Renewable energy has a natural fit with managing land for agricultural production, according to Dr Jonathan Scurlock, National Farmers Union (NFU) chief advisor on renewable energy.

Speaking to BBC Farming Today, Dr Scurlock noted that there has been increased interest from farmers in utilising their land for renewable energy, particularly with solar photovoltaics (PV).

“In the rows between the solar modules there will certainly be a need to keep the grass down, so sheep grazing is an obvious opportunity,” he explained. “We have had members expressing a considerable interest in perhaps combining solar farms with free range poultry.

“One further opportunity is the possibility of solar farms actually being used for bio-diversity benefit, especially for the under-planting of pollen and nectar mixtures or bird forage mixtures.”

Farmers could find that they will not see such high returns from the feed-in tariff, however. The government’s review into the incentive scheme proposes reducing the payments for large-scale renewables of more than 50kW.

However, the review also proposed an increase in the tariff for farm-scale anaerobic digestion.

Posted by Mark Stephens

Sign up for regular email updates to help you save money and energy

For more information please see: FIT review

View the original article here

Their work is published online in Springer’s journal, Climatic Change Letters.

Shale gas has become an increasingly important source of natural gas in the United States over the past decade. Shale gas is extracted by a high-volume hydraulic fracturing (fracking) process. Large volumes of water are forced under pressure into the shale to fracture and re-fracture the rock to boost gas flow. A significant amount of water returns to the surface as flow-back within the first few days to weeks after injection and is accompanied by large quantities of methane.

Howarth and team evaluated the greenhouse gas footprint of natural gas, obtained by high-volume hydraulic fracturing of shale formations, focusing on methane emissions. They analyzed the most recently published data — in particular, the technical background document on greenhouse gas emissions from the oil and gas industry (EPA 2010), as well as a report on natural gas losses on federal lands from the General Accountability Office (GAO 2010).

They calculated that, overall, during the life cycle of an average shale-gas well, between four to eight percent of the total production of the well is emitted to the atmosphere as methane, via routine venting and equipment leaks, as well as with flow-back return fluids during drill out following the fracturing of the shale formations. Routine production and downstream methane emissions are also large, but comparable to those of conventional gas.

Methane is a far more potent greenhouse gas than carbon dioxide, but methane also has a 10-fold shorter residence time in the atmosphere. As a result, its effect on global warming falls more rapidly. Methane dominates the greenhouse gas footprint for shale gas on a 20 year horizon, contributing up to three times more than does direct carbon dioxide emission. At this time scale, the footprint for shale gas is at least 20 percent greater than that for coal, and perhaps twice as great.

Robert Howarth concludes: “The large greenhouse gas footprint of shale gas undercuts the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming. The full footprint should be used in planning for alternative energy futures that adequately consider global climate change.”

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Springer Science+Business Media, via AlphaGalileo.

Journal Reference:

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Natural Sequence Farming is a descriptor used when sustainable agriculture mimics the once highly efficient functions of the Australian landscape. NSF pioneer Peter Andrews of Denman in New South Wales and coordinator of the NSF movement, Duane Norris of Hardy’s Bay, New South Wales explain how NSF techniques could re-couple environmental carbon and water cycles not only to improve farming yields but to avoid soil erosion and reduce carbon dioxide emissions.

Agricultural practices such as clearing, burning, plowing, draining, and irrigation, have become commonplace across the Australian continent, as they have elsewhere. Their effect on the organic carbon content of soil has led to a decline in soil quality across farmland on the continent with levels currently a tenth of what they were 200 years ago prior to the major European settling of Australia.

Andrews and Norris point out that this has had implications for atmospheric carbon dioxide levels and will continue to impact on global warming if farming practices are not modified. “Soils hold twice as much carbon as the atmosphere, and three times as much as vegetation,” the team explains, “But carbon in soil exposed by common agricultural practices leads to the oxidation of the carbon and the release of carbon dioxide into the atmosphere.” Estimates suggest that soils that once contained carbon matter 4,000 to 10,000 years old, are now holding carbon that is a mere two years old because poor management of livestock grazing leaves soil de-vegetated and in an oxidizing state.

Plants extract carbon from carbon dioxide in the air by photosynthesis, the team says. This carbon is critical to soil health and plant fertility, but it is lost when a ploughed paddock is left bare with no plant cover. More carbon is released when grassland and trees are cleared. However, when vegetation is allowed to break down, even if it is weedy cover, the carbon content of the soil is raised and growing conditions improve.

But plants also have another critical function — relevant to both soil fertility and to climate stabilization. This is the atmospheric cooling that takes place through the evaporation of moisture from leaves, as it rises to form rain clouds, and then falls again restoring of the small water cycle to a local area. In this respect, hands-on NSF research in Australia converges with cutting edge scientific research elsewhere.

The team adds that careful water management, planting, and mulch farming all work together in NSF practices so remediating eroded land. NSF techniques have been developed to restore ecosystems by re-coupling the carbon and water cycles and could overcome the calamitous decline in soil carbon content caused by oxidation, soil erosion and loss to the sea because of fast-running water flows and floods.

There are four guidelines for Natural Sequence Farming:

The researchers recognize that Australians cannot turn the clock back 100,000 years to recreate the forested continent of mega fauna and sediment-carrying flood plains that existed before humans arrived.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Inderscience Publishers, via EurekAlert!, a service of AAAS.

Journal Reference:

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

View the original article here

View the original article here

The study was led by Dr Ian Harding and Prof John Marshall of the University of Southampton’s School of Ocean and Earth Science (SOES), based at the National Oceanography Centre, Southampton.

Around 56 million years ago there was a period of global warming called the Paleocene-Eocene Thermal Maximum (PETM), during which global sea surface temperatures increased by approximately 5°C.

The warming of the oceans led to profound ecological changes, including the widespread extinction of many types of foraminifera, tiny single-celled organisms with distinctive shells. Plankton that had previously only prospered in tropical and subtropical waters migrated to higher latitudes. Similar changes occurred on the land, with many animals and plants extending their distributions towards the poles.

“Although environmental changes associated with the PETM at low- to mid-latitude settings and high southern latitudes are well documented, we know less about these changes at high northern latitudes,” explained Dr Harding.

Information about the Arctic environment during the PETM has come predominantly from sediment cores drilled from under the pack ice on the Lomonosov Ridge (~ 88°N) by the Integrated Ocean Drilling Program (IODP Site 302-4A). However, these cores do not span the entire PETM and therefore do not provide a complete picture.

“Information from other Arctic sites is needed for a better understanding of PETM environmental conditions, such data can then in turn be used in computer models which will improve our understanding not only of past climatic conditions but also enhance our ability to predict future perturbations,” said Dr Harding.

To help fill this knowledge gap, Dr Harding’s team turned to a site (~78 °N) on Spitsbergen in the high Arctic. Here, 2.5-kilometre-thick sediments span the critical period. During the PETM, the site would have been at around 75 °N, the difference in position being due to the slow movement of tectonic plates over millions of years.

Through analyses of plankton and the chemical and magnetic characteristics of the sediments, they were unambiguously able to identify a 15-metre succession of exposed sediment representing the approximately 170 thousand year PETM event.

At the base of the segment they found the preserved remains of the cyst-forming dinoflagellate Apectodinium augustum, a planktonic species diagnostic of the PETM across the globe. In fact, the species was already present in Spitsbergen before the shift in carbon isotope composition formally marking the onset of the PETM, suggesting that environment change was by then already well underway.

Along with data from other sites, their Arctic evidence suggests not only that sea level began to rise well before the formal onset of the PETM, but also that it peaked about 13,000 years into the period. At the same time, increased surface-water run-off from the land dampened water-column mixing and led to stratification, with an upper freshened layer that overlay denser, more saline seawater beneath.

By carefully comparing their results with those from IODP Site 302-4A to the north, they found evidence for regional differences in the environmental manifestations of the PETM in high northern latitudes. For example, the evidence from the IODP site suggests that the sunlit surface layer of the ocean was often depleted of oxygen, the results from Spitsbergen suggest that oxygen depletion was largely restricted to the bottom waters and sediments. In addition, they found that pollen from flowering plants was scarce, unlike at the IODP site, suggesting that conditions around the Spitsbergen Central Basin may not have been conducive to the growth of flowering plants during the PETM.

“Because this geologically short-lived event is represented by such an expanded section at Spitsbergen by comparison to other deep water sites, this locality has provided us with opportunities for further high-resolution studies of the PETM, which we are currently preparing for publication,” concluded Dr Harding.

The researchers are Ian Harding, Adam Charles , John Marshall, Heiko Pälike, Paul Wilson, Edward Jarvis, Robert Thorne, Emily Morris, Rebecca Moremon, Richard Pearce and Shir Akbari of SOES, and Andrew Roberts of the Australian National University, Canberra.

Preliminary field work was funded by The Millennium Atlas Company Limited, and a second expedition with other members of the palaeo-Arctic Climates and Environments (pACE) group was funded by the Worldwide Universities Network.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by National Oceanography Centre, Southampton (UK).

Journal Reference:

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Populations of species at the edges of their distribution areas, as is the case with the ‘lady’s slipper’ orchid (Cypripedium calceolus) on the southern side of the Pyrenees, have always been considered to be more vulnerable than those at the centre of their range.

This is what led to researchers from the Pyrenean Institute of Ecology (CSIC) publishing the first ever count-based plant demographic model to find out whether populations of this rare Euro-Asian orchid are in a worse situation than those in countries such as Poland or Estonia.

“The populations on the southern edges of the Pyrenees are similar in size, reproduce better, and are as stable or even growing at a faster pace than those in Central Europe,” says María B. García, lead author of the study and a researcher at the Pyrenean Institute of Ecology (CSIC).

According to the study, published in the journal Conservation Biology, this “unusual” result seems to be related to reforestation in the areas of the Pyrenees studied. The ending of traditional practices such as farming and grazing could help some endangered forest plants to recover.

“For a plant that is used to colder temperatures (such as in Central and Northern Europe), reforestation in more southerly areas could represent an improvement to its habitat, thereby leading to an increase in the population growth rate,” says García, who confirmed that the highest such rate found to date is in the Pyrenees.

The research also highlights the fact that landscape changes and the expansion of forests over the past 50 years in mountainous regions are providing “new opportunities” and giving “hope for the recovery of forest species at the edge of their range against a future backdrop dominated by biodiversity loss.”

The duration of the study (from 1997 to 2010) was of key importance in arriving at these conclusions. Before now “there have not been any similar studies over such a long time,” the researcher explains.

The resurgence of an endangered plant

Cypripedium calceolus is classified as ‘endangered’ in the whole of Europe and “represents almost 100 forest plants that are at the limits of their range on the southern slopes of the Pyrenees,” the researcher points out. Climate change and global warming are threat factors that could have dramatic implications for orchids, as well as other plant species. “However, at this time of global warming, the increase in forest area along this mountain range could be benefiting this group of species,” the biologist says.

In the absence of severe manmade alterations to the environment, the immediate future for these orchid populations in the Pyrenees “seems to be favourable,” the study concludes.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Plataforma SINC, via AlphaGalileo.

Journal Reference:

Note: If no author is given, the source is cited instead.

View the original article here

Read more on Business Times

CleanTech Corridor Competition Announces Winners
Winners expressed their visions of a future with clean technology

Read more on NBC Los Angeles

Green Fields: Natural gas prices to stay stable through 2011
The U.S. Department of Energy has some good news on natural gas, reporting that supplies are ample and prices are expected to remain stable through next year.

Read more on The Des Moines Register