Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U of C scientist offers better ways to engineer Earth's climate to prevent dangerous global warming

07.09.2010
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 sulphuric acid in a condensable vapour above the Earth, are two novel approaches. These approaches offer advantages over simply putting sulphur 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 sulphuric 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 sulphur dioxide into the upper atmosphere. This approach imitates the way volcanoes create sulphuric acid aerosols, or sulphates, that will reflect solar radiation back into space – thereby cooling the planet's surface.

Keith says that sulphates 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 sulphates 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, a top-ranked international science journal–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 sulphates.

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.

Sulphates 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 sulphates 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 sulphur dioxide gas.

Releasing sulphuric acid, or another condensable vapour, 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 sulphuric 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 sulphates formed from sulphur 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.

Hollie Roberts | EurekAlert!
Further information:
http://www.ucalgary.ca

More articles from Earth Sciences:

nachricht A promising target in the quest for a 1-million-year-old Antarctic ice core
24.05.2018 | University of Washington

nachricht Tropical Peat Swamps: Restoration of Endangered Carbon Reservoirs
24.05.2018 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>