Jets’ contrails contribute to heat-trapping high-level clouds

By Anne Danahy

February 21, 2013

UNIVERSITY PARK, Pa. -- Condensation trails that airplanes produce mean not only a white-streaked sky on some days, but an increase in the amount of high-level clouds and, by extension, warming temperatures, according to a Penn State researcher.

By comparing National Oceanic and Atmospheric Administration satellite images showing contrail occurrence with data from eastern U.S. stations that record sky-coverage for different levels in the atmosphere, Penn State Professor of Geography Andrew Carleton was able to confirm that contrails contribute to the occurrence of high-level clouds.

The results of the analysis that Carleton and several of his students completed will be published this spring in the international journal Climate Research.

To address the question of whether there is any relation between jet contrails and trends in sky coverage, the researchers plotted the spatial occurrence of contrails identified on the satellite images for two time periods: 1977-79 and 2000-02. Sky cover data on clouds occurring at different levels has been collected continuously at National Weather Service stations. The satellite contrail and surface-observed sky-cover data was overlaid and separated according to high versus low frequencies of contrails.

The researchers found that high frequencies of contrails didn’t equate to an increase in total cloud amount or an increase in low-lying clouds, but they did mean a significant increase in high-level cloudiness observed from the surface since about the mid-1960s.

“It suggests that contrails do influence the upward trend in the amount of high-level clouds over the last 50 years for the eastern one-third of the United States,” said Carleton, a faculty member in Penn State’s Earth and Environmental Systems Institute.

While Carleton wasn’t surprised by the results, he said establishing them is an important step in looking at what might be done to address the issue. It could be particularly important in upcoming decades as the potential for contrails to go from being regionally significant to more widespread becomes likely as air traffic continues to increase.

Contrails form when jet engines emit sooty particles and moisture into cold air high in the troposphere. Water vapor already present in the atmosphere collects and freezes around those particles, which are essentially the nuclei, and form linear ice crystal clouds. Contrails are prevalent in the Midwest, Northeast and Southeast of the United States, along with Western Europe and the North Atlantic. East and Southeast Asia could see growing impacts of contrails in the upcoming 20 to 30 years, as economies and air travel there continue to grow.

Carleton’s previous research found that contrails affect the climate near Earth’s surface by reducing the daily range of temperatures (the warmest point during the day minus the coolest temperature at night). He and David Travis, from the University of Wisconsin-Whitewater, undertook a base study on contrails and surface temperature conditions after the Sept. 11, 2001, terrorist attacks, when there were no commercial jets in the air for three days. They found that the lack of flights led to an increase in the range of temperatures for the United States in general, and sub-regions typically seeing the highest frequencies of contrails (the Midwest and Northeast). The researchers concluded that jet contrails contribute to reducing the near-surface air temperature range.

Persisting contrails present the greatest impact on climate because instead of dissipating relatively quickly they linger, trapping heat beneath them. While contrails do block the sun to some extent, when they persist they also spread and become thinner, which means they don’t reflect as much solar energy away while still trapping heat.

“The net effect tends to be to warm the earth’s surface, rather than to cool it,” Carleton said.

The new research finds that in addition to shrinking the temperature range, contrails contribute to high-level cloudiness, which can contribute to warming the atmosphere.

A next step is trying to predict where and when contrails will occur so, when needed, planes could be rerouted around those areas to head off further aggravating the contrail impact on climate. Carleton noted that this is similar to the short-term rerouting of planes that already happens with severe storms.

“These contrail outbreaks are, broadly speaking, similar in size to big summer storm events,” he said.

The work is supported by funding from the National Science Foundation.

Betelgeuse Blows Out a Monstrous Arc of Gas Nearly As Big As Our Solar System

文章 Articles

China’s geoengineering plans dismissed as “fantasy”

Beth Walker

Olivia Boyd

11.04.2013

comments

0

The authorities are increasing their cloud-seeding ambitions in response to drought, but many experts are sceptical about the benefits

China has a long history of "rainmaking", but experts are sharply divided on the merits. (Image by baike.baidu.com)

 

Airplanes loaded with cloud-seeding chemicals swept across southwest China early last month in a bid to bring rain to the drought-parched region. Tens of thousands of rockets and battalions of cannons stood poised to ambush stray clouds that might pass unwittingly into view.

By mid March a light, sporadic drizzle over Yunnan province brought welcome relief to farmers and residents struggling into a fourth consecutive year of severe drought. Local newspapers heralded the rains as the province’s first successful large scale cloud-seeding operations of the year.

This was the latest episode in China’s attempts to control the weather.

The water-starved country already has the world’s largest weather engineering programmes, and these look set to grow. In February, China’s top economic planner, the National Development and Reform Commission, announced plans to step up cloud-seeding and other weather modification techniques to tackle drought and boost agriculture.

Cloud-seeding is the oldest and most common weather modification technology, and often a resort during drought. It involves injecting clouds with frozen carbon dioxide (dry ice) or silver iodide, using military aircraft, cannons or rockets, to speed up the production of rain.

China’s bid to use cloud-seeding to guarantee blue skies during the 2008 Beijing Olympics caught global attention. But the country’s history of “rainmaking” stretches back into the distant past. Marco Polo reportedly returned to Europe from Cathay with an “explosive yellow powder” – and tales of how the Chinese used it to trigger rain, historian James R Fleming points out in his book Fixing The Sky.

Today, China spends US$100 million a year on operations to make rain, prevent hailstorms, contribute to fire fighting and counteract dust storms in almost every province.

It’s a figure expected to grow. "Weather modification technology is crucial to China," Zheng Guoguang, head of the China Meteorological Administration, told China Daily in 2012. During China's 12th Five-Year plan period "our goal is to reduce losses caused by weather disasters from 3% of GDP last year to 1% by the end of the period."

Doubts about effectiveness
China is not the only country looking for technological fixes to water scarcity. The popularity of cloud-seeding has rocketed over the past decade, as governments, companies and scientists turn to large-scale interventions in our climate systems – known as geoengineering – as a potential fix for water shortages and global warming.

In the US, cloud-seeding is used to boost rainfall during spring planting, suppress hail, increase snowpack in the Rocky Mountains and divert and weaken hurricanes. Scientists working for the Abu Dhabi government claimed to have created more than 50 rainstorms in Al Ain in July and August of 2010, the peak of summer. Indonesia recently said it had used cloud-seeding to prevent further flooding in its inundated capital Jakarta.Iraq, Yemen, India and Mexico all have their own programmes.

“Worldwide more than 40 or 50 countries are doing cloud-seeding,” says Roelof Bruintjes one of the world's leading experts on weather modification at the US National Center for Atmospheric Research who has helped many countries design and improve weather modification programmes, including China.

“With so many countries doing this, getting the science right is important.”

China’s false hopes on geoengineering
Though a prominent advocate of weather modification, Bruintjes is critical of China’s methods. Despite the wishful thinking of policymakers, cloud-seeding is “not a drought busting tool”, he says, pointing out that drought tends to mean less cloud – and without cloud, you can’t cloud-seed. Such techniques should be used as a long-term water management tool rather than a quick fix, he says.

Paul Sayers, a water expert at the University of Oxford who is advising the Chinese government on drought planning, also dismisses cloud-seeding as a solution to drought, arguing the authorities need to get a better balance between supply and demand management. “Drought plans can’t just be about infrastructure – desalination, cloud-seeding – China needs to think about drought in a more strategic way.” A start would be to find a way of prioritising water allocations during drought to avoid irreversible environmental damage, he says.

Experts are in fact sharply divided on the efficacy of cloud-seeding. TheChina Meteorological Administration claims its weather manipulations helped to release 490 billion tonnes of rain – about 12 times the water storage of the Three Gorges Project – between 2002 and 2012. But many are sceptical about such lofty claims, as well as China’s recent noises about more ambitious programmes.

“My first impression is that it’s very much more of a public relations effort than it might be a technically sound proposition,” says Fleming, who is professor of science, technology and society at Colby University in Maine. Being seen to do something about China’s worsening drought at least demonstrates an attempt to fix the problem, even if it achieves little.

As the world invests more in geoengineering, China is also likely to want to stay at the front of the pack, he says: “If China is becoming a world leader economically and in some ways militarily, they’re going to have to position themselves as a player in this field, even if from my point of view it’s a slight fantasy.”

Does it work?
The danger, Fleming argues, is that a focus on weather manipulation distracts from the lifestyle changes that can really make a difference to our environment. The biggest impact on the Beijing Olympics came not from the much-hyped “cocktail of artillery shell ordinance” used to bust up clouds, he says, but lower-key measures to slow down traffic into the city, which reduced hydrocarbons and helped clear the air, compounded by a “fortuitous weather pattern”.

This gets to the heart of the problem with evaluating cloud-seeding, namely the difficulty proving cause and effect. Weather is complex, shifting and difficult to understand – crediting shell fire for subsequent rain is easy enough in political rhetoric, but harder to stand up scientifically.

Some of the research that has been done strikes a sceptical tone. In 2003, the US National Research Council published a study that questioned the effectiveness of cloud-seeding and the extent of impacts outside of local areas. The report called for greater research into practices for understanding and improving cloud-seeding impacts.

To complicate things further, rising levels of pollution in the atmosphere could reduce the effectiveness of cloud-seeding, says Bruintjes. His research on inadvertent weather modification, including the effects of smoke and pollution on clouds and rainfall, suggests that what works in an unpolluted region may not in a highly polluted one.

He says more research is urgently needed in China, where the approach has been chaotic and unscientific:“They have made some claims but there is no evaluation available that can substantiate their claims," he says. China has started to invest more in upgrading technology and evaluation methods, adds Bruintjes, but results will be slow to show.

Research is costly, admits Bruintjes, but if you can get 10-15% of water out of cloud, it’s cost-effective – “five to 15 times cheaper” than any water-saving alternative, such as building reservoirs, desalination plants or water-transfer programmes.

Fears of local and regional conflict
Concerns stretch beyond efficacy and cost, however. Fleming points out that commerce is playing a driving role in weather modification. His studies of dry areas of the US show funding for rainfall enhancement is coming not from the government, but from water companies, irrigation companies and hydropower companies.

Officials in China have also talked about providing cloud-seeding as a service to the private sector. The prospect of companies paying for rain to fall in one area – potentially meaning it won’t fall somewhere else – will inevitably raise knotty questions about water rights and public access to resources.

Some commentators are also fearful that growing use of weather modification could lead to conflict both within and between states.

Its development is already closely linked with military espionage. During the Cold War, US scientists debated weather modification as one way to destroy Soviet agricultural harvests and incite internal dissent. The US military used cloud-seeding in the Vietnam War to disrupt transport of military supplies along the Ho Chi Minh, a move it's claimed triggered catastrophic flooding and widespread starvation.

James Lee, professor at the American University, Washington and author ofClimate Change and Armed Conflict, has even suggested the US military is investing in cloud-seeding as an excuse for developing drones. Almost inevitably, Lee fears the widespread use of weather modification could trigger resource conflicts: “There are so many countries involved in this that I think at some time, one country is going to say to the other ‘hey, you’re stealing our rain’.”

The History of Weather Control

I would like to extend an invitation to everyone in this community to please browse, share, and fact check an interactive javascript timeline based on weather modification andgeoengineering.
As we all know there is not a definitive history of weather control, therefore I have put much effort into creating one.  This page will grow over time, with many additions/corrections.
Each slide has an image, with reference links beneath the image.  
Please send me any links to other timelines and reference material that can help me flesh this story out.  

The History of Weather Control
http://www.terraforminginc.com/weather-control/

Thank you for your time.

Jim Lee
http://www.terraforminginc.com/
http://www.climateviewer.com/

Geoengineering Research Needs Better Guidelines, Climate Change Experts Say

Posted: 03/17/2013 2:14 pm EDT

1

GET GREEN ALERTS:

SIGN UP

FOLLOW:

Climate Change, Climate Change Geoengineering, Climate Change Geoengineering Research,Climate Change Research, Geoengineering, Geoengineering Climate Change, Geoengineering Climate Change Research, Geoengineering Research, Green News

From Climate Central's Lauren Morello:

With no clear rules to guide new research, scientists are shying away from examining whether geoengineering technologies can effectively cool the planet, and at what cost.

That’s the warning put forth by a pair of climate change experts in an essay published Thursday in the journal Science.

“This deadlock poses real threats to sound management of climate risk,” writeHarvard University climate scientist David Keith and UCLA environmental law expert Edward Parson. “Geoengineering may be needed to limit severe future risks, so informed policy judgments require research on its efficacy and risks."

Without that research, the world could face “unrefined, untested and excessively risky approaches” if climate change intensifies to the point that governments consider fighting it with geoengineering approaches, Parson and Keith said.

The researchers, who say the global debate over geoengineering is increasingly polarized, recommend that governments begin coordinating small-scale geoengineering research and block, at least for now, large-scale experiments.

They are not the first experts to recommend more geoengineering research. Over the past several years, the Bipartisan Policy Center, the U.K. Royal Society, the U.S. National Academy of Sciences, the House Science, Space and Technology Committee, the American Geophysical Union and the Government Accountability Office have all called for more study to determine the efficacy and drawbacks of various proposed geoengineering techniques.

Parson and Keith zero in on one category of techniques to engineer a cooler planet — those that aim to reduce the amount of incoming sunlight that reaches Earth, which have drawn significant attention and controversy.

And unlike many earlier reports calling for geoengineering research, theirs attempts to define the size and scope of “large” and “small” experiments and lay out concrete steps governments and scientists should take to regulate the field.

“There is an increasing crystallization of opposing views and in the specific groups that have looked at this,” Parson said, “which kind of makes sense because of the natural tension that you feel when you look at these technologies: ‘Oh my goodness, we could really need something like this because we’re doing such a poor job at managing the primary problem, which is climate change. But oh my goodness, (geoengineering techniques) hold so many perils themselves.’”

But that has not stopped what Parson and Keith deem “rogue” experimentation, including an episode last year in British Columbia, Canada. An American businessman arranged to dump about 100 tons of iron sulfate into the Pacific Ocean in July in the hope of kickstarting a massive plankton bloom that would draw down carbon dioxide from the atmosphere.

Researchers who study the ocean have warned that such experiments could have unknown, potentially harmful effects on marine ecosystems. Those concerns helped drive the U.N. Convention on Biodiversity and the London Convention, which regulates dumping of wastes into the ocean, to prohibit for-profit plans to fertilize plankton blooms with iron.

But despite those bans, when the American businessman Russ George undertook his experiment last summer near the islands of Haida Gwaii, the Canadian government was caught unaware.

And Parson and Keith argue the experiment, though ill-conceived, did not actually violate international law.

“The Haida case is a very good example of what you might fairly characterize as an experiment without controls, run without scientific organization,” Keith said. “We need the ability to regulate these things.”

He and Parson argue that governments should begin informal coordination to oversee small-scale field experiments that could help scientists understand how the atmosphere would respond to geoengineering — without having any significant effects on local climate conditions.

The category might include a small experiment to examine whether injecting sulfur compounds into the stratosphere destroys ozone molecules, or how spraying tiny particles of sea salt into the atmosphere affects cloud formation.

At the other end of the scale, Parson and Keith call for a government moratorium on experiments large enough to have a noticeable effect on regional or global climate conditions.

And there is little advantage to experiments that fall between those two extremes, they say.

“What I hope we are contributing is pointing out some quite effective things that cold be accomplished very simply and very quickly,” Keith said. “The experiments that could teach you a lot are very small, small compared to (the atmospheric effect of) things like trans-Atlantic airport flights.”

And a moratorium on large-scale experimentation could help allay the fears of people who worry that any research could make the actual use of geoengineering techniques a foregone conclusion.

Most importantly, both researchers said, studying geoengineering does not reduce the need for the world to cuts its greenhouse gas emissions, because geoengineering is not a long-term solution to climate change.

Their overall approach is sound, said Katharine Ricke, a postdoctoral fellow at the Carnegie Institution for Science who has published several studies evaluating different aspects of geoengineering. Her recent research suggests that economic incentives created by deploying geoengineering would drive governments to form small, exclusive coalitions, because the physical impact of geoengineering will vary widely around the globe.

"Every additional partner you bring in requires you to compromise on the setting of the global thermostat," Ricke said.

With that in mind, she said, "it's reasonable to assume that fostering international cooperation and inclusiveness and transparency in geoengineering research can probably only make it more likely that any implementation (of geoengineering) would be cooperative and inclusive and transparent."

Contact Us University of California-San Diego 9500 Gilman Drive La Jolla CA 92093-0532 USA Tel: 1-858-534-0000 Fax: 1-858-534-0000 Russell Group Research Topics Publications Field Projects Research Group Opportunties Courses Contact E-PEACE Eastern Pacific Emitted Aerosol Cloud Experiment PI: Lynn M. Russell; Lead Institution: University of California San Diego (UCSD) CoPIs and Collaborating Institutions: John H. Seinfeld, California Institute of Technology (CIT) Bruce Albrecht, University of Miami (UM) Armin Sorooshian, University of Arizona (UA) Intellectual Merit Particles in the atmosphere play a key role in cloud formation, acting as nuclei for water droplets. Clouds play an important role in absorbing and reflecting heat, hence they can potentially mitigate or exacerbate global warming. Aerosol-cloud radiative interactions are widely held to be the largest single source of uncertainty in climate model projections of future climate change due to increasing anthropogenic emissions (IPCC, 2007). The underlying causes of this uncertainty among modeled predictions of climate are the gaps in our fundamental understanding of cloud processes. There has been significant progress with both observations and models on these important questions. However, while the qualitative aspects of the Twomey, Albrecht, and Ackerman indirect effects of aerosols on clouds are well known, the quantitative representation of these processes is nontrivial and limits our ability to represent them in global climate models (GCMs), resulting in the largest uncertainties in predictions of future climate. Given the timeliness of these questions for advancing GCMs, it is essential to address the unanswered questions in cloud dynamical response to aerosol perturbations. Our proposed approach is a targeted aircraft campaign with embedded modeling studies to inform the experiment planning and to facilitate the interpretation of the results. The study will use the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft in July 2011 off the coast of Monterey, California, with a full payload of instruments to measure particle and cloud number, mass and composition distributions. As part of this project, we propose to expand the scope of a meteorology-focused ONR aircraft-based study of marine stratocumulus with three novel and important additional, climate-focused studies: (1) Controlled release and atmospheric distribution of three different size ranges of particles in flight (Albrecht) and on or by a dedicated ship (Russell) (2) Large Eddy Simulations (LES, Seinfeld) and Aerosol-Cloud Parcel (ACP, Russell) modeling studies constrained by the observations to test our ability to quantitatively predict the dynamical response to increases in particle concentrations in the natural atmosphere (3) Satellite analyses (Sorooshian) of marine stratocumulus to constrain the radiative properties of the natural, perturbed, and regional cloud systems Russell, Seinfeld, Albrecht, and Sorooshian bring important expertise in the state-of-the-art of these techniques to the proposed collaboration, and their commitment to working collaboratively on this project will enable advances in understanding cloud responses to particles. Broader Impacts The broader scientific impacts of the proposed research will be the improved understanding of fundamental aerosol-cloud processes that can be incorporated in global climate models to better inform decision makers. The broader educational impacts of the proposed research will be realized through: (1) Promotion of teaching, training and learning through development and piloting of an informal science education program targeting an underserved audience (2) Broadened participation of underrepresented groups Ð in this case, retired and elderly people Ð in research as well as in outreach (3) Enhancement of infrastructure for teaching through partnerships with an established educational organization (Osher Lifelong Learning Institute) (4) Broad dissemination of results through presentations, peer-reviewed publications and via the web (5) Societal benefits in terms of improved understanding of climate science and the related ethical issues Figure: The planned ship path for a ship speed of 12 m s-1 is shown on the first (bottom) layer of the horizontal grid. The second (middle) layer shows the resulting spatial distribution of CN in a 300 m deep boundary layer (based on our simple Gaussian puff dispersion model and transverse wind speed of 5 m s-1with blue region indicating <250 cm-3 and red region indicating >1000 cm-3). The third (top) layer shows the associated changes in the relative CDN inferred from the fraction of ship-emitted CN that are estimated to be CCN (with gray region indicating <100 cm-3 and white region indicating >500 cm-3). Overlying the CDN contours of the third (top) layer are the planned Twin Otter flights for sampling in the cloud, including comparable time in the track and the background concentrations. The modeled ship emissions of 1016 s-1are at the low end of previous observations [Hobbs et al., 2000; Frick and Hoppel, 2000]. Test Cruise A one-day test cruise was proposed and approved on the R/V Sproul; this cruise was carried out on 23 February 2011.

World cools on global warming as green fatigue sets in

Worldwide concerns about climate change have dropped dramatically since 2009

SAM MASTERS

 

 

WEDNESDAY 27 FEBRUARY 2013

 

 

inShare3

 

PRINT

A A A

EMAIL

Related articles

• Green is great - while you're rich
• Nature Studies by Michael McCarthy: What this pyramid says about us and climate change
• Little time left to halt warming
• Crunch time for climate deal talks in Durban
• We are losing climate change race, says Davey

Suggested Topics

• Financial Crisis
• Nature
• Global Warming
• Diplomacy
• Investment
• Energy
• Global Politics
• Industrial Countries
• Greenpeace
• Climate

Public concern about environmental issues including climate change has slumped to a 20-year low since the financial crisis, a global study reveals.

Fewer people now consider issues such as CO2 emissions, air and water pollution, animal species loss, and water shortages to be “very serious” than at any time in the last two decades, according to the poll of 22,812 people in 22 countries including Britain and the US.

Despite years of studies showing the impact of global warming on the planet, only 49 per cent of people now consider climate change a very serious issue – far fewer than at the beginning of the worldwide financial crisis in 2009.

Worries about climate change first dropped in industrialised nations but they have now also fallen in developing economies including Brazil and China, according to the survey by GlobeScan Radar.

The declining interest in climate change comes amid a backlash against costly green energy investments in an age of austerity. David Nussbaum, head of WWF UK, said “sustained pressure” was required from political leaders to combat climate change. He said it was only when “real indicators” of climate change came, such as floods and droughts, that public perceptions changed.

He told The Independent: “Of course people’s concerns about climate change changed in 2009 when economic pressures were rising… [But] the problems haven’t gone away… There are longer-term concerns that may not seem imminent that are extremely serious. A skilled political leader has got to grapple with how you act and respond to the immediate pressure people feel while helping [to take] account of the wider concerns and interests.”

Campaigners said the “perceived seriousness” of climate change had also fallen sharply since the unsuccessful UN Climate Change Summit in Copenhagen in December 2009. The summit ended in what was described as “confusion, disagreement and disarray” as political leaders failed to agree a legally binding deal to curb greenhouse gas emissions.

Graham Thompson, a spokesman for Greenpeace, said: “The public can see that the response of our politicians is completely inadequate to the threat scientists have revealed, and that dissonance is reflected in these polls.”

Doug Miller, chairman of GlobeScan, said: “Evidence of environmental damage is stronger than ever, but our data shows that economic crisis and a lack of political leadership mean that the public are starting to tune out.”

The Department of Energy and Climate Change reiterated the view of Ed Davey, Climate Change Secretary, that “the basic physics of climate change is irrefutable”.

The GlobeScan survey found that water pollution is viewed as the most serious environment problem worldwide with 58 per cent of people polled saying it represents a very serious concern.

 

 

inShare3