Poll of international experts by The Independent reveals consensus that CO2 cuts have failed – and their growing support for technological intervention
By Steve Connor, Science Editor and Chris Green
The Independent, Friday, 2 January 2009
Related Articles
An emergency "Plan B" using the latest technology is needed to save the world from dangerous climate change, according to a poll of leading scientists carried out by The Independent. The collective international failure to curb the growing emissions of carbon dioxide (CO2) in the atmosphere has meant that an alternative to merely curbing emissions may become necessary.
The plan would involve highly controversial proposals to lower global temperatures artificially through daringly ambitious schemes that either reduce sunlight levels by man-made means or take CO2 out of the air. This "geoengineering" approach – including schemes such as fertilising the oceans with iron to stimulate algal blooms – would have been dismissed as a distraction a few years ago but is now being seen by the majority of scientists we surveyed as a viable emergency backup plan that could save the planet from the worst effects of climate change, at least until deep cuts are made in CO2 emissions.
What has worried many of the experts, who include recognised authorities from the world's leading universities and research institutes, as well as a Nobel Laureate, is the failure to curb global greenhouse gas emissions through international agreements, namely the Kyoto Treaty, and recent studies indicating that the Earth's natural carbon "sinks" are becoming less efficient at absorbing man-made CO2 from the atmosphere.
Levels of CO2 have continued to increase during the past decade since the treaty was agreed and they are now rising faster than even the worst-case scenarios from the Intergovernmental Panel on Climate Change, a United Nations body. In the meantime the natural absorption of CO2 by the world's forests and oceans has decreased significantly. Most of the scientists we polled agreed that the failure to curb emissions of CO2, which are increasing at a rate of 1 per cent a year, has created the need for an emergency "plan B" involving research, development and possible implementation of a worldwide geoengineering strategy.
Just over half – 54 per cent – of the 80 international specialists in climate science who took part in our survey agreed that the situation is now so dire that we need a backup plan that involves the artificial manipulation of the global climate to counter the effects of man-made emissions of greenhouse gases. About 35 per cent of respondents disagreed with the need for a "plan B", arguing that it would distract from the main objective of cutting CO2 emissions, with the remaining 11 per cent saying that they did not know whether a geoengineering strategy is needed or not.
Almost everyone who thought that geoengineering should be studied as a possible plan B said that it must not be seen as an alternative to international agreements on cutting carbon emissions but something that runs in parallel to binding treaties in case climate change runs out of control and there an urgent need to cool the planet quickly.
Geoengineering was dismissed as a distraction a few years ago but it has recently become a serious topic of research. Next summer, for example, the Royal Society, in London, is due to publish a report on the subject, led by Professor John Shepherd of the National Oceanography Centre at Southampton University. Professor Shepherd was one of the scientists who said that a plan B was needed because he was now less optimistic about the prospects of curbing CO2 levels since Kyoto was agreed, and less optimistic about the ability of the Earth's climate system to cope with the expected CO2 increases. "Geoengineering options... must not be allowed to detract from efforts to reduce CO2 emissions directly," said Professor Shepherd, who studies the interaction between the climate and oceans. In answer to the question of whether scientists were more optimistic or less optimistic about the ability of the climate system to cope with increases in man-made CO2 without dangerous climate change, just one out of the 80 respondents to our survey was more optimistic, 72 per cent were less optimistic, and 23 per cent felt about the same.
Professor James Lovelock, a geo-scientist and author of the Gaia hypothesis, in which the Earth is a quasi-living organism, is one of those who is less optimistic. He believes that a plan B is urgently needed. "I never thought that the Kyoto agreement would lead to any useful cut back in greenhouse gas emissions so I am neither more nor less optimistic now about prospect of curbing CO2 compared to 10 years ago. I am, however, less optimistic now about the ability of the Earth's climate system to cope with expected increases in atmospheric carbon levels compared with 10 years ago," he told The Independent. "I strongly agree that we now need a 'plan B' where a geoengineering strategy is drawn up in parallel with other measures to curb CO2 emissions."
Among those who oppose geoengineering is Professor David Archer, a geophysicist at Chicago University and expert on ocean chemistry. "Carbon dioxide released to the atmosphere will continue to affect climate for many millennia," he said. "Relying on geoengineering schemes such as sulphate aerosols would be analogous to putting the planet on life support. If future humanity failed to pay its 'climate bill' – a bill that we left them, thank you very much – they would bear the full brunt of climate change within a very short time."
Fixing the planet Could technology help save the world?
Injecting the air with particles to reflect sunlight
Volcanic eruptions release huge amounts of sulphate particles into the upper atmosphere, where they reflect sunlight. After Mount Pinatubo erupted in 1991, sulphates reflected enough sunlight to cool the Earth by 0.5C for a year or two. The Nobel Laureate Paul Crutzen suggested in 2006 that it may be possible to inject artificial sulphate particles into the upper atmosphere – the stratosphere. However, the idea does not address ocean acidification caused by rising CO2 levels. There may be side-effects such as acid rain and adverse effects on agriculture.
Creating low clouds over the oceans
Another variation on the theme of increasing the Earth's albedo, or reflectivity to sunlight, is to pump water vapour into the air to stimulate cloud formation over the sea. John Latham of the United States National Centre for Atmospheric Research in Boulder, Colorado is working with Stephen Salter of Edinburgh University and Mike Smith at Leeds to atomise seawater to produce tiny droplets to form low-level maritime clouds that cover part of the oceanic surface. The only raw material is seawater and the process can be quickly turned off. The cloud cover would only affect the oceans, but still lower global temperatures.
Fertilising the sea with iron filings
This idea arises from the fact that the limiting factor in the multiplication of phytoplankton – tiny marine plants – is the lack of iron salts in the sea. When scientists add iron to "dead" areas of the sea, the result is a phytoplankton bloom which absorbs CO2. The hope is that carbon taken up by the microscopic plants will sink to deep layers of the ocean, and be taken out of circulation. Experiments support the idea, but blooms may be eaten by animals so carbon returns to the atmosphere as CO2.
Mixing the deep water of the ocean
The Earth scientist James Lovelock, working with Chris Rapley of the Science Museum in London, devised a plan to put giant tubes into the seas to take surface water rich in dissolved CO2 to lower depths where it will not surface. The idea is to take CO2 out of the short-term carbon cycle, cutting the gas in the atmosphere. Critics say it may bring carbon locked away in the deep ocean to the surface.
Giant mirrors in space
Some scientists suggest it would be possible to deflect sunlight with a giant mirror or a fleet of small mirrors between the Earth and the Sun. The scheme would be costly and prompt debate over who controls it. Many scientists see it as contrary to the idea of working with the Earth's systems.
Interesting? Click here to explore further
No comments:
Post a Comment