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New NOAA report examines national oil pollution threat from shipwrecks

Report presented to U.S. Coast Guard for use in contingency plans

Disabled T/B DBL 152 vessel discharges oil into the Gulf of Mexico in 2005. Credit: ENTRIX, Inc.

NOAA presented to the U.S. Coast Guard today a new report that finds that 36 sunken vessels scattered across the U.S. seafloor could pose an oil pollution threat to the nation’s coastal marine resources. Of those, 17 were recommended for further assessment and potential removal of both fuel oil and oil cargo.

The sunken vessels are a legacy of more than a century of U.S. commerce and warfare. They include a barge lost in rough seas in 1936; two motor-powered ships that sank in separate collisions in 1947 and 1952; and a tanker that exploded and sank in 1984. The remaining sites are 13 merchant marine ships lost during World War II, primarily along the Atlantic Seaboard and Gulf of Mexico. To see a list of the ships and their locations, visit this page.

The report, part of NOAA’s Remediation of Underwater Legacy Environmental Threats (RULET) project, identifies the location and nature of potential sources of oil pollution from sunken vessels. Knowing where these vessels are helps oil response planning efforts and may help in the investigation of reported mystery spills--sightings of oil where a source is not immediately known or suspected.

“This report is the most comprehensive assessment to date of the potential oil pollution threats from shipwrecks in U.S. waters,” said Lisa Symons, resource protection coordinator for NOAA’s Office of National Marine Sanctuaries. “Now that we have analyzed this data, the Coast Guard will be able to evaluate NOAA’s recommendations and determine the most appropriate response to potential threats.”

“The Coast Guard is pleased to receive these risk assessments from our partner agency NOAA and looks forward to our continued coordination on the matter of potential pollution associated with sunken vessels in U.S. waters,” said Capt. John Caplis, the Coast Guard’s chief of marine environmental response. “Coast Guard federal on-scene coordinators receiving the risk assessments will carefully review the data and incorporate it into their area contingency plans.”

In 2010, Congress appropriated $1 million for NOAA to develop a list of the most significant potentially polluting wrecks in U.S. waters, including the Great Lakes, specifically addressing ecological and socio-economic resources at risk. Those funds were not intended for oil or vessel removal.

NOAA maintains the internal Resources and UnderSea Threats (RUST) database of approximately 30,000 sites of sunken material, of which 20,000 are shipwrecks. The remaining items are munitions dumpsites, navigational obstructions, underwater archaeological sites, and other underwater resources.

Initial screening of these shipwrecks revealed 573 that could pose substantial pollution risks, based on the vessel’s age, type, and size. This includes vessels built after 1891, when U.S. vessels began using fuel oil; vessels built of steel; vessels over 1,000 gross tons, and any tank vessel.

Additional research about the circumstances of each vessel’s loss narrowed that number to 107 shipwrecks. Of those, some were deemed navigational hazards and demolished, and others were salvaged. Most of the 107 wrecks have not been directly surveyed for pollution potential, and in some cases little is known about their current condition.

To prioritize and determine which vessels are candidates for further evaluation, NOAA used a series of risk factors to assess the likelihood of substantial amounts of oil remaining onboard, and the potential ecological and environmental effects if that oil spills. Risk factors include the total oil volume onboard as cargo or fuel, the type of oil, and the nature of the sinking event. For example, a vessel that was struck by multiple torpedoes would likely contain less oil than a vessel that sank in bad weather.

After this third level of screening, 87 wrecks remained on the list developed for the Coast Guard’s area contingency plans. Among this group, NOAA determined that 36 shipwrecks are candidates for a “Worst Case” discharge event in which the shipwreck’s entire fuel oil and oil cargo would be released simultaneously, and recommended that 17 of these wrecks be considered for further assessment and feasibility of oil removal.

Six wrecks are potential candidates for a “Most Probable” discharge event, where a shipwreck could lose approximately 10 percent of its fuel oil or oil cargo. To date, known oil discharges from shipwrecks are typically in the “Most Probable” category or smaller.

The report, including 87 risk assessments, is not intended to direct Coast Guard activities, but rather provide the Coast Guard with NOAA’s scientific and technical assessment and guidance as a natural resource and cultural heritage trustee.

The Coast Guard, as the federal On-scene Coordinator for mitigating oil spills in the coastal marine environment, the Regional Response Teams, and local Area Committees, as established under the Oil Pollution Act of 1990, will review and incorporate the assessments into regional and area marine environmental response contingency plans. The individual risk assessments not only highlight concerns about potential ecological and socio-economic impacts, but also characterize most of the vessels as historically significant and many of them as grave sites, both civilian and military.

Funding for any assessment or recovery operations determined to be necessary is dependent upon the unique circumstances of the wreck. If a wreck still has an identifiable owner, that owner is responsible for the cost of cleanup. Coast Guard officials say that if no responsible party exists, the Oil Spill Liability Trust Fund would likely be accessed.

To view the report, 2012 Risk Assessment for Potentially Polluting Wrecks in U.S. Waters, visit this page.

As America’s maritime first responder, the Coast Guard protects those on the sea, protects our nation from threats delivered by sea, and protects the sea itself. By executing our marine environmental protection responsibilities, the Coast Guard reduces the risk of harm to the marine environment by developing and enforcing regulations to prevent and respond to maritime oil spills and hazardous substance releases.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources.

Former Secretary of State Hillary Rodham Clinton & Harrison Ford Lead Provocative Conversation on Conservation

Former Secretary of State Hillary Clinton and Harrison Ford on stage for Conservation International. Credit: Conservation International

Conservation International Board member Harrison Ford and former Secretary of State Hillary Rodham Clinton took the stage May 15 at Conservation International's 16th Annual New York Dinner to discuss the urgent need to preserve our natural capital. The conversation, which ranged from illegal wildlife trade in Africa to the effects of a changing climate on the Arctic, underscored the direct connection between conservation and our economic and security interests.

 

Sea level: One-third of its rise comes from melting mountain glaciers

The Aletschglacier in Switzerland is a typical valley glacier and the largest one in the Alps. Its volume loss since the middle of the 19th century is well visible from the trimlines to the right of the image. Credit: Frank Paul, UZH

How much all glaciers contribute to global sea-level rise has never been calculated before with this accuracy. An international group of researchers involving two geographers from the University of Zurich has confirmed that melting of glaciers caused about one third of the observed sea-level rise, while the ice sheets and thermal expansion of sea water account for one third each. So far, estimates on the contribution of glaciers have differed substantially. Now 16 scientists from nine countries have compared the data from traditional measurements on the ground with satellite data from the NASA missions ICESat (Ice, Cloud and land Elevation Satellite) and GRACE (Gravity Recovery and Climate Experiment).

Combined with a glacier inventory that is available globally for the first time, the researchers were able to determine the glacier mass changes all over the world much more accurately than before. «The extrapolations of local field measurements to large regions and entire mountain ranges traditionally applied sometimes overestimated the ice loss», describes UZH geographer Frank Paul the findings from the satellite measurements. And his fellow colleague Tobias Bolch adds: «We are well aware of the weaknesses of the individual satellite methods. However, in highly glacierized regions the results obtained using the two different methods agree well. With the mix of methods that have now been tested and applied, we have come a major step closer to determining glacier mass loss with higher precision.»

Meltwater pounded at surface in accumulation zone, Columbia Glacier, Alaska, July 2008. Credit: W. Tad Pfeffer

 

Earlier estimates should be corrected

The results show that almost all glacier regions lost mass in the years 2003 to 2009, most of all in Arctic Canada, Alaska, coastal Greenland, the southern Andes and in the Himalayas. By contrast, the glaciers in Antarctica – smaller ice masses that are not connected to the ice sheet – made scarcely any contribution to sea-level rise during this period. This finding deviates significantly from previous estimates, saying that the Antarctic glaciers caused around 30% of the global ice loss in the period from 1961 to 2004. «However, neither the periods nor the data basis are directly comparable here», adds Bolch, «so we shouldn't make any premature conclusions in this respect.»

The results published in «Science» have important consequences for past studies: Bolch and Paul conclude by recommending that «Earlier global estimates on the contribution of glaciers to sea-level rise should be revised again».

Citation: Alex S. Gardner, Geir Moholdt, J. Graham Cogley, Bert Wouters, Anthony A. Arendt, John Wahr, Etienne Bertier, Regine Hock, W. Tad Pfeffer, Georg Kaser, Stefan R. M. Ligtenberg, Tobias Bolch, Martin J. Sharp, Jon Ove Hagen, Michiel R. van den Broeke, Frank Paul. A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009. Science. May 17, 2013. Doi: 10.1126/science.1234532

The UZH geographers Tobias Bolch and Frank Paul contributed important basic data for the study: digital glacier outlines for the global glacier inventory from different regions in the world for which no precise data were previously available. For example for Alaska, Baffin Island, Greenland, the Alps, high-mountain Asia including the Himalayas as well as own calculations on the mass loss in Greenland and in high-mountain Asia.

Contact: Tobias Bolch
tobias.bolch@geo.uzh.ch
41-446-355-236
University of Zurich

Study reveals scientific consensus on anthropogenic climate change

A comprehensive analysis of peer-reviewed articles on the topic of global warming and climate change has revealed an overwhelming consensus among scientists that recent warming is human-caused.

The study is the most comprehensive yet and identified 4000 summaries, otherwise known as abstracts, from papers published in the past 21 years that stated a position on the cause of recent global warming – 97 per cent of these endorsed the consensus that we are seeing man-made, or anthropogenic, global warming (AGW)

Led by John Cook at the University of Queensland, the study has been published today, Thursday 16 May, in IOP Publishing's journal Environmental Research Letters.

The study went one step further, asking the authors of these papers to rate their entire paper using the same criteria. Over 2000 papers were rated and among those that discussed the cause of recent global warming, 97 per cent endorsed the consensus that it is caused by humans.

The findings are in stark contrast to the public's position on global warming; a 2012 poll* revealed that more than half of Americans either disagree, or are unaware, that scientists overwhelmingly agree that the Earth is warming because of human activity.

John Cook said: "Our findings prove that there is a strong scientific agreement about the cause of climate change, despite public perceptions to the contrary.

"There is a gaping chasm between the actual consensus and the public perception. It's staggering given the evidence for consensus that less than half of the general public think scientists agree that humans are causing global warming.

"This is significant because when people understand that scientists agree on global warming, they're more likely to support policies that take action on it."

In March 2012, the researchers used the ISI Web of Science database to search for peer-reviewed academic articles published between 1991 and 2011 using two topic searches: "global warming" and "global climate change".

After limiting the selection to peer-reviewed climate science, the study considered 11 994 papers written by 29 083 authors in 1980 different scientific journals.

The abstracts from these papers were randomly distributed between a team of 24 volunteers recruited through the "myth-busting" website skepticalscience.com, who used set criteria to determine the level to which the abstracts endorsed that humans are the primary cause of global warming. Each abstract was analyzed by two independent, anonymous raters.

From the 11 994 papers, 32.6 per cent endorsed AGW, 66.4 per cent stated no position on AGW, 0.7 per cent rejected AGW and in 0.3 per cent of papers, the authors said the cause of global warming was uncertain.

Co-author of the study Mark Richardson, from the University of Reading, said: "We want our scientists to answer questions for us, and there are lots of exciting questions in climate science. One of them is: are we causing global warming? We found over 4000 studies written by 10 000 scientists that stated a position on this, and 97 per cent said that recent warming is mostly man made."

Visitors to the skepticalscience.com website also raised the funds required to allow the study to be accessible to the public.

Daniel Kammen, editor-in-chief of the journal Environmental Research Letters, said: ""This paper demonstrates the power of the Environmental Research Letters open access model of operation in that authors working to advance our knowledge of climate science and to engage in a public discourse can guarantee all interested parties have the opportunity to review the same data and findings."

Citation: 'Quantifying the consensus on anthropogenic global warming in the scientific literature' John Cook, Dana Nuccitelli, Sarah A Green, Mark Richardson, Bärbel Winkler, Rob Painting, Robert Way, Peter Jacobs and Andrew Skuce 2013 Environ. Res. Lett. 8 024024. doi:10.1088/1748-9326/8/2/024024

Contact: Michael Bishop
michael.bishop@iop.org
01-179-301-032
Institute of Physics

Fall warming on Antarctic Peninsula driven by tropically forced circulation

The German research vessel, Polarstern, is shown off the Rothera station on the west coast of the Antarctic Peninsula. Rothera is one of eight stations that provided temperature data for this research. Credit: Hannes Grobe/Alfred Wegener Institute for Polar and Marine Research

The eastern side of the Antarctic Peninsula, a finger of the southern polar continent that juts toward South America, has experienced summer warming of perhaps a half-degree per decade – a greater rate than possibly anywhere else on Earth – in the last 50 years, and that warming is largely attributed to human causes.

But new University of Washington research shows that the Southern Hemisphere's fall months – March, April and May – are the only time when there has been extensive warming over the entire peninsula, and that is largely governed by atmospheric circulation patterns originating in the tropics.

The autumn warming also brings a notable reduction in sea ice cover in the Bellingshausen Sea off the peninsula's west coast, and more open water leads to warmer temperatures on nearby land in winter and spring (June through November), said Qinghua Ding, a UW research associate in Earth and space sciences. In fact, the most significant warming on the west side of the peninsula in recent decades has occurred during the winter.

"Local northerly wind pushes warmer air from midlatitudes of the Southern Ocean to the peninsula, and the northern wind favors warming of the land and sea ice reduction," said Ding.

He is the lead author of a paper explaining the findings, published online this month in the Journal of Climate. Eric Steig, a UW professor of Earth and space sciences, is co-author. The work was funded by the National Science Foundation.

The scientists analyzed temperature data gathered from 1979 through 2009 at eight stations on the Antarctic Peninsula. The stations were selected because each has reliable monthly data for at least 95 percent of the study period. They also used two different sets of data, one from Europe and the other from NASA, that combine surface observations, satellite temperature data and modeling.

The Antarctic Peninsula (in box) extends northward from the main part of the continent toward South America. Credit: CIA World Factbook

The researchers concluded that the nonsummer Antarctic Peninsula warming is being driven by large-scale atmospheric circulation originating in the equatorial Pacific Ocean. There, the warm sea surface generates an atmospheric phenomenon called a Rossby wave train, which reaches the Antarctic Peninsula and alters the local circulation to warm the region.

The sea-surface temperature trend in the tropical Pacific is related to natural phenomena such as the El Niño Southern Oscillation (El Niño and La Niña) and cycles that occur on longer timescales, sometimes decades. But it is not clear whether human causes play a role in that trend.

"We still lack a very clear understanding of the tropical natural variability, of what that dynamic is," Ding said.

He said that in the next two or three decades it is quite possible that natural variability and forcing from human factors will play equivalent roles in temperature changes on the Antarctic Peninsula, but after that the forcing from human causes will likely play a larger role.

"If these trends continue, we will continue to see warming in the peninsular region, there is no doubt," Ding said.

Reference: Temperature change on the Antarctic Peninsula linked to the tropical Pacific
Qinghua Ding and Eric J. Steig.Journal of Climate 2013 ; doi: http://dx.doi.org/10.1175/JCLI-D-12-00729.1

Contact: Vince Stricherz
vinces@uw.edu
206-543-2580
University of Washington

UCLA study shows warming in central China greater than most climate models indicated

China's Loess Plateau. Credit: Gaojun Li

Temperatures in central China are 10 to 14 degrees Fahrenheit hotter today than they were 20,000 years ago, during the last ice age, UCLA researchers report — an increase two to four times greater than many scientists previously thought.

The findings, published today in the early online edition of the journal Proceedings of the National Academy of Sciences, could help researchers develop more accurate models of past climate change and better predict such changes in the future.

"Previously, we could only infer temperature on land through changes in climate archives like tree rings or pollen over time," said lead author Robert Eagle, a UCLA researcher in the department of Earth and space sciences. "This is the first time that temperature has been determined accurately on land at the time of the last ice age."

To make their temperature measurements, the scientists used a technique known as clumped isotope thermometry, which detects subtle atomic differences in calcium carbonate, a compound commonly found in rocks, snail shells and wind-blown dust deposits known as loess. The method is the most accurate land-based temperature-determination tool available today.

"We can now tell what temperatures were on land 20,000 years ago with more accuracy than was ever previously possible," said senior author Aradhna Tripati, a UCLA assistant professor in the department of Earth and space sciences and the department of atmospheric and oceanic sciences.

Tripati and Eagle chose to study the Loess Plateau in central China, a 250,000-square-mile agricultural region some 500 miles southwest of Beijing, because of its wide expanses of loess, the silty sediments that give the area its name and which contain deposits from the last ice age.

"We can calculate temperatures and reconstruct the chemistry of rainwater from the past ice age, then compare this to the present day climate in specific regions," Eagle said. "We can then use this information to validate current climate models and study atmospheric processes."

The researchers collected two unique ice age sample types from the Loess Plateau region: fossilized land-snail shells and soil deposits. While snails calcify quickly over just a few years, soil carbonates grow over longer time periods, ranging from a few hundred to thousands of years. Eagle and Tripati used clumped isotope thermometry to determine the temperature at which these samples formed roughly 20,000 years ago.

"One of the most important aspects of the study was showing that we could get the same result from such different types of carbonates," said Tripati, who is also a member of UCLA's Institute of the Environment and Sustainability. "Even though these materials integrate over very different time frames, they gave us the same result."

Comparing the findings with climate models

When Eagle and Tripati matched their findings against climate models predicting the change in temperature in central China from the previous ice age to the present, they found that those models that took into account atmospheric processes tended to be more accurate.

"The climate models that did the best job of resolving temperature changes in this region were the ones that accurately depicted very large-scale atmospheric processes, such as patterns of winds in the atmosphere, the position of the jet stream and various atmospheric fronts," Tripati said. "The models that didn't resolve these atmospheric phenomena tended to do a poorer job of predicting temperature.

"It's so important to have models that accurately depict regional climates on land for the study of past and future climate change. We were surprised at how poorly most climate models predicted temperature change in central China and also surprised at how sensitive this region has been to changes in climate forcing."

Since the last ice age, numerous factors have influenced changes in global wind and precipitation patterns in Earth's atmosphere. Atmospheric processes move in relation to a standing, stationary wave, which is an oscillating reference point that wraps around our planet like an invisible piece of string. The position of that wave around our planet has changed over time. Contributing factors have been a rise in carbon dioxide and other greenhouse gases, changes in incoming solar radiation and changes in the amount of ice covering the Earth's surface.

For example, ice sheets can deflect the stationary waves so that winds and precipitation patterns fall more frequently in certain locations on the planet. But as ice has melted over the last 20,000 years, the stationary waves have shifted, influencing the circulation of the atmosphere.

"Clumped isotope thermometry has allowed us to say with more confidence how temperatures have warmed in central China, and how the chemistry of rainfall has changed. The climate models that did the best job of simulating temperature changes seemed to also be the ones to give the best depiction of changes in water cycling in this region," Tripati said. "Our results suggest that in this region, temperature, water cycling and winds are very sensitive to changing climate forcing. Rises in greenhouse gas levels, melting ice sheets and changes in solar radiation can all affect not only temperature but precipitation and winds as well."

"We have not dissected out the specific role of greenhouse gases, such as carbon dioxide, in this study, but they are certainly a contributing factor to temperature change and ice-sheet extent," Eagle said.

The climate model developed by researchers at France's Institut Pierre Simon Laplace des sciences de l'Environnement Global (the IPSL model) closely matched the data for this region in this study, but it has traditionally been one of the less frequently used climate models for predicting future climate change.

"That is quite extraordinary," said Eagle, "because while more commonly used models have simulated a very small amount of temperature change in the region, that prediction was not validated by our data."

Types of sediment similar to that found in central China exist in the Midwestern U.S., ranging from Mississippi to Nebraska, and they are currently being studied by scientists at UCLA.

"One of the things we're doing is measuring samples from the loess deposits in the Midwestern U.S. to see how climate has changed in these regions," Tripati said. "These deposits were also formed at the time of the last ice age and contain similar types of snail and soil carbonates that we analyzed in central China. It will be interesting to repeat a similar investigation in this region."

This research was funded by the National Science Foundation. Significant contributions to the research were made by Eagle and Tripati at UCLA; Gaojun Li, a faculty member at Nanjing University in China; UCLA collaborators Jonathan L. Mitchell, Ulrike Seibt and David Neelin; and Camille Risi, a research scientist at the Laboratory of Dynamic Meterology (LMD/IPSL) at the Center for National Scientific Research (CNRS) in Paris, France.

Contact: Stuart Wolpert
swolpert@support.ucla.edu
310-206-0511
University of California - Los Angeles

UCLA is California's largest university, with an enrollment of more than 40,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university's 11 professional schools feature renowned faculty and offer 337 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Six alumni and six faculty have been awarded the Nobel Prize.

Sulfate aerosols cool climate less than assumed

Life span of cloud-forming sulfate particles in the air is shorter than assumed due to a sulfur dioxide oxidation pathway which has been neglected in climate models so far

Measurement Station Schmücke: HCCT 2010 (Hill Cap Cloud Thuringia 2010). Credit: Dr. Stephan Mertes/TROPOS

In their role as condensation nuclei, aerosol particles are an important trigger for the formation of clouds. As humidity accumulates on the particles droplets are formed, which later develop into clouds. Within the clouds, however, the chemical composition of these aerosol particles changes.

In order to find out exactly what happens within the clouds, Eliza Harris and Bärbel Sinha from the Max Planck Institute for Chemistry, together with other scientists form Mainz and further research institutes, investigated different air parcels. The special feature of their experiments was that they investigated a cloud which formed on top of a mountain. The scientists could therefore trace how the aerosol particles changed while the cloud was forming.

Eliza Harris' main focus was the analysis of sulfur compounds. She investigated their composition in air samples which were collected at different times: Before the parcels entered the cloud, while they were in the cloud, and after they left the cloud.

The sulfur compounds in the samples differed in the distribution of sulfur isotopes. Isotopes are atoms of the same elements differing in the number of neutrons in the core and thus can be differentiated with the help of a mass spectrometer. The NanoSIMS ion microprobe, a highly sensitive mass spectrometer, enabled Harris to look into the chemical processes. "The relative reaction rates of isotopes are like fingerprints, which tell us how the sulfate was formed from the sulfur dioxide", Eliza Harris explains her method, which was part of her doctoral research in the group of Peter Hoppe at the Max Planck Institute for Chemistry.

Harris' measurements showed that sulfate in clouds forms mostly through the oxidation of sulfur dioxide (SO2) by oxygen (O2). This reaction is catalysed by so-called transition metal ions (TMI) like iron, manganese, titanium or chromium. In addition, sulfate production mostly occurred in cloud droplets which formed on large mineral dust particles, the most important source of transition metal ions. Much less often the trail led to the oxidation of SO2 by hydrogen peroxide (H2O2) and ozone (O3). "As my colleagues and I compared the basic assumptions of climate models with my results we were very surprised, because only one of twelve models considers the role of transition metal ions in the formation of sulfate", says the scientist, who is now working at the Massachusetts Institute of Technology (MIT) in the USA. Instead, most of the models used the alternative pathways of sulfur dioxide oxidation by hydrogen peroxide (H2O2), ozone (O3) and the hydroxyl radical (OH).

Sulfate produced catalytically through transition metal ions are formed on relatively large mineral dust particles, making them bigger than those formed through the reaction with hydrogen peroxide. Due to their size, they fall from the air at a faster rate – by force of gravity. The time frame for climate cooling by sulfate particles could therefore be shorter than has been believed.

Eliza Harris assumes that the models have overestimated the climate cooling effect of sulfate aerosols. So far it is not quantifiable to what degree Harris' discovery will impact climate prognoses. However, future models should consider the TMI catalysis reaction as an important pathway for the oxidation of sulfur dioxide, says the scientist. She thinks that the impact on climate models of European regions might probably be low, as mineral dust concentrations in the air are small and sulfur dioxide (SO2) emissions are declining. "In India and China, however, where sulfur dioxide emissions are expected to rise in the near future, combined with significantly higher concentrations of mineral dust in the air, the effect could be stronger", assumes Harris. Future studies will show.

The study, which has been published in the journal Science (Vol…), was conducted in collaboration with the following institutes: the Max Planck Institute for Chemistry in Mainz, the Leibniz Institute for Tropospheric Research in Leipzig, the Department of Atmospheric Science at Colorado State University, the Earth System Science Research Centre at the Institute of Geosciences at the University of Mainz, and the Institute of Atmospheric Physics at the University of Mainz.

Eliza Harris was recently awarded the Dieter Rampacher Prize as youngest doctoral candidate of the Max Planck Society in 2012.

Contact: Dr. Baerbel Sinha
baerbel.sinha@mpic.de
91-950-114-3967
Max-Planck-Gesellschaft

Why Bears? (Video)

Credit: Emmanuel Keller (CC)

"What if we could preserve wild spaces simply by protecting one family of animals?"

This film is for teachers, scientists, non-profits and people interested in bears and preserving wild spaces. This film was made possible by an anonymous donation and was produced in partnership with Wildlife Media.

What's good for bears is good for people and the planet.

Written by Chris Morgan & Aaron Straight.

Why Bears

 

Carbon Dioxide at NOAA’s Mauna Loa Observatory reaches new milestone: Tops 400 ppm

NOAA's Mauna Loa Observatory after a snowstorm. Courtesy of Mary Miller, Exploratorium

On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million (ppm) for the first time since measurements began in 1958. Independent measurements made by both NOAA and the Scripps Institution of Oceanography have been approaching this level during the past week. It marks an important milestone because Mauna Loa, as the oldest continuous carbon dioxide (CO2) measurement station in the world, is the primary global benchmark site for monitoring the increase of this potent heat-trapping gas.

Carbon dioxide pumped into the atmosphere by fossil fuel burning and other human activities is the most significant greenhouse gas (GHG) contributing to climate change. Its concentration has increased every year since scientists started making measurements on the slopes of the Mauna Loa volcano more than five decades ago. The rate of increase has accelerated since the measurements started, from about 0.7 ppm per year in the late 1950s to 2.1 ppm per year during the last 10 years.

“That increase is not a surprise to scientists,” said NOAA senior scientist Pieter Tans, with the Global Monitoring Division of NOAA’s Earth System Research Laboratory in Boulder, Colo. “The evidence is conclusive that the strong growth of global CO2 emissions from the burning of coal, oil, and natural gas is driving the acceleration.” 

Before the Industrial Revolution in the 19th century, global average CO2 was about 280 ppm. During the last 800,000 years, CO2 fluctuated between about 180 ppm during ice ages and 280 ppm during interglacial warm periods. Today’s rate of increase is more than 100 times faster than the increase that occurred when the last ice age ended.

It was researcher Charles David Keeling of the Scripps Institution of Oceanography, UC San Diego, who began measuring carbon dioxide at Mauna Loa in 1958, initiating now what is known as the “Keeling Curve.” His son, Ralph Keeling, also a geochemist at Scripps, has continued the Scripps measurement record since his father’s death in 2005.

“There’s no stopping CO2 from reaching 400 ppm,” said Ralph Keeling. “That’s now a done deal. But what happens from here on still matters to climate, and it’s still under our control. It mainly comes down to how much we continue to rely on fossil fuels for energy.”

NOAA scientists with the Global Monitoring Division have made around-the-clock measurements there since 1974. Having two programs independently measure the greenhouse gas provides confidence that the measurements are correct.

Moreover, similar increases of CO2 are seen all over the world by many international scientists. NOAA, for example, which runs a global, cooperative air sampling network, reported last year that all Arctic sites in its network reached 400 ppm for the first time. These high values were a prelude to what is now being observed at Mauna Loa, a site in the subtropics, this year. Sites in the Southern Hemisphere will follow during the next few years. The increase in the Northern Hemisphere is always a little ahead of the Southern Hemisphere because most of the emissions driving the CO2 increase take place in the north.

Once emitted, CO2 added to the atmosphere and oceans remains for thousands of years. Thus, climate changes forced by CO2 depend primarily on cumulative emissions, making it progressively more and more difficult to avoid further substantial climate change. 

Related Links:

• NOAA carbon dioxide data

• Scripps Institution of Oceanography carbon dioxide data

• NOAA’s Maua Loa Observatory

Time history of atmospheric carbon dioxide from 800,000 years ago until January, 2012.

 

Productivity increases with species diversity

150 years later, research result proves Darwin prediction

Environments containing species that are distantly related to one another are more productive than those containing closely related species, according to new research from the University of Toronto Scarborough (UTSC).

The experimental result from Marc William Cadotte confirms a prediction made by Charles Darwin in On the Origin of Species, first published in 1859. Darwin had said that a plot of land growing distantly related grasses would be more productive than a plot with a single species of grass.

Since then, many experiments have shown that multi-species plots are more productive. Cadotte's experiment showed for the first time that species with the greatest evolutionary distance from one another have the greatest productivity gains.

"If you have two species that can access different resources or do things in different ways, then having those two species together can enhance species function. What I've done is account for those differences by accounting for their evolutionary history," Cadotte says.

Cadotte grew 17 different plants in various combinations of one, two, or four species per plot. As in previous experiments, he found that multi-species plots produced more plant material. But when he analyzed the results he also found that combinations of plants that were distantly related to one another were more productive than combinations of plants that were closely related. So, for instance, a plot planted with goldenrod and the closely related black-eyed susan wasn't as productive as a plot with goldenrod and the more distantly related bluestem grass.

What's going on isn't mysterious, Cadotte says. Distantly related plants are more likely to require different resources and to fill different environmental niches – one might need more nitrogen, the other more phosphorus; one might have shallow roots, the other deep roots. So rather than competing with one another they complement one another.

What's interesting about his result is that evolutionary distance is all you need to know to predict productivity. The result suggests that as plant species disappear the Earth will become less productive, and plants will draw even less carbon from the atmosphere, possibly increasing the rate of global warming.

On the other hand, the results could give a valuable tool to conservation efforts. Environmentalists trying to restore damaged habitats could use the information to help them pick which combinations of species to introduce.

This research will be published in the upcoming edition of the Proceedings of the National Academy of Sciences of the United States (PNAS).

Contact: Dominic Ali
d.ali@utoronto.ca
416-978-6974
University of Toronto