Carbon Dioxide In Atmosphere Can Now Be Measured From Space

SOURCE

ScienceDaily (Apr. 12, 2009) — INESC Porto developed a technology, together with ESA – European Space Agency, that enables a more effective measurement of gases in the atmosphere comparatively to the currently used techniques. With this technology, it will be possible to measure gases, such as carbon dioxide, methane, nitrous oxide and ozone – the gases responsible for global warming and greenhouse effects.

The system developed by INESC Porto’s Optoelectronics and Electronic System Unit (UOSE) has a high potential of applicability in satellites due to its efficiency, compactness and reduced volume and mass. The satellites equipped with INESC Porto’s optical fibre filters will be able to detect pollutant gases in the Earth’s atmosphere in concentrations less than 1 km high, at an altitude of 400 km.
The partnership between INESC Porto and ESA started in 2006 and is now showing its first signs of success with the development of an optical fibre filter that is capable of measuring carbon dioxide levels from space.
Other than carbon dioxide, this technology is capable of providing a precise measurement of other pollutant gases, such as methane gas, nitrous oxide and ozone, besides measuring levels of humidity, atmospheric pressure, temperature and wind speed. Thus, this is an essential tool made in Portugal for research on climate change, a step forward to the control of greenhouse gases in the battle against global warming.
If it is applied to satellites, the filter developed by INESC Porto is capable of monitoring all kinds of pollutant gas concentrations less than 1 km high, 50 km wide, at an altitude of 400 km. Unlike what the currently used technologies - atmospheric balloons and airplanes equipped for that purpose -provide, with the filters created by INESC Porto, it will be possible to map the atmosphere three-dimensionally, with a higher resolution and from a single position.
The technology's potential of application in orbital systems and scientific missions has to do with its unique features: efficiency, compactness and reduced volume and mass. The technology developed by INESC Porto consists of an ultra-narrow spectral tuneable and heat-reflecting filter based on optical fibre technology that can be used in order to monitor the atmosphere with the reflection of laser impulses. Using the radiation's time of flight and absorption, it will be possible to extract profiles of pollutant gas concentrations in the atmosphere.
Adapted from materials provided by INESC PORTO.

Potential To Amass More Carbon In Eastern North American Forests

SOURCE

ScienceDaily (Apr. 11, 2009) — With climate change looming, the hunt for places that can soak up carbon dioxide from the atmosphere is on.

Obvious "sinks" for the greenhouse gas include the oceans and the enormous trees of tropical rainforests. But temperate forests also play a role, and new research now suggests they can store more carbon than previously thought.
In a study that drew on both historical and present-day datasets, Jeanine Rhemtulla of McGill University and David Mladenoff and Murray Clayton of University of Wisconsin-Madison quantified and compared the above-ground carbon held in the forest trees of Wisconsin just prior to European settlement and widespread logging, and the total carbon they contain today.
Writing in the current issue of the Proceedings of the National Academy of Sciences, the researchers report that despite decades of forest recovery, Wisconsin's woodlands still only hold about two-thirds the carbon of pre-settlement times — suggesting substantial room for them to accumulate more.
"There's probably more potential (to store carbon) than people were considering," says Mladenoff. "There's still a big difference between what was once there and what's there now."
He adds that the true storage potential is probably at least two-fold higher than what he and Rhemtulla calculated, since they factored in only the live, above-ground biomass of tree trunks and crowns, and not the carbon stored in roots and soil.
The results have implications not only for Wisconsin, but also for regions across eastern North America where forests were leveled historically to make room for agriculture, and then grew up again as settlers abandoned their farms and headed west. In Wisconsin, for example, forest biomass and carbon have been steadily recovering since the peak of agricultural clearing in the 1930s, while those in the northeastern U.S. have been rebounding for about 125 years.
Yet, it's precisely because many temperate forests have been recovering for so long that people tend to assume their potential as carbon sinks is "maxed out," says Mladenoff.
"Our results suggest we need to rethink this," he says. "Rather than there being an intrinsic limit on how much carbon a forest can store, how we use the forest — how much we log, how we manage — may be more important."
The findings come amid sweeping discussions of international carbon treaties and accounting systems that are designed to reduce CO2 emissions and combat climate change. In the future, for instance, countries might earn credits for maintaining carbon-rich old-growth forests, or replanting trees on lands logged off previously for agriculture.
Areas that once supported large amounts of forest biomass might also be good sites for growing plantations of hybrid poplar and other biofuels crops, says Mladenoff. But, he cautions, any move toward planting more land in trees must be weighed against competing social and economic factors, such as the need for farmland.
"The landscape is full," says Mladenoff. "So if we're going to add something like forests, we're going to need to take something out."
That certainly seems to be true in Wisconsin. Based on historic carbon levels, the researchers' analysis found that much of the best land for growing trees is the north-central region and along northern Lake Michigan. If those lands could be reforested to pre-settlement levels, the scientists estimate they could add 150 teragrams of carbon (150 million metric tons) to the state's current total of approximately 275 teragrams.
The problem, however, is that most of those lands are still being farmed, setting up an interesting dilemma for policy makers: how to weigh the current economic benefit of agriculture against the future environmental benefit of carbon storage.
"Because we often forget the invisible services, like climate regulation, that ecosystems provide to us for free, we don't usually factor them into our decision making," says Rhemtulla. "But this will need to change if we're going to find ways to meet our immediate needs without compromising critical services over the long term."
Journal reference:
Jeanine M. Rhemtulla, David J. Mladenoff, and Murray K. Clayton. Historical forest baselines reveal potential for continued carbon sequestration. Proceedings of the National Academy of Sciences, 2009; DOI: 10.1073/pnas.0810076106
Adapted from materials provided by University of Wisconsin-Madison.

New Link Between The Evolution Of Complex Life Forms On Earth And Nickel And Methane Gas

SOURCE

ScienceDaily (Apr. 9, 2009) — The Earth's original atmosphere held very little oxygen. This began to change around 2.4 billion years ago when oxygen levels increased dramatically during what scientists call the "Great Oxidation Event." The cause of this event has puzzled scientists, but researchers writing in Nature have found indications in ancient sedimentary rocks that it may have been linked to a drop in the level of dissolved nickel in seawater.

"The Great Oxidation Event is what irreversibly changed surface environments on Earth and ultimately made advanced life possible," says research team member Dominic Papineau of the Carnegie Institution's Geophysical Laboratory. "It was a major turning point in the evolution of our planet, and we are getting closer to understanding how it occurred."
The researchers, led by Kurt Konhauser of the University of Alberta in Edmonton, analyzed the trace element composition of sedimentary rocks known as banded-iron formations, or BIFs, from dozens of different localities around the world, ranging in age from 3,800 to 550 million years. Banded iron formations are unique, water-laid deposits often found in extremely old rock strata that formed before the atmosphere or oceans contained abundant oxygen. As their name implies, they are made of alternating bands of iron and silicate minerals. They also contain minor amounts of nickel and other trace elements.
Nickel exists in today's oceans in trace amounts, but was up to 400 times more abundant in the Earth's primordial oceans. Methane-producing microorganisms, called methanogens, thrive in such environments, and the methane they released to the atmosphere might have prevented the buildup of oxygen gas, which would have reacted with the methane to produce carbon dioxide and water. A drop in nickel concentration would have led to a "nickel famine" for the methanogens, who rely on nickel-based enzymes for key metabolic processes. Algae and other organisms that release oxygen during photosynthesis use different enzymes, and so would have been less affected by the nickel famine. As a result, atmospheric methane would have declined, and the conditions for the rise of oxygen would have been set in place.
The researchers found that nickel levels in the BIFs began dropping around 2.7 billion years ago and by 2.5 billion years ago was about half its earlier value. "The timing fits very well. The drop in nickel could have set the stage for the Great Oxidation Event," says Papineau. "And from what we know about living methanogens, lower levels of nickel would have severely cut back methane production."
What caused the drop in nickel? The researchers point to geologic changes that were occurring during the interval. During earlier phases of the Earth's history, while its mantle was extremely hot, lavas from volcanic eruptions would have been relatively high in nickel. Erosion would have washed the nickel into the sea, keeping levels high. But as the mantle cooled, and the chemistry of lavas changed, volcanoes spewed out less nickel, and less would have found its way to the sea.
"The nickel connection was not something anyone had considered before," says Papineau. "It's just a trace element in seawater, but our study indicates that it may have had a huge impact on the Earth's environment and on the history of life."
Dominic Papineau's research is supported by the NASA Exobiology and Evolutionary Biology Program and from the Fond québécois de la recherche sur la nature et les technologies.
Journal reference:
Konhauser et al. Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event. Nature, 2009; 458 (7239): 750 DOI: 10.1038/nature07858
Adapted from materials provided by Carnegie Institution.

Satellite Snow Maps Help Reindeer Herders Adapt To A Changing Arctic

SOURCE

ScienceDaily (Apr. 10, 2009) — Arctic reindeer herders are facing the challenges of adapting to climate change as a warmer Arctic climate makes it harder for herds to find food and navigate. To help them adapt, the ESA-backed Polar View initiative is providing them with satellite-based snow maps.

"Snow is of paramount importance for reindeer herding because its quality determines whether reindeer are able to access the pastures that lie beneath it for much of the year," said Anders Oskal, the Director of the International Centre for Reindeer Husbandry (ICR). "Detailed circumpolar snow information is, thus, becoming increasingly important following the recent changes in the Arctic climate."
Oskal is working with Sámi reindeer herders in Finnmark, Norway, to help them maintain and develop sustainable reindeer husbandry. According to him, Finnmark is the area of Norway that is predicted to experience the largest temperature increases, raising concerns about whether ice layers will form over pastures preventing reindeer from foraging.
For this reason, ICR partnered with Polar View to examine how satellite observations could help by gathering information on snow and snow change in a timely and accurate manner for such vast circumpolar regions. Under the Polar View initiative, Kongsberg Satellite Services (KSAT) have been providing snow melt maps for Norway and Sweden and Eurasia snow cover maps for the last 18 months.
"The experience so far has definitely been positive, and the reindeer herders are extremely interested in the future utilisation of Polar View products that can relate important information about local snow conditions," Oskal said. "These products could have important consequences for herders’ decisions regarding winter pasture quality and potential migration routes."
In addition to climate change, reindeer herders also have to face a loss of pastures due to infrastructure development, such as roads, hydroelectric power dams and cabin resorts. In the future, ICR and Polar View may partner again to monitor the different forms of land use change over time.
Products from Polar View have also been used as input for an International Polar Year Project – IPY EALÁT-Network Study – on reindeer herding and adaptation to climate change.
The two Polar View snow services are provided by KSAT in partnership with the Northern Research Institute, the Norwegian Computing Centre and the Finnish Meteorological Institute.
Polar View is supported by ESA and the European Commission (EC) with participation from the Canadian Space Agency. It was established under the Global Monitoring for Environment and Security (GMES) programme – a joint initiative between ESA and the EC to combine all available space- and ground-based information sources to develop an independent European environmental monitoring capacity from planetary to local scales.
Adapted from materials provided by European Space Agency.