid hunting last summer:

Observations of near-Earth objects were growing ... and we started getting some radar opportunities on newly discovered objects. In 1979, I met all the asteroid people and got very enthused, and then I was pretty sold on asteroids and wrote my own observing proposals. Within a year I was basically doing that more than anything else.

Posted by Oliver Morton at 11:44 PM | Permalink

Nature reporter Rex Dalton has a full news story on the dinosaur extinction 65 million years ago -- and one woman with an alternative theory -- here.

Posted by Alex Witze at 10:20 PM | Permalink

Michael Jones, Google's "chief technology advocate," is ready to make a deal: Money for data.

In a rambling, philosophical and frequently humorous talk on the nature of information Monday night, he chided a room full of scientists for hoarding data and discoveries as they work on interpretations worthy of certain prestigious science journals. When that approach fails, the science often gets lost in any number of niche journals. The result is a "spiral of information death," he says, that can only slow scientific progress at a time when speed is needed.

"It's your business, not mine," he said. "But I live on the same planet as you, and I would like to see it all work."

His solution? Boost funding, and then require scientists tapping into these new funds to share their raw data and discoveries as they become available. That way the critical information is out there, and the discoverer can compete along with everybody else on the interpretation, which Jones believes would hasten competition and produce useful results in a more timely fashion. "The privilege of being paid to discover comes with an obligation to share with mankind," he said.

Without going into specifics, he said Google's philanthropic arm tends to think along these lines when scientists request money. He also said the Google team presented these ideas in a meeting with US President-Elect Barack Obama's transition team, which is mulling an expansion of the science budget. It wasn't clear what kind of reception they received.

The picture is undoubtedly a bit more complex than he suggests, of course, but Jones was out to provoke. Whether he convinced anybody is another question. His call for openness drew a sudden round of applause at one point - from a half-dozen people, give or take one or two.

Posted by Jeff Tollefson at 09:21 PM | Permalink

Cross-posted from Climate Feedback, on behalf of Olive Heffernan

This evening at AGU there was a special screening of Crude, a film about our love affair with petroleum– oil that is, black gold, Texas tea.

The documentary won Richard Smith of the Australian Broadcasting Corporation this year’s AGU Walter Sullivan Award for Excellence in Science Journalism, a prestigious prize for outstanding reporting that makes geophysical science accessible and interesting to the general public. In Crude, Smith explores the geological formation of oil, its discovery and ascendancy in society and the potentially catastrophic consequences of our absolute dependence on it. Ironically, the very conditions under which oil was originally formed – a greenhouse world with elevated CO2 levels – are exactly those that its consumption could return us to.

Smith does an excellent job of conveying how oil, formed from the compressed remains of tiny plants and animals, could cause the demise of the most sophisticated species to have ever lived. And although we may be running out of the stuff, its pervasiveness in society means that weaning ourselves off oil will be no mean feat. There are no clear estimates of exactly how much oil is left in the ground, but the overwhelming message in Crude is that there are easily enough fossil fuel reserves to radically alter our climate should we use them all.

Overall, well worth a watch…

Posted by Alex Witze at 08:34 PM | Permalink

Cross-posted from Climate Feedback, on behalf of Olive Heffernan

Over the past 24 hours, some 15,000 earth scientists descended on San Francisco for the annual Fall conference of the American Geophysical Union. Delegates were a dead give away at the airport and on the BART yesterday with their large poster tubes in tow. It’s my first AGU and it could be the jet lag, but I’m feeling slightly overwhelmed by the sheer size and number of parallel sessions; at any given time I could be at one of at least four climate-related talks and invariably find myself wondering why the session next door is receiving louder applause.

A number of talks today focused on the need for climate science to become less curiosity driven and more specific to the needs of stakeholders such as local authorities and natural resource managers.

This is a topic that’s been getting a lot of attention recently. Earlier this year, for example, scientists called for a billion dollar investment in climate computing facilities to enable regional scale climate predictions on decadal time scales. At a press conference this morning, scientists including Jonathan Overpeck from the University of Arizona and Jack Fellows of UCAR highlighted the importance of partnerships between universities and decision makers in enabling states and regions to plan for climate change.

Continue reading "AGU: Applied climate science" »

Posted by Alex Witze at 08:31 PM | Permalink

A vast room of poster presentations greeted thousands of scientists at the American Geophysical Union’s annual autumn meeting on Dec. 15 in San Francisco – including one offering an “experimental hydrology Wiki” website. The website was created last year by Theresa Blume of the University of Potsdam in Germany and Llja Tromp-van Meerveld of Simon Fraser University in Burnaby, British Columbia. While designed to meet a need they had as doctoral students, the website now is seeking more posted articles to assist a range of environmental researchers, from hydrology to fields like forest engineering. The website is: www.experimental-hydrology.net.

Posted by Rex Dalton at 07:11 AM | Permalink

Lots of interesting stuff from Titan on Tuesday (forgive late blogging -- my computer was knackered). The Cassini spacecraft has finished its primary mission, and its science team is understandably proud of its discoveries. What caught my eye, though, were three not-yet-quite-discoveries: things to follow up on with further data analysis and more observations in the extended mission.

Volcanoes! Robert Nelson of JPL talked about data from Cassini's infrared instrument, VIMS, which show what seem to be brightness changes in a couple of regions. Rosaly Lopes described radar images of the regions that seem to show lobate flows of some sort of stuff. Together, they make a case for cryovolcanism -- eruptions of water/ammonia lava. Here's the JPL press release. Not so fast, said Jeff Moore, a planetary geologist from NASA Ames happy to play devils advocate at the associated press conference. Things can look volcanic without being volcanic, he warned, and things can change their brightenss, too -- look at the wind streaks on Mars, for example. Listening to him it was hard to see the volcano case as beyond reasonable doubt. A nice bonus after the press conference was listening to Moore and Lopes discussing which of them was using Ockham's Razor better: Moore, who was suggesting that everything on Titan can be explained with just the three surface and atmospheric factors known to be at play (wind, methane rain, and impact cratering) without invoking internal factors? Or Lopes, who was seeing ways to explain with one cause, volcanism, things that Moore would need to invoke a variety of causes for?

Titan as Mars Mars's orbit and inclination mean that the southern hemisphere's summer is shorter and hotter than summer in the north. As a result there's a net transfer of volatiles -- water -- from one end of the planet to the other. Saturn's orbit means that something similar applies to Titan, and Oded Aharonson of CalTech has a nice story to tell about how that, too, could lead to a net transfer of volatiles -- in this case, methane.

Continue reading "AGU: Three from Titan" »

Posted by Oliver Morton at 06:25 PM | Permalink

It makes me sad that my fine colleagues and rivals at Science magazine already beat me to this story, but it is too much fun not to note here. There's a poster here at AGU in which seismologists report detecting 'footquakes' - the sound of jubilant soccer fans (football to you British types) celebrating goals during a major competition.

Garrett Euler, of Washington University in St. Louis and colleagues, were initially puzzled by instaneous tremors that appeared to happen all over Cameroon one day soon after the researchers installed new seismic equipment. But finally one of them figured out it was the stomping of joyous fans across the country, each time the Cameroon team scored a goal in the African Cup of Nations. And the stomping got worse the longer the match went on. "Goals that came later in the match - when the tensions were near boiling point - caused substantially larger tremors," they write.

For the full story, go to page 13 of the IRIS seismology newsletter found here.

Posted by Alex Witze at 06:44 PM | Permalink

Turns out that Jim Hansen, the outspoken NASA climatologist, didn’t attend John Marburger’s talk on Monday night, in which Marburger (who is President Bush’s science advisor), called accusations of censoring US climate scientists ‘ignorant’.

Hansen, who has long gone public with his thoughts about the problems of human-caused global warming, has said in the past that NASA public-affairs people censored his public speeches and media interviews to play down the risks of climate change. On Monday, Marburger charged that such accusations were baseless, saying that he personally had tracked down each claim and found it to be wanting. Marburger didn’t mention Hansen by name, but the subtext was clear to everyone in the audience.

Asked for his response today, Hansen simply pointed to a new book called Censoring Science: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming. (I haven’t read it and thus can’t recommend it, but here is a link so you can see at least what it looks like.) According to Hansen, it details a systematic effort to suppress climate scientists such as himself.

Asked if he had ever spoken to Marburger about the issue of censorship, Hansen said simply: “Not about this.”

Hansen isn't just confining his criticisms to US leadership, though. He's got a draft letter in the works to UK prime minister Gordon Brown and the German chancellor Angela Merkel, criticising the planned construction of coal-fired power plants in their countries.

Asked today why he was focusing on these leaders when China is constructing a coal-fired power plant at the rate of nearly one per week, Hansen said he feels that the developed world needs to take responsibility, as it has been the source of the majority of carbon dioxide emissions up until this point.

Posted by Alex Witze at 06:18 PM | Permalink

Susan Solomon, an atmospheric scientist and lead author on the 2007 IPCC report, had a handy hint for any future authors attending her lecture today on stratospheric ozone depletion and climate change:

Proofread your papers.

The famous 1974 Nature paper by Mario Molina and Sherwood Roland, describing how chlorofluorocarbon chemicals are the trigger for ozone destruction in the stratosphere, contains an embarrassing typo in its title - one that has endured for more than 20 years of citations.

Check it out here.

Posted by Alex Witze at 02:05 AM | Permalink | Comments (3) | TrackBacks (0)

News from the Arctic just continues to get worse. A fair number of presentations here have been dealing with the dire 2007 conditions for sea ice and the Greenland ice sheet.

First up, Greenland. Last summer, more ice melted atop Greenland than ever before measured, adding to a consistent downward trend of some 135 gigatons of ice disappearing per year. Marco Tedesco, of the Goddard Space Flight Center in Maryland, told the meeting that surface temperatures in Greenland were four to six degrees Celsius warmer than usual this summer, which helped accelerate melting, particularly at high latitudes.

The situation is even more precarious for sea ice. A couple of researchers here have been tossing around dates like 2012 or 2014 for estimates of when the Arctic might be completely ice-free in summer. While these sorts of numbers are pretty arm-waving at the moment (numbers like 2040 were previously considered to be aggressive), there’s little reason to think the situation will get better in the next couple of years. Mark Serreze, of the University of Colorado, spent a keynote lecture on Tuesday showing images of Arctic ice shrinking like a snowman left out too long in the sun. In September of this year, sea ice covered just 4.2 million square kilometers - by far the lowest record ever.

And the ice isn’t only shrinking in extent – it’s also thinning. Don Perovich, of a US army cold regions and research laboratory in New Hampshire, reported on a single but extraordinary ice buoy in the Beaufort Sea. In June the buoy measured sea ice at that location as 3.3 metres thick – “really a healthy piece of ice,” as he put it. But by the end of the summer, 70 centimetres had melted off the top – and 2.2 metres (yes, metres) off the bottom.

When you see those dramatic maps of the Arctic ice extent shrinking over time, don’t forget that it’s also thinning – a complicating factor that may just make things worse in summers to come.

Posted by Alex Witze at 01:58 AM | Permalink | Comments (28) | TrackBacks (0)

NASA Night is always a stressful evening at AGU. Researchers who depend on NASA funding pack into a lecture hall to hear the head of NASA science talk from on high about how dire the funding situation. Everyone usually ends up leaving the room complaining.

Things are a little different this year, though. The new chief of science at NASA is Alan Stern, who for many years was "one of you", as he put it -- a scientist struggling to fly new missions in an era of ever-uncertain NASA budgets. Fortified with a glass of chardonnay, he held forth from the other side of the podium at NASA Night with an approach that some call a refreshing change. (You can read a Q&A piece Nature did recently with Stern here - subscription required.)

The main thing to remember, Stern cautioned the crowd at AGU, is that blaming the budget is not cool. The science mission directorate at NASA gets $5.4 billion a year. That's on the scale of the entire National Science Foundation. It has 53 missions currently flying, and a host more are slated for launch in 2008, such as the GLAST gamma-ray telescope and the Lunar Reconnaissance Orbiter. In other words, NASA's space and earth science programs are the envy of the international research community.

But the big problem is cost overruns. This has been known for some time - projects such as the James Webb Space Telescope, the successor to the Hubble Space Telescope, balloon in cost annually. But Stern made it abundantly clear just how much cost overruns are hurting the science community. Over the past five years, overruns on NASA science missions have cost the agency $5.8 billion. Yes, that's more than a billion dollars a year. The biggest offenders are the James Webb scope, which ran over by $1.3 billion over the past five years, and the SOFIA airborne telescope, at $1.1 billion (and it isn't even flying yet, despite having been finished years ago).

As a result, NASA is going to focus ever more strongly on cost control. "Once you're selected to run a mission, we're going to hold your feet to the fire," says Stern. How he will do that isn't exactly clear, but in many cases it might mean descoping a mission -- taking off an instrument or two -- or placing it in a different, less risky, orbit.

Of course, even with the most stringent belt-tightening measures at NASA, the agency is still subject to the whims of Congress. If Congress goes into the same financial meltdown it did last year, and passes a 'continuing resolution' to keep the government operating at fiscal year 2006 levels, NASA will suffer. A long-term continuing resolution, says Stern, "would almost certainly mean mission cancellations".

Posted by Alex Witze at 05:38 PM | Permalink

What a difference a year makes. Last AGU meeting, the evening keynote lecture was by Al Gore. This AGU, Gore was in Oslo, having picked up his Nobel Peace Prize for his climate activism, on the same day President Bush's science advisor John Marburger was giving a lecture here on climate change.

Gore got a standing ovation from the AGU scientists. Marburger got a slew of hostile questions. He probably should have expected this, given the Bush administration's policies on climate change. And lines like "scientists have lost credibility in this debate" didn't help either.

Marburger spoke for about 45 minutes on US climate policy, reinforcing many of the same messages he's put out there before. Bush recognizes the significance of climate change, Marburger argues, and has been saying as much since June 2001. The US is doing plenty to move towards taking action, including hosting a summit of major emitters in September and adopting 'aspirational' goals to improve energy consumption and develop new technologies to deal with it. Too much emphasis is being placed on mitigiation strategies for reducing carbon emissions, instead of adaptation strategies to get people to live differently in a greenhouse world.

Such messages did not go down well with the audience. Questioners pressed Marburger on mandatory emissions caps for US industries (ask Congress, says Marburger); alleged censorship of climate scientists (not a word of truth in it, he argues); and Bush's refusal to move the Kyoto protocol forward (Congress would have stymied it anyway).

Marburger also included a plea for people to read the details of the IPCC technical reports issued this year, not just the policymakers' summaries. Only in the technical reports, he argues, are the details and the complexity that everyone needs to understand in order to make informed decisions about what to do about climate change.

No one's arguing with that. But surely he hadn't forgotten that his very audience was made up of many of those who wrote the IPCC technical reports in the first place -- and they still don't agree with him.

Posted by Alex Witze at 05:19 PM | Permalink

Those Mars rovers just keep on trucking. It's been nearly four years since Spirit and Opportunity touched down separately on opposite sides of the red planet, but they're both still going strong. Steve Squyres of Cornell and John Callas of NASA provided an update here on how they're doing - and how they're still making surprising discoveries.

First to Spirit, which has been something of the underdog of the rovers. But finally, scientifically, "it's caught up to Opportunity," said Squyres. And it's all because of a problem mission managers have been cursing for some time: the fact that Spirit's right front wheel is stuck, and whenever they have to move the six-wheeled vehicle they have to drag the stuck wheel behind it like a recalcitrant shopping cart.

But this awkward movement means that there's a deep trench behind the rover wherever it moves. And that recently revealed a glistening white trail in the wheel trench. Chemical analyses show that the stuff is nearly entirely made of silica -- the stuff that makes up glass -- with a touch of titanium. And that, says Squyres, suggests two possible environments: either hot springs or volcanic fumaroles, both of which mean heat plus water -- and potentially life. It's the first time Spirit has found potentially habitable environments, the kind of warm watery places where microorganisms like to thrive.

Continue reading "AGU: The latest from Mars" »

Posted by Alex Witze at 04:27 PM | Permalink

...it's 4:15 pm, and the exhibit hall, where the posters are displayed, are already smelling of beer.

Posted by Alex Witze at 03:39 PM | Permalink

Join Nature at the American Geophysical Union meeting in San Francisco. Our reporters will be posting diary reports here from Monday 10 December, with all the latest news on the Earth, the ocean, and beyond to the stars.

Posted by Nicola Jones at 11:49 AM | Permalink | Comments (2) | TrackBacks (0)

The spring AGU meeting this year is in Acapulco, Mexico.. It is a joint affair with nearly a dozen Latin American societies. About 2,300 scientists have registered. This makes it smaller than some of the earlier joint meetings the AGU has held in the last four years to enhance scientific outreach. Certainly not as huge as the joint meeting with European societies four years ago in Nice, France, where some 10,000 scientists attended. Security at that event was insane, due to invasion/war in Iraq. No such problems in Acapulco. Although Mexican police/army trucks cruising oceanfront boulevard watching for drug lords are almost as frequent as buses. My long walk along the coast late last night turned up nothing but great pork posole and fine cazadores tequila. To many US-named fast-food spots along the way though. But at least a trendy little tequilaria like a coffee stand. Balmy doesn´t fully describe weather. Only a 2 degrees F spread predicted, from 82 to 84, day and nite. High humidity, full clouds. It´s Chabuso (read tropical storm) season. Hopefully, that doesn´t mean an earthquake. We sit atop one of THE most active quake zones. And new research revealed at the meeting raises the spector of a strange calm before a tectonic storm. Off to 14th floor hotel room. Hoping the building engineers did their job right decades ago when with this slightly frayed resort sprouted high-rises.

Posted by Nicola Jones at 11:07 PM | Permalink

Join Rex Dalton at the American Geophysical Union meeting in Acapulco from 22-25 May. He'll be blogging here for Nature.

Posted by Nicola Jones at 06:07 PM | Permalink

Well, Al Gore has been here and gone. He spoke for an hour to a packed ballroom, and crowds also filled overflow rooms to watch a closed-circuit broadcast of his talk.

He started out with many of the same stories he trots out in his movie, An Inconvenient Truth, and in the talks he's been giving on climate change around the country. Yes, he introduced himself as the man who used to be the next president of the United States. Yes, the audience laughed dutifully.

But he also tested the waters on a new topic - the loss of reason as a driving force in America. There are reports he will have a book out early next year, The Assault on Reason.

Here's Gore: "I’ve come to believe that the reason why knowledge, and science as the most refined category in the field of knowledge, seems now to be paying a less important role than it did in the past has to do with a fairly dramatic change in the ways in which we communicate information among ourselves....The meritocracy of ideas has virtually disappeared in the television space....As a result the role of knowledge and reason and logic has been diminished."

Gore called on the assembled scientists to engage with the public, to clearly communicate the results of their science - particularly any findings having to do with climate change: "When you come into possession of a truth that has deep implications for the future, and find courage to express it … you will find that the force of that truth will move obstacles from your path."

No, we don't know if he's running for president in 2008. Yes, he got a standing ovation - and signed autographs before slipping out of the ballroom.

Posted by Alex Witze at 01:08 AM | Permalink | Comments (2) | TrackBacks (0)

Sometimes a couple of scientific instruments, in just the right place, can trigger all sorts of new investigations. Take the three strainmeters that the Carnegie Institution of Washington placed along the eastern coast of Taiwan starting in 2003. Alan Linde and Selwyn Sacks, working with their Taiwanese colleagues, were trying to figure out why the area didn't seem to have as many large earthquakes as it should - being located on the boundary of two tectonics plates and all.

Instead, the scientists arrived at a whole new theory. Typhoons passing over the island, the team argues, release pressure on the land and allows the faults there to slip at very high, but very slow and non-dangerous, rates. In essence, tropical storms enable a lot of very small earthquakes and prevent the large and dangerous ones.

It's a very cool concept that, unfortunately, may not apply other areas of the world. The US Gulf Coast, for instance, is not at high risk of killer earthquakes and thus could conceivably be saved by hurricanes. But Japanese scientists are interested in extending the work to their country, Sacks told me at his poster session this morning.

"This is a big surprise for us," he said. "It's the kind of finding that is driven by data, not by insight."

Posted by Alex Witze at 12:53 AM | Permalink | Comments (3) | TrackBacks (0)

The big buzz for today is Al Gore's scheduled 12:30 talk on climate science and policy-making. Unfortunately, he won't be taking any questions, either from the audience or from reporters. But it should be interesting to hear what he has to say.

His movie An Inconvenient Truth is of course now out on DVD - and he's challenging the public to host a wave of viewing parties, with the first this Saturday. What do you think - is he gearing up for another presidential run in 2008? Is climate an issue that American voters care about? If not, should they?

Posted by Alex Witze at 05:45 PM | Permalink | Comments (1) | TrackBacks (0)

Some other people are also blogging this conference. Check them out:

-Andrew Alden, of About.com

- Joshua Colwell, with some good planetary science updates

- Kevin Vranes, who promises a good climate posting shortly

- Google Earth Blog, reporting on the 'virtual globes' sessions here

- Someone over at LiveJournal, with a focus on the traditional conference activities of drinking and hooking up

Gavin Schmidt of RealClimate will be talking about blogging and the global warming debate on Friday - unfortunately, I'll be gone.

And a thanks to Charlie Petit of the Knight Science Journalism Tracker, who thrilled me by linking to my blog ... although it seems to have since vanished off his page. Hmm. Anyway, Charlie - a longtime science journalist, formerly of the San Francisco Chronicle and US News and World Report - does a fantastic job of rounding up science journalism coverage every day, with his indomitable commentary on who's doing the best job around. Check it out.

Posted by Alex Witze at 05:32 PM | Permalink | Comments (3) | TrackBacks (0)

Those Mars rovers, Spirit and Opportunity, just keep rovin' along.

We science journalists have written that story time after time. The darn things just don't die. For the third consecutive year, project scientists presented their findings at a packed AGU press briefing.

Life for the twin rovers is getting tougher. Spirit spent the entire Martian winter - April through December - hunkered down to try to save energy. Its right front wheel is jammed, and mission controllers have to drive the thing in reverse. The radioisotope-powered alpha proton x-ray spectrometer instrument has been through so many half lives now that it takes days to conduct analyses that used to take hours.

And yet, says project scientist Ray Arvidson, "it's still exciting to come into work every day." Then he turns to Steve Squyres, the rovers' lead scientist, a slight glint of desperation in his eye. "Right, Steve? Right??"

Posted by Alex Witze at 09:08 PM | Permalink

The GRACE satellites are really very cool. Imagine: You've got two trapezoidal-looking satellites, chasing each other constantly above Earth's poles. They're about 130 miles apart from each other, but can measure their precise separation down to the precision of a single micron. GRACE is all about gravitational anomalies; big masses that shift around on Earth's surface exhibit subtle pulls on the satellites. And slight changes in distance between the two reveal how the masses are moving down below.

Those masses include water. Water is heavy, Jay Famiglietti of the University of California, Irvine, told the meeting today. Since its 2002 launch, GRACE has watched monsoon rains pile up in some regions of the world, like the MIssissippi river basin, and dry out in others, such as the Congo basin.

Water shifting around, as seen from space - that's just cool. Nature subscribers can read more in a News & Views article published here.

Posted by Alex Witze at 12:08 AM | Permalink

There are mountains on Saturn's moon Titan! Big ones! This newsblog won't let me post images, so check out the very cool pix here.

Posted by Alex Witze at 12:07 AM | Permalink

Lots of well-meaning scientists invade Capitol Hill every year, meeting with lawmakers and (usually) arguing for more money for their disciplines. David Goldston, chief of staff for the House Science Committee, had some tips today for how researchers could best survive Washington. He's worked on the Hill for 20 years, so this man knows what he's talking about. Call them Goldston's Top Tips:

1. Don't claim that science provides an easy answer to questions of policy. Establishing the relationship between greenhouse gas emissions and temperature rise is something scientists can and should do. Telling politicians how to regulate emissions is not.

2. Be very clear about the levels of uncertainty in your scientific field. In other words, don't try to sound like you know more than you do.

3. Do your homework. Realize the issues that are facing Congress every day, and that your inevitable plea for science funding will be balanced against competing priorities - say, the Iraq war or health care for children.

4. Remember Tip O'Neill's adage that all politics is local. Get to know your Congressional representatives at home, on their home turf. They'll listen to you better there than in Washington.

It'll be interesting to see how many of the geophysicists in the room will take all four to heart in January, when the new Congress convenes.

Posted by Alex Witze at 12:00 AM | Permalink

Peter Gleick, a water expert at the Pacific Institute in California, took issue this morning with the issue of consensus in science. His advice on how to deal with politicians and the public:

Don't say: 'Climate change is a big problem because most climate scientists agree it is a big problem.'

Say instead: 'Most climate scientists think climate change is a big problem because the best science available has convinced them it's a problem.'

It's a subtle argument, but a good one that is often lost in the public and political hoopla about what to do over climate change. Yes, consensus in science is a good thing to know about -- but just saying a lot of scientists believe in Position X doesn't make Position X right.

Posted by Alex Witze at 11:56 PM | Permalink | Comments (1) | TrackBacks (0)

Hurricane researchers have a new idea: Get the oil industry to help pay for research into better forecasting the approach and impact of hurricanes.

After the devastating 2005 hurricane season, scientists scrambled for new ways to better improve hurricane science - in particular, forecasts of hurricane intensity, which lag far behind forecasts of hurricane trajectories. Greg Holland, of the National Center for Atmospheric Research, described the result today: the Hurricane Intensity Forecast Improvements and Impact Projections, or HiFi.

It's a research push estimated to cost $250 million over ten years. Project leaders plan to hit up oil industry, who maintain their own hurricane information in a patchwork fashion - wind meters on their offshore oil platforms, and the like - but who have yet to share that information with the rest of the community.

It's a good idea. One can only hope the money is forthcoming, and a decade from now we will never see the likes of Katrina again.

Posted by Alex Witze at 06:04 AM | Permalink

First up on my slate this morning was a session on paleoclimate temperature reconstructions for the past millennium. This, of course, involves the famous 'hockey stick' reconstruction showing that temperatures in the 20th century were unequalled in the past 1,000 years. That, of course, is according to paleoclimatologist Michael Mann, his coauthors, and a National Academy of Sciences study that broadly reaffirmed their findings earlier this year.

It's always fun to be in the same room with Mann and his chief antagonist, Steve McIntyre. McIntyre, a mineral exploration consultant from Canada, has spent years working to debunk Mann's hockey stick graph and its implications. Earlier this year, both spent an afternoon at the NAS presenting their respective sides of the argument to the panel of assembled experts. Mann left the room without giving McIntyre so much as a glance.

Sadly, there were no new fireworks today. Mann spent much of McIntyre's talk looking down at his lap and shaking his head. And McIntyre sat back down after his talk without even arguing with the other critics in the audience. Could it be finally true? Has the community actually moved on? Will we ever have to hear about hockey sticks ever again?

Posted by Alex Witze at 02:24 AM | Permalink | Comments (1) | TrackBacks (0)

There's one word for this meeting: packed.

I've been coming to AGU for more than a decade, and there are more people here than ever. There are more than 13,500 abstracts and 1,100 oral sessions. The numbers of presentations, and attendees, keep going up. Today, the registration line snaked around the lobby of the Moscone Center in San Francisco and back on itself. Several times.

I sure hope not everybody shows up on Thursday noon to hear Al Gore speak - we'll never all get in.

Posted by Alex Witze at 02:22 AM | Permalink

Join Alex Witze as she blogs from the AGU meeting in San Francisco, Dec 11-15.

The homepage of her blog is here.

Posted by Nicola Jones at 10:29 AM | Permalink