Earth Institute at the American Geophysical Union


Earth Institute scientists are presenting scores of talks at the world’s largest gathering of earth scientists, the fall 2008 meeting of the American Geophysical Union. Subjects include unseen natural hazards, changing climate, and how mankind will deal with these challenges. Most researchers at AGU come from two of the Earth Institute’s largest centers: Lamont-Doherty Earth Observatory, and Goddard Institute for Space Studies. AGU is held Dec. 15-19, 2008, in San Francisco. Below, highlights.  (Note: not all listings are in chronological order.)

Threat to the Planet: Dark and Bright Sides of Global Warming

James E. Hansen, director
Hansen, one of the strongest and most consistent scientific voices on global warming, says we are approaching a “tipping point” into rapid, catastrophic climate changes. The bright side: if we act now to reduce greenhouse gases, we may avert not only the negative effects, but get cleaner air and water, improved human health and greater agricultural productivity. Unfortunately, says Hansen, the policies of even the “greenest” nations so far are impotent, and energy companies and reactionary governments have subverted democratic processes. Without change, public protests will grow—and young people and the unborn will pay the price.
Wednesday, Dec. 17, 1:40 pm. Room 3008. Session A33D

Secrets of the East Pacific Rise

John Mutter; Suzanne Carbotte
The newly launched Marcus G. Langseth, run by Lamont for the National Science Foundation, is the world’s most advanced academic seismic vessel. This summer it produced the most detailed 3D pictures of a midocean ridge yet, and carried out many other investigations over the East Pacific Rise, some 500 miles off Mexico. Researchers observed deep hydrothermal circulation, earthquakes, magma bodies and other hidden phenomena. They present initial findings.
Tuesday, Dec. 16, 8:00am-12pm. Hall D. Poster Session B21A
Related: Suzanne Carbotte gives the Birch Lecture, “Focusing in on Mid-Ocean Ridge Segmentation.” Wed. Dec. 17, 5pm.  Room 3008. Session T34B

Implications of ‘Peak Oil’ for CO2 and Climate

Pushker Kharecha
Much of the alarm about climate change focuses on burning of oil and gas; but Kharecha says the real key to keeping atmospheric CO2 below dangerous levels lies in eliminating emissions from coal. Projected declines in gas and oil reserves means their future emissions will be limited—but there is plenty of coal left, and its use is growing. Kharecha says eliminating coal emissions by 2030 by trapping gases or switching to sustainable energy sources would make CO2 manageable. Kharecha appears at a Wednesday press conference on Peak Oil; his full talk is Thursday.
PRESS CONFERENCE: Wednesday, Dec. 17, 9:00am, Room 3015
TALK: Thursday, Dec. 18, 10:20am. Room 3016. Session U42A
Further info:

Ancient Trees, Ancient Cultures, Abrupt Climate Change

Edward Cook, Kevin Anchukaitis and others
Lamont’s Tree Ring Lab is unraveling the workings of the Asian monsoon, including the causes of sudden, devastating droughts. Searches across southeast Asia have revealed trees whose rings record temperature and precipitation for 1,000 years. They show droughts in the 15th, 17th and 18th centuries, concurrent with big human shifts, including the fall of Cambodia’s Angkor Wat culture. Separate poster and talk, plus press conference on abrupt climate change.
POSTER: Tuesday, Dec. 16, 8:00am-12pm. Hall D. Poster PP21A-1403
PRESS CONFERENCE: Tuesday, Dec. 16. Room 3015
TALK: Tuesday, Dec. 16, 4:30pm. Room 3001. Session PP24A (Invited)

Harnessing Rocks to Soak Up CO2

Peter Kelemen and Juerg Matter
Kelemen and Matter work in the deserts of Oman, and say that peridotite, the dominant rock there, could be harnessed to absorb vast amounts of globe-warming CO2, and lock it underground. Peridotite is normally found in the mantle, but here, it pokes though the surface. The scientists say it reacts naturally with CO2 to produce solid minerals on a scale previously unsuspected—and that the process could be speeded a million times by simple drilling and injection of CO2-rich liquids. They think Oman alone might store more than 10% of annual human carbon output—and similar formations are spread from the Adriatic to the south Pacific. They hope to start a pilot project soon.
Monday, Dec. 15, 9:15am, Room 2002. Session H11J
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Melting in the Antarctic?

Richard Cullather; Stan Jacobs
Antarctic coastal waters are becoming less salty—an indication that more fresh water is entering. The authors say the evidence points to increasing attrition of continental ice, and fast-moving changes in the extent, movement and thickness of sea ice, as climate shifts.
Monday, Dec. 15, 10:50am. Room 2020. Session OS12A

The New York City Climate Change Adaptation Task Force

Cynthia Rosenzweig
New York has started one of the world’s first, and most comprehensive, efforts to assess and deal with climate change. Advised by a panel of scientists, the city’s task force seeks to predict and adapt to the effects of rising sea level, higher temperatures and extreme weather events. Water supplies, roads, subways, sewers and health systems are all part of the picture. Part of a larger session on regional adaptation.
Monday, Dec. 15, 11:20am. Room 2004. Session PA 12A
Further info:

Bangladesh’s Weak Underbelly

Scott Nooner  snooner@ldeo.columbia.eduMichael Steckler; S. Chowdhury
With the immense discharge of the Ganges-Brahmaputra delta, a third or more of Bangladesh is flooded during monsoon season. The authors say that the waters weigh so much, and the sediments composing the region are so weak, the land surface is depressed as much as 6 centimeters, as measured by satellite and GPS instruments. Only the Amazon sees more water movement—but it does not sink nearly as much. Bangladesh’s apparently weak underbelly may not only help spread flooding; it could heighten earthquake risk.
Monday, Dec. 15, 1:40pm-5:30pm. Hall D. Poster session T13B-1958

Short-Term Pollutants Are Driving Rapid Arctic Change

Climate Change and Shifting Rains

Wallace Broecker
Broecker, a seminal figure in climate studies, earlier showed how oceans can interact powerfully with atmosphere. Now he is thinking about hydrology: how warming climate might pour rain onto the tropics, but make higher-latitude drylands ever more parched. The human consequences could be drastic. He says records from glacial times bear out the hypothesis.
Tuesday, Dec. 16, 11:40am. Moscone Room 3016. Session U22A (Invited)

Drew Shindell
Airborne pollutants may travel great distances from inhabited regions to the arctic, and these are contributing significantly to the outsize warming and melting trends seen there. These short-lived but powerful substances include methane, low-altitude ozone and heat-absorbing soot. Shindell says emissions must be reduced.
Tuesday, Dec. 16, 4:35pm.  Room 3016. Session U24B

New York Tsunami: Did It Come From Space?

Dallas Abbott; Frank Nitsche; and others
Evidence is building that a great tsunami hit the New York City area some 2,300 years ago. The story is told in a layer of disturbed sediment up to half-meter thick, stretching from New Jersey into the Hudson River estuary. It holds spherules and shocked rock fragments characteristic of a comet or meteorite impact—possibly the tsunami’s cause. Given the huge population here now, it is important to understand this event. Two poster sessions.
Wednesday, Dec. 17, 8:00am-12:14pm. Poster P31A-1381
Friday, Dec. 19, 1:40-5:30pm. Hall D. Poster OS53B-1311

How We Helped Make the 1930s Dust Bowl

Ben Cook
Natural temperature changes over the Pacific cause periodic droughts over southwestern North America. In the 1930s, poor farming practices amplified this natural event into the disastrous Dust Bowl, says Cook. Farmers replaced drought-resistant prairie grasses with fragile wheat, and allowed livestock to overgraze pastures. When drought came, ever more dust rose into the air; this in turn caused rainfall to drop even further, and moved the drought northward into the breadbasket regions of the Great Plains. Similar practices are now common in drought-vulnerable places including China. 
Thursday, 8am-12pm. Hall D. Poster B41B-0374
Further info:

Virtual Ocean, and Other New Ways to Roam the Planet

William Ryan
Like Google Earth does on land, Virtual Ocean, a new 3D rotatable globe, now takes you below the oceans. One can zoom from planetary scale down to seafloor topography, earthquake data, sediment layers and even photos of living things and other small features. Still being refined, it is already being used by researchers, school teachers and the general public. Two sessions.
Thursday, Dec. 18, 1:40-5:30pm. Hall D, Poster session IN43A
Friday, Dec. 19, 11:20am. Room 3008. Session ED52A
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Where the Carbon Hits the Water

Samar Khatiwala
The oceans absorb an estimated fifth to third of human-produced CO2, making them pivotal in climate; yet, we are still quite uncertain about the distribution and rate of uptake. Khatiwala has made the first observationally-based 3-dimensional reconstruction spanning industrial times. He confirms, as many suspect, that the Southern Ocean is the primary conduit—some 40% of the manmade carbon now in the oceans--but says its role has shifted significantly.
Thursday, Dec. 18, 1:55pm.  Room 3016. Session U43D

Earthquake Ruptures: How Deep, How Dangerous?

Bruce Shaw
It is conventional wisdom that earthquake faults do not go much deeper than the depths at which we detect seismic waves from slippage. However: recent work suggests that large faults could silently propagate much deeper. If this is true, it bears on our basic understanding of earthquake mechanics—and could affect hazard estimates where large quakes are a danger.
Friday, Dec. 19, 8:00am. Room 3005. Session T51D. (Invited)