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Category — Geoengineering

Cutting emissions is ‘perfect option’

Tim Radford


Out of this world: an artist’s impression of a solar probe approaching the sun. Image: NASA/Johns Hopkins University via Wikimedia Commons

New research supports findings that the best way to limit global warming is simply by ending the use of fossil fuels, rather than ambitious climate engineering projects to reduce the sun’s effects

There is no alternative. To limit global warming and contain climate change, societies have no real option but to reduce emissions of carbon dioxide into the atmosphere, according to new research. There might be additional useful steps that nations could take, but nothing will be as effective as simply not burning fossil fuels.

Daniela Cusack, a geographer at the University of California Los Angeles, and colleagues report in the journal Frontiers of Ecology and Environment that they looked at all the options and came to the conclusion that abstinence would always be a better answer than such measures as putting giant mirrors in space to reflect sunlight, or multiplying the clouds to block the sun’s rays

“We found that climate engineering doesn’t offer a perfect option,” she said.“The perfect option is reducing emissions. We have to cut down the amount of emissions we’re putting into the atmosphere if, in the future, we want to have anything like the Earth we have now.” [Read more →]

June 6, 2014   1 Comment

Geo-engineering ‘could mean more heat’

Tim Radford


Another way to cooling: Removing trees from snowy slopes would increase reflectivity. Image: Thomas Maier via Wikimedia Commons

Finding a technology that would let us counteract the effects of climate change is a cherished dream. But if there is a cure, it could be worse than the disease, scientists say.

The geo-engineers just cannot win, it seems. First, scientists demonstrated that ambitious plans to cool the planet by dimming solar radiation could have unintended and unwelcome consequences. And now they have shown something even more alarming: any programme to block the sunlight could precipitate even more dramatic global warming once it stopped, according to Environmental Research Letters.

Geo-engineering as a fallback strategy has been on the climate science agenda for decades. Almost all climate researchers argue, and have argued for 30 years, that the most effective response to global warming and the threat of climate change is a drastic reduction in the use of fossil fuel, everywhere on the planet.

Although many governments have agreed, and have even introduced attempts to control greenhouse gas emissions, levels of carbon dioxide and other greenhouse gases keep rising.

So researchers have suggested other possible solutions: “artificial trees” to absorb atmospheric carbon dioxide; the fertilisation of the oceans to accelerate algal photosynthesis; and even the injection of sulphate particles into the stratosphere to block the incoming sunlight. Such things happen naturally, during occasional violent volcanic eruptions, and global cooling has been observed to follow.

This last deliberate technological response might create other kinds of unwelcome climate change, among which would be an alarming change in rainfall patterns, other scientists have argued.

But now Kelly McCusker of the University of Washington in the US and colleagues have proposed yet another reason for limiting discharges into the upper atmosphere. Whatever benefits might follow the technique known as solar radiation management or SRM would be wiped out once the management stopped. [Read more →]

February 23, 2014   No Comments

Green roofs effective for cities’ heat problems

Tim Radford


A hot day in Beijing’s Tiananmen Square: Cities are usually hotter than the countryside. Image: Tactesh882 via Wikimedia Commons

Climate change aside, cities tend to be warmer than the surrounding ciuntryside. Now researchers in the US have found ways that may lessen the effects of both problems.

Even without global warming, atmospheric temperatures are likely to rise later in the century: the expansion of the cities will see to that.

Climate scientists and meteorologists long ago recognised the “heat island” effect created by the cities, and made sure routine measurements were not distorted by urban sprawl. But Matei Georgescu of Arizona State University and colleagues think that as populations grow, and cities begin to spread, temperatures will rise anyway.

So, they report in the Proceedings of the National Academy of Sciences, they have tested a few strategies to mitigate the rise of city temperatures and perhaps at the same time turn down the rate of rise in greenhouse temperatures as well.

The argument goes like this: roofs, paved roads, pipes, wiring, traffic, central heating and air conditioning, industry and commerce and other such urban trappings could raise temperatures by 1°C to 2°C.

And cities are certain to expand: the population of the US is expected to grow to somewhere between 422 million to 690 million by 2050, with up to 260,000 square kilometers of land newly covered by roofs and roads. [Read more →]

February 15, 2014   No Comments

Few would welcome geo-engineering

Tim Radford


Simplest is often best: Biochar, made from vegetable matter, arouses fewer objections. Image: K.salo.85 via Wikimedia Commons

Trying to avert dangerously high global temperatures by modifying the climate – geo-engineering – may or may not be possible. It certainly won’t be popular, researchers say.

Geo-engineering – the frustrated climate scientist’s last-ditch solution to global warming – is not likely to be a very popular choice. Members of the public have “a negative view” of deliberate large-scale manipulation of the environment to counteract climate change, according to new research inNature Climate Change.

Geo-engineering has been repeatedly proposed as a response to the steady build-up of carbon dioxide in the atmosphere, and increasingly cited as a potential necessity as global emissions from fossil fuels have continued to increase. If political action fails, some scientists reason, then perhaps technology could stop global average temperatures from getting too high.

Among these options is the injection of aerosols into the stratosphere to block or dim the sunlight, or the release of reflecting devices in Earth orbit to actually reflect sunlight away from the planet, on the principle that if you can’t turn down the atmospheric temperature, you could at least put up a sunscreen to cool the planet a little.

Such ideas have failed to find universal favour in the scientific community, if only because such action could seriously upset rainfall patterns and trigger disaster in the arid parts of Africa. [Read more →]

January 17, 2014   No Comments

Reducing sunlight ‘will not cool Earth’

Tim Radford


Monsoon in Mumbai: Geo-engineering would risk disturbing weather systems. Image: w:user:PlaneMad via Wikimedia Commons

The beguiling idea that we can moderate global warming by engineering the atmosphere has been given a rebuff by two scientists who found the attempt could disrupt rainfall patterns.

Two German scientists have just confirmed that you can’t balance the Earth’s rising temperatures by simply toning down the sunlight. It may do something disconcerting to the patterns of global rainfall.

Earlier this year a US-led group of scientists ran sophisticated climate models of a geo-engineered world and proposed the same thing. Now Axel Kleidon and Maik Renner of the Max Planck Institute for Biogeochemistry in Jena, Germany, have used a different theoretical approach to confirm the conclusion, and explain why it would be a bad idea.

The argument for geo-engineering goes like this: the world is getting inexorably warmer, governments show no sign of drastically reducing greenhouse gas emissions, so why not control the planetary thermostat by finding a way to filter, block, absorb or reflect some of the sunlight hitting the Earth?

Such things can be done by pumping soot or aerosols into the stratosphere to dim the skies a fraction, or even floating mirrors in Earth orbit to reflect some of the sunlight back into space.

Either way, the result is the same: you have global temperature control, tuned perhaps to the average at the beginning of the last century, and you can then go on burning as much petrol or coal as you like.

But now the two biogeochemists at Jena report in the journal Earth System Dynamics that they used a simple energy balance model to show that the world doesn’t work like that. Water simply doesn’t respond to atmospheric heat and solar radiation in the same way. [Read more →]

December 7, 2013   No Comments

Geo-engineering ‘could upset rainfall’

Tim Radford


The Asian monsoon, which ensures a harvest for hundreds of millions, could be at risk. Image: Yann via Wikimedia Commons

Geo-engineering may be able to lower global temperatures but could be damaging to seasonal rainfall patterns, a study says.

Geo-engineering – the confident technocrat’s last resort solution to catastrophic climate change – could create damaging conditions of its own, according to new research.

Simone Tilmes of the National Center for Atmospheric Research in Boulder, Colorado, in the US and an international team of colleagues report in Geophysical Research Letters: Atmospheres that at least one deliberate technological strategy to limit global warming could reduce seasonal rainfall, including the monsoons of Asia that provide a lifeline to hundreds of millions.

Senior scientists have in the last decade tentatively considered technological responses to climate change on the basis that economies, politicians and consumers show no sign of making the dramatic reductions in fossil fuel use that would cut the greenhouse gas emissions that fuel global warming.

Among these responses is a relatively simple one. If greenhouse gases go on increasing, then more solar heat will be trapped in the atmosphere. So, the world should think of a way to reduce solar radiationinstead: spray sulphate particles into the stratosphere to block incoming sunlight, or even place arrays of mirrors into orbit to reflect a proportion of the sunlight away from the Earth.

So the scientists used 12 different climate models to simulate various possible futures, including one based on historical factors in which carbon dioxide did not just double, but reached four times the levels in the atmosphere during the American Revolution, and the Napoleonic wars that ravaged Europe at the dawn of the Industrial Revolution.

They found – not surprisingly – that a greenhouse world would be matched by a significant increase in rainfall in many places, along with prolonged droughts in others. That would happen because more warmth means more evaporation, greater saturation of the atmosphere and consequently more precipitation. [Read more →]

December 1, 2013   No Comments

Russia urges IPCC report to include geoengineering

Russia Urges IPCC Report to Include Geoengineering (via Climate Central)

By Martin Lukacs, The Guardian Russia is pushing for this week’s landmark U.N. climate science report to include support for controversial technologies to geoengineer the planet’s climate, according to documents obtained by the Guardian. As climate…

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September 24, 2013   No Comments

James Lovelock: The Vanishing Face of Gaia

Corporate Knights presents Dr. James Lovelock, originator of The Gaia Hypothesis (also known as Gaia Theory), discussing the need for human adaptation and survival in a coming era of massive environmental change due to global heating. Here Dr. Lovelock lectures based on his book, "The Vanishing Face of Gaia."





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November 19, 2012   No Comments