What's in the grime tarnishing the Taj Mahal?

Taj Mahal

Every several years, workers apply a clay mask to India's iconic but yellowing Taj Mahal to remove layers of grime and reveal the white marble underneath. Now scientists are getting to the bottom of what kinds of pollutants are discoloring one of the world's celebrated wonders. Their findings, published in the ACS journal Environmental Science & Technology, could help inform efforts to protect the mausoleum and other surfaces from pollution.

Mike H. Bergin, Sachchida Nand Tripathi and colleagues note that Indian officials have tried to reduce the effects of pollution on the Taj Mahal by restricting nearby traffic and limiting local industrial emissions. But despite regulations and an occasional deep clean, the domes and minarets continue to accrue a layer of soot. So far, no published studies have looked closely at what specific compounds are causing it to appear yellow. Bergin's and Tripathi's teams wanted to find out.

The researchers analyzed particles in the air and on marble samples near the main dome over several months. Using a novel method they developed, the team estimated how these specks reflect light and therefore affect the color of the building. They conclude that black carbon and brown carbon from the burning of trash, fuels and other materials are among the primary pollutants tarnishing the Taj Mahal. In the future, their approach could be used to craft strategies to address the chronic yellowing and improve air quality, they say.

The authors acknowledge funding from the Indo-U.S. Science and Technology Forum, the Environmental Protection Agency and the National Science Foundation.

Source: American Chemical Society

The Composite plane life cycle assessment shows lighter planes are the future

Boeing Dreamliner 787. Credit: Image courtesy of University of Sheffield

A global fleet of composite planes could reduce carbon emissions by up to 15 per cent, but the lighter planes alone will not enable the aviation industry to meet its emissions targets, according to new research.

The study, by the Universities of Sheffield, Cambridge and University College London, is the first to carry out a comprehensive life cycle assessment (LCA) of a composite plane, such as the Boeing Dreamliner 787 or Airbus 350, and extrapolate the results to the global fleet.
The LCA covers manufacture, use and disposal, using publicly available information on the Boeing Dreamliner 787 fuselage and from the supply chain -- such as the energy usage of the robots that construct the planes. The study compares the results to the traditional -- and heavier -- aluminium planes.

Emissions during the manufacture of composite planes are over double those of aluminium planes. But because the lighter aircraft use significantly less fuel, these increased emissions are offset after just a few international flights. Over its lifetime, a composite plane creates up to 20 per cent fewer CO2 emissions than its aluminium equivalent.

Professor in Advanced Materials Technologies at the University of Sheffield, Alma Hodzic, said: "This study shows that the fuel consumption savings with composites far outweigh the increased environmental impact from their manufacture. Despite ongoing debates within the industry, the environmental and financial savings from composites mean that these materials offer a much better solution."

The researchers fed the data from the LCA into a wider transport model to gauge the impact on CO2 emissions as composite planes are introduced into the global fleet over the next 25 years, taking into account other factors including population, economic prosperity, oil prices and speed of adoption of the new technology.

The study -- published in the International Journal of Life Cycle Assessment -- estimated that by 2050, composite planes could reduce emissions from the global fleet by 14-15 per cent relative to a fleet that maintains its existing aluminium-based configuration.

Professor in Energy and Transport at UCL, Andreas Schäfer, explains: "The overall emissions reduction for the global fleet is lower than the reduction for an individual plane, partly, because by 2050, not all the fleet will be of composite construction. New planes entering the fleet before 2020 could still be in use by 2050, but the faster the uptake of this technology, the greater the environmental benefits will be."

Dr Lynette Dray from the University of Cambridge added: "Given that global air traffic is projected to increase four-fold between now and 2050, changing the materials used could avoid 500 million tonnes of CO2 emissions in 2050 alone, a value that roughly corresponds to current emission levels."

Professor Hodzic commented: "The industry target is to halve CO2 emissions for all aircrafts by 2020 and while composites will contribute to this, it cannot be achieved by the introduction of lighter composite planes alone. However, our findings show that composites -- alongside other technology and efficiency measures -- should be part of the picture."

Source: University of Sheffield

New laws threaten Brazil's unique ecosystems

Brazil's globally significant ecosystems could be exposed to mining and dams if proposals currently being debated by the Brazilian Congress go ahead, according to researchers publishing in the journal Science this week. Credit: Alexander C. Lees

Brazil´s globally significant ecosystems could be exposed to mining and dams if proposals currently being debated by the Brazilian Congress go ahead, according to researchers publishing in the journal Science this week.

The new report by a group of Brazilian and British researchers comes in the wake of Brazil´s recent presidential elections. It warns that new legislation could pose a serious threat to protected areas, weakening Brazil's international status as an environmental leader.

One of the proposals of particular concern is the call to open up 10% of the most strictly protected areas to mining. In a new analysis, the research shows that at least 20% of all Brazil´s most strictly protected areas and reserves for indigenous people overlap with areas that have been registered as under consideration for mining. In addition, many of the river systems associated with protected areas will be influenced by the construction of large hydroelectric dams.

The threat that this mining and hydropower poses to Brazil's ecosystems is not trivial. Areas of registered interest for mining include 34,117 km2 that are currently classified as strictly protected areas -- including National Parks, Biological Reserves and Wildlife Refuges. This is equivalent to an area the size of Switzerland. The situation is worse for indigenous lands, 28% of which, or 281,443 km2, overlap with areas of registered mining interest -- an area larger than the whole of the UK or the state of São Paulo.

In recent years Brazil has enjoyed increasing recognition as a world leader in combatting environmental destruction. Brazil´s protected area network is the largest in the world, while improved environmental governance in private lands has contributed to an 80% reduction in the rate of deforestation in the Brazilian Amazon over the last decade. Yet these new proposals could threaten these recent successes and undermine Brazil's reputation.

Dr Joice Ferreira, a scientist at Brazil´s agricultural research institute, Embrapa, and lead author of the study, said: "The purpose of this analysis is not to say that Brazil´s development should not benefit from its abundant natural resources, but that we should not squander our hard-won record of success and leadership in favor of fast-tracked and poorly planned development projects that leave a long legacy of environmental damage. It is possible to manage our development in a more sustainable way."

Co-author Dr Jos Barlow, a researcher at Lancaster University and a visiting professor in Brazil, said: "Rather than exploiting protected areas for short-term gains, Brazil should treasure them for the long-term benefits they can provide to society. The recent water shortages in the south east of Brazil emphasize the importance of protecting native vegetation across the country."

The authors of the study also warn that the proposals for minimizing and mitigating the environmental damage of large-scale development projects are so inadequate that even if only a fraction of these mining concessions were approved then the impacts could be enormous, especially in Brazil´s most threatened ecosystems.

Dr. Luiz Aragão a co-author of the study from Brazil´s federal space agency, INPE and the University of Exeter said: "Our concern is that even if the proposed mitigation actions were put in place they are oversimplified because they fail to take account of the indirect effects of mega-projects.
"These projects can involve thousands of workers and lead to rapid local population growth. This, combined with new roads and access routes, is a recipe for the emergence of new deforestation frontiers." explains Luiz.

The study highlights the fact that these worrying changes reflect an important shift in the support shown by Brazil´s federal government to environmental protection. These concerns come on the back of other recent changes, including the partial dismantling of Brazil´s protected area system to make way for development -- with some 44,100 km2 lost since 2008 due to downsizing or abolishment -- and the weakening of the Forest Code that gave an amnesty to landowners who deforested illegally in the past.

"Beyond the conservation and stewardship of its own biodiversity and environmental resources, so vital to the wellbeing of its citizens, Brazil plays a vital role in motivating and supporting the adoption of more sustainable development trajectories around the world," said Toby Gardner, of Stockholm Environment Institute, one of the authors of the study who has worked in the country for more than a decade. "Yet this standing is now in jeopardy."

Dr Joice Ferreira said: "The newly elected government has the chance to set the record straight and point Brazil firmly on a path of sustainable development. The authors of this report call on President Dilma and her government to ensure that individual development initiatives are subject to a comprehensive, socially inclusive, evidence-based and long-term cost-benefit analysis that compares potential environmental and social impacts against alternative development options. And also to ensure that Brazil´s renowned protected area network is given the resources it needs to manage our ecosystems sustainably.

"Above all we ask the Government to guarantee that important decisions regarding the management of Brazil´s natural resources involve the full and democratic participation of Brazilian society."

Source: Lancaster University

Hack the planet? Geoengineering research, ethics, governance explored

A conceptualized image of a wind-powered, remotely controlled ship that could seed clouds over the ocean to deflect sunlight.

Hacking Earth's climate to counteract global warming -- a subject that elicits strong reactions from both sides -- is the topic of a December special issue of the journal Climatic Change. A dozen research papers include the most detailed description yet of the proposed Oxford Principles to govern geoengineering research, as well as surveys on the technical hurdles, ethics and regulatory issues related to deliberately manipulating the planet's climate.

University of Washington researchers led the three-year project to gather leading thinkers and publish a snapshot of a field that they say is rapidly gaining credibility in the scientific community.
"In the past five years or so, geoengineering has moved from the realm of quackery to being the subject of scientific research," said co-editor Rob Wood, a UW associate professor of atmospheric sciences. "We wanted to contribute to a serious intellectual discourse."

Creating clouds over the ocean that would reflect back sunlight is the subject of a chapter by Wood, whose research is on the interaction among air pollution, clouds and climate. He and co-author Tom Ackerman, a UW atmospheric sciences professor, look at what it would take to test the idea with a field experiment.

"I don't want to prove it right, I just want to know if it's feasible," Wood said. "If you look at the projections for how much Earth's air temperature is supposed to warm over the next century, it is frightening. We should at least know the options. Is geoengineering feasible if there were to be what people call a 'climate emergency'?"

Also explored in the journal issue is the idea of injecting reflective particles into the stratosphere, subject of a 2006 paper in Climatic Change by Nobel Prize-winning chemist Paul Crutzen and central to Seattle entrepreneur Nathan Myhrvold's proposed StratoShield. Yet another idea is iron fertilization of ocean microbes, though Wood said preliminary tests suggest this is not as successful at drawing carbon dioxide out of the atmosphere as its proponents had originally thought.

How to govern geoengineering is a topic of hot debate. In one paper, U.K. authors flesh out the so-called Oxford Principles, which suggest how geoengineering could be regulated as a global public good. The five principles described in the paper concern the research, publication, assessment and deployment of geoengineering techniques.

Many of the authors spoke at the UW during a 2011 seminar series, and more attended a 2012 workshop where they developed their paper ideas.

While discussions were civil, Wood said, the contributors didn't all agree. A UW philosopher questions whether geoengineering can even be described in the Oxford Principles as a global public good.

"Just spraying sulfates into the stratosphere is not the kind of thing that necessarily benefits everyone, so in that sense it seems a mistake to call it a global public good," said co-editor Stephen Gardiner, a UW philosophy professor who has written a book on ethics and climate change. There are decisions about how to conduct sulfate spraying, he writes, and potential tradeoffs between short-term benefits and long-term risks.

Gardiner also questions whether something should be done in people's benefit but without their permission, and if accepting geoengineering as a necessary evil ignores other science or policy options.

He's not the only social scientist to be looking at climate issues.
"A lot of people, from across the academy, are getting interested in the Anthropocene -- the idea that we may have entered a new geological era where human influence is a dominant feature, and what that means for various issues," Gardiner said.

The collection aims to prompt a serious academic discussion the editors say has so far been lacking.
"It's an interdisciplinary discussion with an emphasis on the research angle -- whether and how we should be researching geoengineering," said co-editor Lauren Hartzell-Nichols, a UW lecturer in philosophy. "We hope it helps people think about this issue in a more interdisciplinary and integrated way."

The seminars and workshop that led to the issue's creation were supported by the UW College of the Environment.

Source: University of Washington

The Hydraulic fracturing in Michigan investigated

Geology of Michigan. Credit: MDEQ

University of Michigan researchers today released seven technical reports that together form the most comprehensive Michigan-focused resource on hydraulic fracturing, the controversial natural gas and oil extraction process commonly known as fracking.

The studies, totaling nearly 200 pages, examine seven critical topics related to the use of hydraulic fracturing in Michigan, with an emphasis on high-volume methods: technology, geology and hydrogeology, environment and ecology, public health, policy and law, economics, and public perceptions.

While considerable natural gas reserves are believed to exist in the state and high-volume hydraulic fracturing has the potential to help access them, possible impacts to the environment and to public health must be addressed, the U-M researchers concluded.

Though modern high-volume hydraulic fracturing is not widely used in Michigan today, a main premise of the U-M study is that the technique could become more widespread due to a desire for job creation, economic growth, energy independence and cleaner fuels.

"There's a lot of interest in high-volume hydraulic fracturing, but there really isn't much activity at the moment in Michigan," said John Callewaert, project director and director of integrated assessment at U-M's Graham Sustainability Institute, which is overseeing the project. "That's why now is a good time to do this assessment."

These reports conclude the first phase of a two-year U-M project known formally as the Hydraulic Fracturing in Michigan Integrated Assessment. The seven documents -- which should not be characterized or cited as final products of the integrated assessment -- provide a solid informational foundation for the project's next phase, an analysis of various hydraulic fracturing policy options. That analysis is expected to be completed in mid-2014 and will be shared with government officials, industry experts, other academics, advocacy groups and the general public.

"Nothing like this has been done before in Michigan," Callewaert said. "Having this comprehensive, state-specific set of reports will be an invaluable resource that will help guide future decision-making on this issue -- and hopefully will help Michigan avoid some of the pitfalls encountered in other states."

Conclusions of the reports, which were written by faculty-led, student-staffed teams from various disciplines, include:

• Technology. In view of the current low price of natural gas, the high cost of drilling deep shale formations and the absence of new oil discoveries, it is unlikely that there will be significant growth of the oil and gas industry in Michigan in the near-term future. However, considerable reserves of natural gas are believed to exist in deep shale formations such as the Utica-Collingwood, which underlies much of Michigan and eastern Lake Huron and extends into Ontario, Canada.

• Geology/hydrogeology. A recent flurry of mineral rights acquisitions in the state associated with exploratory drilling suggests the potential for growth in natural gas production through high-volume hydraulic fracturing, though only a handful of such wells have been drilled to date. "Michigan is thus in a unique position to assess the future of high-volume hydraulic fracturing before the gas boom begins."

• Environment/ecology. Potential impacts of hydraulic fracturing on the environment are significant and include increased erosion and sedimentation, increased risk of aquatic contamination from chemical spills or equipment runoff, habitat fragmentation and resulting impacts on aquatic and terrestrial organisms, loss of stream riparian zones, and reduction of surface waters available to plants and animals due to the lowering of groundwater levels.

• Public health. Possible hazards in the surrounding environment include impaired local and regional air quality, water pollution and degradation of ecosystems. Possible hazards in nearby communities include increased traffic and motor vehicle accidents, stress related to risk perception among residents, and boomtown-associated effects such as a strained health care system and road degradation.

• Policy/law. The state is the primary source of law and policy governing hydraulic fracturing in Michigan. The operator of a high-volume hydraulically fractured well must disclose the hazardous constituents of chemical additives to the state Department of Environmental Quality for each additive within 60 days of well completion. Unlike most other states, DEQ does not require operators to report toFracFocus.org, a nationwide chemical disclosure registry. • Economics. The gas extraction industry creates employment and income for Michigan, but the employment effects are modest compared with other industries and not large enough to "make or break" the state's economy. In the future, the number of technical jobs in the industry will likely increase, while less-skilled laborer positions will decline.

• Public perceptions. A slight majority of Michigan residents believe the benefits of fracking outweigh the risks, but significant concerns remain about the potential impacts to human health, the environment and groundwater quality. The public tends to view the word "fracking" as the entirety of the natural gas development process, from leasing and permitting, to drilling and well completion, to transporting and storing wastewater and chemicals. Industry and regulatory agencies hold a much narrower definition that is limited to the process of injecting hydraulic fracturing fluids into a well. These differences in perceived meaning can lead to miscommunications that ultimately increase mistrust among stakeholders.

In fracking, water, sand and chemicals (in a mix known as hydraulic fracturing fluid) are injected under high pressure deep underground to crack sedimentary rocks, such as shale, and free trapped natural gas or oil. Though the process has been used for more than half a century to improve well production, recent technical advances have helped unlock vast stores of previously inaccessible natural gas and oil, resulting in a boom in some parts of the United States.

Chief among the technical advances are directional drilling and high-volume hydraulic fracturing, which are often used together. In directional drilling, the well operator bores vertically down to the rock formation, then follows the formation horizontally. High-volume fracking -- the focus of recent attention and public concern -- is defined by the state of Michigan as a well that uses more than 100,000 gallons of hydraulic fracturing fluid. For reference, an Olympic-size swimming pool holds about 660,000 gallons of water.

Since the late 1940s, an estimated 12,000 gas and oil wells have been drilled in Michigan using hydraulic fracturing, without any reported contamination issues. Most of those wells have been relatively shallow vertical wells that each used about 50,000 gallons of water.

But recently, a small number of deep, directionally drilled, high-volume hydraulically fractured wells have been completed in the northern part of the Lower Peninsula. Those wells sometimes use several million gallons of water, and one Michigan well required more than 20 million gallons.

Since 2010, when the Petoskey Pioneer Well spurred interest in high-volume hydraulically fractured wells in Michigan, 19 such wells are known to have been completed in the state, according to Sara Gosman, a lecturer at the U-M Law School and author of the technical report on policy/law.

In the public perceptions report, authors Kim Wolske and Andrew Hoffman of the U-M Erb Institute for Global Sustainable Enterprise note that chemical additives in high-volume hydraulic fracturing fluids "remain a primary point of contention for many stakeholders in Michigan." Many nonprofits and concerned citizens stress the point that operators of high-volume wells are not required to report the composition of those fluids to the state until 60 days after the hydraulic fracturing event.

The often-repeated concern is that if a spill were to occur, responders would not be as well-prepared as they would have been if the fluid composition had been known beforehand, Wolske and Hoffman note.

Though groundwater contamination is often cited as a top concern, surface contamination from spills and improper disposal of waste fluids likely carries the greatest risk for harmful water-quality impacts, due to proximity to potable water resources, according to the geology/ hydrogeology report written by Brian Ellis, assistant professor in the Department of Civil and Environmental Engineering.

When a well is fracked, the fluid is injected into rock formations to create cracks and to prop them open. Of the total volume of hydraulic fracturing fluids injected into a well, amounts varying from 10 percent to 70 percent may return to the surface as "flowback water" after the pressure is reduced and gas or oil begin to flow toward the wellhead.

In Michigan high-volume hydraulically fractured wells, the average amount of flowback water returning to the surface is about 37 percent of injected volumes, according to the Ellis report.

The flowback water is highly saline and can contain elevated levels of heavy metals and naturally occurring radioactive elements, in addition to methane and the original chemical additives in the fracturing fluids. In Michigan, common hydraulic fracturing fluid additives include ethylene glycol, hydrochloric acid, isopropyl alcohol, methanol and ammonium persulfate, according to the Ellis report.

"However, since in Michigan all flowback is disposed of by deep-well injection and it is not allowed to sit in open pits, the risk of this type of contamination will be lower than in other states without such disposal opportunities and regulations," Ellis wrote.

On the topic of potential water contamination, the environment/ecology report notes that Michigan's dense, interconnected aquatic ecosystems (streams, rivers, lakes, inland and coastal wetlands) and the groundwater aquifers to which they are linked are of particular concern. The connectivity between surface and groundwater bodies "can lead to impacts distant from, as well as close to, drilling sites," according to the report by G. Allen Burton, professor in the School of Natural Resources and Environment and director of the U-M Water Center, and Knute Nadelhoffer, professor of ecology and evolutionary biology and director of the U-M Biological Station.

The potential migration of methane, the main component of natural gas, into groundwater reservoirs has also received a lot of attention lately.

But the probability of significant methane leakage associated with deep-shale drilling involving hydraulic fracturing in Michigan "is quite low provided that best practices are adhered to," according to the U-M report on hydraulic fracturing technologies written by John Wilson, a consultant to the U-M Energy Institute, and Johannes Schwank, professor of chemical engineering.

The greatest challenge to understanding the potential public health risks of hydraulic fracturing in Michigan is the lack of state-specific data, according to Niladri Basu, author of the public health technical report and a former faculty member at the U-M School of Public Health. While thousands of hydraulically fractured wells have been drilled in Michigan, the potential public health risks related to these facilities have been poorly documented, Basu wrote.

For example, while operators of high-volume fracking wells are required to disclose the contents of their hydraulic fracturing fluids, operators of the 12,000 or so low-volume wells in the state are not. "There needs to be much greater understanding of what chemicals are being used in every well, with information related to volumes, amounts, disposal plans, etc., made available," Basu wrote.

The U-M hydraulic fracturing study is expected to cost at least $600,000 and is being funded by U-M through its Graham Sustainability Institute, Energy Institute and Risk Science Center. State regulators, oil and gas industry representatives, staffers from environmental nonprofits, and peer reviewers provided input to the technical reports, and more than 100 public comments were considered.

In addition to the study authors mentioned above, the technical report authors include Roland Zullo, assistant research scientist, U-M Institute for Research on Labor, Employment and the Economy (economics report).

Technical reports: http://graham.umich.edu/knowledge/ia/hydraulic-fracturing/technical-reports

Source: University of Michigan

Offsetting global warming: Targeting solar geoengineering to minimize risk and inequality

Sunset in the Arctic. A new study at Harvard explores the feasibility of using cautious and targeted solar geoengineering to counter the loss of Arctic sea ice.

A new study suggests that solar geoengineering can be tailored to reduce inequality or to manage specific risks like the loss of Arctic sea ice. By tailoring geoengineering efforts by region and by need, a new model promises to maximize the effectiveness of solar radiation management while mitigating its potential side effects and risks.

Developed by a team of leading researchers, the study was published in the November issue of Nature Climate Change.

Solar geoengineering, the goal of which is to offset the global warming caused by greenhouse gases, involves reflecting sunlight back into space. By increasing the concentrations of aerosols in the stratosphere or by creating low-altitude marine clouds, the as-yet hypothetical solar geoengineering projects would scatter incoming solar heat away from Earth's surface.

Critics of geoengineering have long warned that such a global intervention would have unequal effects around the world and could result in unforeseen consequences. They argue that the potential gains may not be worth the risk.

Gordon McKay Professor of Applied Physics at the Harvard School of Engineering and Applied Sciences (SEAS) and Professor of Public Policy at Harvard Kennedy School. "Instead, we can be thoughtful about various tradeoffs to achieve more selective results, such as the trade-off between minimizing global climate changes and minimizing residual changes at the worst-off location."
The study -- developed in collaboration with Douglas G. MacMartin of the California Institute of Technology, Ken Caldeira of the Carnegie Institution for Science, and Ben Kravitz, formerly of Carnegie and now at the Department of Energy -- explores the feasibility of using solar geoengineering to counter the loss of Arctic sea ice.

"There has been a lot of loose talk about region-specific climate modification. By contrast, our research uses a more systematic approach to understand how geoengineering might be used to limit a specific impact. We found that tailored solar geoengineering might limit Arctic sea ice loss with several times less total solar shading than would be needed in a uniform case."

Generally speaking, greenhouse gases tend to suppress precipitation, and an offsetting reduction in the amount of sunlight absorbed by Earth would not restore this precipitation. Both greenhouse gases and aerosols affect the distribution of heat and rain on this planet, but they change the temperature and precipitation in different ways in different places. The researchers suggest that varying the amount of sunlight deflected away from Earth both regionally and seasonally could combat some of this problem.

"These results indicate that varying geoengineering efforts by region and over different periods of time could potentially improve the effectiveness of solar geoengineering and reduce climate impacts in at-risk areas," says co-author Ken Caldeira, Senior Scientist in the Department of Global Ecology at the Carnegie Institution for Science.

The researchers note that while their study used a state-of-the-art model, any real-world estimates of the possible impact of solar radiation management would need to take into account various uncertainties. Further, any interference in Earth's climate system, whether intentional or unintentional, is likely to produce unanticipated outcomes.

"While more work needs to be done, we have a strong model that indicates that solar geoengineering might be used in a far more nuanced manner than the uniform one-size-fits-all implementation that is often assumed. One might say that one need not think of it as a single global thermostat. This gives us hope that if we ever do need to implement engineered solutions to combat global warming, that we would do so with a bit more confidence and a great ability to test it and control it."


Source: Harvard University

Study shows no evidence of groundwater contamination from hydraulic fracturing

Hydraulic fracturing of shale formations to extract natural gas has no direct connection to reports of groundwater contamination, based on evidence reviewed in a study released recently by the Energy Institute at The University of Texas at Austin.

The study, released at the annual meeting of the American Association for the Advancement of Science (AAAS) in Vancouver, British Columbia, found that many problems ascribed to hydraulic fracturing are related to processes common to all oil and gas drilling operations, such as casing failures or poor cement jobs.

University researchers also concluded that many reports of contamination can be traced to above-ground spills or other mishandling of wastewater produced from shale gas drilling, rather than from hydraulic fracturing per se, said Charles "Chip" Groat, an Energy Institute associate director who led the project.

"These problems are not unique to hydraulic fracturing," he said.
The research team examined evidence contained in reports of groundwater contamination attributed to hydraulic fracturing in three prominent shale plays -- the Barnett Shale in North Texas; the Marcellus Shale in Pennsylvania, New York and portions of Appalachia; and the Haynesville Shale in western Louisiana and northeast Texas.

The report identifies regulations related to shale gas development and evaluates individual states' capacity to enforce existing regulations. In addition, university researchers analyzed public perceptions of hydraulic fracturing, as derived from popular media, scientific literature and online surveys.
"Our goal was to provide policymakers a foundation for developing sensible regulations that ensure responsible shale gas development," Groat said. "What we've tried to do is separate fact from fiction."
Faculty members from across The University of Texas at Austin campus participated in the research, which the Energy Institute funded. The Environmental Defense Fund also assisted in developing the scope of work and methodology for the study. To read the complete report, visit http://energy.utexas.edu/.

Groat said researchers will supplement the study with an examination of reports relating to atmospheric emissions and seismic activity attributed to hydraulic fracturing, which have emerged as significant issues of concern in recent months.

Hydraulic fracturing involves the high-pressure injection of water, sand and chemicals into a shale bed, which causes the rock to shatter, releasing natural gas. The practice has been in use for decades but has come under scrutiny in recent years from environmentalists and others who fear it poses a threat to public health.

Scientist offers better ways to engineer Earth's climate to prevent dangerous global warming

There may be better ways to engineer the planet's climate to prevent dangerous global warming than mimicking volcanoes, a University of Calgary climate scientist says in two new studies.

Releasing engineered nano-sized disks, or sulfuric acid in a condensable vapor above the Earth, are two novel approaches. These approaches offer advantages over simply putting sulfur dioxide gas into the atmosphere," says David Keith, a director in the Institute for Sustainable Energy, Environment and Economy and a Schulich School of Engineering professor.

Keith, a global leader in investigating this topic, says that geoengineering, or engineering the climate on a global scale, is an imperfect science.

"It cannot offset the risks that come from increased carbon dioxide in the atmosphere. If we don't halt man-made CO₂ emissions, no amount of climate engineering can eliminate the problems -- massive emissions reductions are still necessary."

Nevertheless, Keith believes that research on geoengineering technologies, their effectiveness and environmental impacts needs to be expanded.

"I think the stakes are simply too high at this point to think that ignorance is a good policy."

Keith suggests two novel geoengineering approaches -- 'levitating' engineered nano-particles, and the airborne release of sulfuric acid -- in two newly published studies. One study was authored by Keith alone, and the other with scientists in Canada, the U.S. and Switzerland.

Scientists investigating geoengineering have so far looked mainly at injecting sulfur dioxide into the upper atmosphere. This approach imitates the way volcanoes create sulfuric acid aerosols, or sulfates, that will reflect solar radiation back into space -- thereby cooling the planet's surface.

Keith says that sulfates are blunt instruments for climate engineering. It's very difficult to achieve the optimum distribution and size of the aerosols in the atmosphere to reflect the most solar radiation and get the maximum cooling benefit.

One advantage of using sulfates is that scientists have some understanding of their effects in the atmosphere because of emissions from volcanoes such as Mt. Pinatubo, he adds.

"A downside of both these new ideas is they would do something that nature has never seen before. It's easier to think of new ideas than to understand their effectiveness and environmental risks," says Keith.

In his study-published in the Proceedings of the National Academy of Sciences, Keith describes a new class of engineered nano-particles that might be used to offset global warming more efficiently, and with fewer negative side effects, than using sulfates.

According to Keith, the distribution of engineered nano-particles above the Earth could be more controlled and less likely to harm the planet's protective ozone layer.

Sulfates also have unwanted side-effects, ranging from reducing the electricity output from certain solar power systems, to speeding up the chemical process that breaks down the ozone layer.

Engineered nano-particles could be designed as thin disks and built with electric or magnetic materials that would enable them to be levitated or oriented in the atmosphere to reflect the most solar radiation.

It may also be possible to control the position of particles above the Earth. In theory, the particles might be engineered to drift toward Earth's poles, to reduce solar radiation in polar regions and counter the melting of ice that speeds up polar warming-known as the ice-albedo feedback.

"Such an ability might be relevant in the event that warming triggers rapid deglaciation," Keith's study says.

"Engineered nano-particles would first need to be tested in laboratories, with only short-lived particles initially deployed in the atmosphere so any effects could be easily reversible," says Keith.

Research would also be needed to determine whether such nano-particles could be effectively distributed, given the complex interplay of forces in the atmosphere, and how much cooling might be achieved at the planet's surface.

It is also unknown whether the amount of particles needed-about 1 trillion kilograms per year or 10 million tonnes over 10 years-could be manufactured and deployed at a reasonable cost.

However, Keith notes another study, which looked at the cost of putting natural sulfates into the stratosphere.

"You could manipulate the Earth's climate at large scale for a cost that's of the order of $1 billion a year. It sounds like a lot of money, but compared to the costs of managing other environmental problems or climate change, that is peanuts."

"This is not an argument to do it, only an indication that risk, not cost, will be the deciding issue," he adds.

In a separate new study published in the journal Geophysical Research Letters, Keith and international scientists describe another geoengineering approach that may also offer advantages over injecting sulfur dioxide gas.

Releasing sulfuric acid, or another condensable vapor, from an aircraft would give better control of particle size. The study says this would reflect more solar radiation back into space, while using fewer particles overall and reducing unwanted heating in the lower stratosphere.

The study included computer modeling that showed that the sulfuric acid would quickly condense in a plume, forming smaller particles that would last longer in the stratosphere and be more effective in reflecting solar radiation than the large sulfates formed from sulfur dioxide gas.

Keith stresses that whether geoengineering technology is ever used, it shouldn't be seen as a reason not to reduce man-made greenhouse gas emissions now accumulating in the atmosphere.

"Seat belts reduce the risk of being injured in accidents. But having a seat belt doesn't mean you should drive drunk at 100 miles an hour," he says.

Source: University of Calgary

Stop Emitting Carbon Dioxide, Or Geoengineering Could Be Only Hope For Earth's Climate, Experts Warn

A new report finds that unless future efforts to reduce greenhouse gas emissions are much more successful than they have been so far, additional action in the form of geoengineering will be necessary if we are to cool the planet. Credit: iStockphoto/Andrey Prokhorov

The future of the Earth could rest on potentially dangerous and unproven geoengineering technologies unless emissions of carbon dioxide can be greatly reduced, the latest Royal Society report has found.

The report (published September 1, 2009 by the Royal Society, the UK’s national academy of science) found that unless future efforts to reduce greenhouse gas emissions are much more successful than they have been so far, additional action in the form of geoengineering will be necessary if we are to cool the planet. Geoengineering technologies were found to be very likely to be technically possible and some were considered to be potentially useful to augment the continuing efforts to mitigate climate change by reducing emissions. However, the report identified major uncertainties regarding their effectiveness, costs and environmental impacts.

Professor John Shepherd, who chaired the Royal Society’s geoengineering study, said, “It is an unpalatable truth that unless we can succeed in greatly reducing CO₂emissions we are headed for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases. Our research found that some geoengineering techniques could have serious unintended and detrimental effects on many people and ecosystems - yet we are still failing to take the only action that will prevent us from having to rely on them. Geoengineering and its consequences are the price we may have to pay for failure to act on climate change.”

The report assesses the two main kinds of geoengineering techniques – Carbon Dioxide Removal (CDR) and Solar Radiation Management (SRM). CDR techniques address the root of the problem – rising CO₂ – and so have fewer uncertainties and risks, as they work to return the Earth to a more normal state. They are therefore considered preferable to SRM techniques, but none has yet been demonstrated to be effective at an affordable cost, with acceptable environmental impacts, and they only work to reduce temperatures over very long timescales.

SRM techniques act by reflecting the sun’s energy away from Earth, meaning they lower temperatures rapidly, but do not affect CO₂ levels. They therefore fail to address the wider effects of rising CO₂, such as ocean acidification, and would need to be deployed for a very long time. Although they are relatively cheap to deploy, there are considerable uncertainties about their regional consequences, and they only reduce some, but not all, of the effects of climate change, while possibly creating other problems. The report concludes that SRM techniques could be useful if a threshold is reached where action to reduce temperatures must be taken rapidly, but that they are not an alternative to emissions reductions or CDR techniques.

Professor Shepherd added, “None of the geoengineering technologies so far suggested is a magic bullet, and all have risks and uncertainties associated with them. It is essential that we strive to cut emissions now, but we must also face the very real possibility that we will fail. If “Plan B” is to be an option in the future, considerable research and development of the different methods, their environmental impacts and governance issues must be undertaken now. Used irresponsibly or without regard for possible side effects, geoengineering could have catastrophic consequences similar to those of climate change itself. We must ensure that a governance framework is in place to prevent this.”

Of the CDR techniques assessed, the following were considered to have most useful potential:

• CO₂ capture from ambient air – this would be the preferred method of geoengineering, as it effectively reverses the cause of climate change. At this stage no cost-effective methods have yet been demonstrated and much more research and development is needed.
• Enhanced weathering – this technique, which utilises naturally occurring reactions of CO₂ from the air with rocks and minerals, was identified as a prospective longer-term option. However more research is needed to find cost-effective methods and to understand the wider environmental implications.
• Land use and afforestation – the report found that land use management could and should play a small but significant role in reducing the growth of atmospheric CO2 concentrations. However the scope for applying this technique would be limited by land use conflicts, and all the competing demands for land must be considered when assessing the potential for afforestation and reforestation. Should temperatures rise to such a level where more rapid action needs to be taken, the following SRM techniques were considered to have most potential:
• Stratospheric aerosols – these were found to be feasible, and previous volcanic eruptions have effectively provided short-term preliminary case studies of the potential effectiveness of this method. The cost was assessed as likely to be relatively low and the timescale of action short. However, there are some serious questions over adverse effects, particularly depletion of stratospheric ozone.
• Space-based methods – these were considered to be a potential SRM technique for long-term use, if the major problems of implementation and maintenance could be solved. At present the techniques remain prohibitively expensive, complex and would be slow to implement.
• Cloud albedo approaches (eg. cloud ships) – the effects would be localised and the impacts on regional weather patterns and ocean currents are of considerable concern but are not well understood. The feasibility and effectiveness of the technique is uncertain. A great deal more research would be needed before this technique could be seriously considered.

The following techniques were considered to have lower potential:

• Biochar (CDR technique) – the report identified significant doubts relating to the potential scope, effectiveness and safety of this technique and recommended that substantial research would be required before it could be considered for eligibility for UN carbon credits.
• Ocean fertilisation (CDR technique) – the report found that this technique had not been proved to be effective and had high potential for unintended and undesirable ecological side effects.
• Surface albedo approaches (SRM technique, including white roof methods, reflective crops and desert reflectors) – these were found to be ineffective, expensive and, in some cases, likely to have serious impacts on local and regional weather patterns.

Source: The Royal Society

Geoengineering Could Slow Down Global Water Cycle

A schematic representation of various geoengineering and carbon storage proposals. Credit: Diagram by Kathleen Smith/LLNL

As fossil fuel emissions continue to climb, reducing the amount of sunlight hitting the Earth would definitely have a cooling effect on surface temperatures.

However, a new study from Lawrence Livermore National Laboratory, led by atmospheric scientist Govindasamy Bala, shows that this intentional manipulation of solar radiation also could lead to a less intense global water cycle. Decreasing surface temperatures through "geoengineering" also could mean less rainfall.

The reduction in sunlight can be accomplished by geoengineering schemes. There are two classes: the so-called "sunshade" geoengineering scheme, which would mitigate climate change by intentionally manipulating the solar radiation on the earth's surface; the other category removes atmospheric CO₂ and sequesters it into the terrestrial vegetation, oceans or deep geologic formations.

In the new climate modeling study, which appears in the May 27-30 early online edition of the Proceedings of the National Academy of Sciences, Bala and his colleagues Karl Taylor and Philip Duffy demonstrate that the sunshade geoengineering scheme could slow down the global water cycle.

The sunshade schemes include placing reflectors in space, injecting sulfate or other reflective particles into the stratosphere, or enhancing the reflectivity of clouds by injecting cloud condensation nuclei in the troposphere. When CO₂ is doubled as predicted in the future, a 2 percent reduction in sunlight is sufficient to counter the surface warming.

This new research investigated the sensitivity of the global mean precipitation to greenhouse and solar forcings separately to help understand the global water cycle in a geoengineered world.

While the surface temperature response is the same for CO₂ and solar forcings, the rainfall response can be very different.

"We found that while climate sensitivity can be the same for different forcing mechanisms, the hydrological sensitivity is very different," Bala said.

The global mean rainfall increased approximately 4 percent for a doubling of CO₂and decreases by 6 percent for a reduction in sunlight in his modeling study.

"Because the global water cycle is more sensitive to changes in solar radiation than to increases in CO₂, geoengineering could lead to a decline in the intensity of the global water cycle" Bala said.

A recent study showed that there was a substantial decrease in rainfall over land and a record decrease in runoff and discharge into the ocean following the eruption of Mount Pinatubo in 1991. The ash emitted from Pinatubo masked some of the sunlight reaching the earth and therefore decreased surface temperatures slightly, but it also slowed down the global hydrologic cycle.

"Any research in geoengineering should explore the response of different components of the climate system to forcing mechanisms," Bala said.

For instance, Bala said, sunshade geoengineering would not limit the amount of CO₂ emissions. CO₂ effects on ocean chemistry, specifically, could have harmful consequences for marine biota because of ocean acidification, which is not mitigated by geoengineering schemes.

"While geoengineering schemes would mitigate the surface warming, we still have to face the consequences of CO₂ emissions on marine life, agriculture and the water cycle," Bala said.

Source: DOE/Lawrence Livermore