James Lovelock: Schemes to 'Reverse' Global Warming Could Lead to Disaster

By James Lovelock, The Guardian. Posted September 21, 2009.

The idea of serious scientists and engineers gathering to discuss schemes for controlling the world's climate would a mere 10 years ago have seemed bizarre, or something from science fiction. But now, well into the 21st century, we are slowly and reluctantly starting to realise that global heating is real. We may have cool, wet summers in the UK, but we are fortunate compared with the Inuit, who see their habitat melting, and Australians and Africans who suffer intensifying heat and drought. We should not be surprised that public policy is edging ever nearer to geoengineering, the therapy our scientists are considering for a fevered planet.

Our senior scientific society, the Royal Society, met at the start of the month to launch the report "Geoengineering the Climate" and to hear from its representative scientists. The meeting was hosted by the president, Lord Rees, and the chairman was Professor John Shepherd, who chaired the study group. The goal, as Prof Shepherd explained in the Guardian in April, was to investigate theories of "intervening directly to engineer the climate system, so as to moderate the rise of temperature" and to "separate the real science from the science fiction".

Geoengineering is about deliberately changing the air, oceans or land surface of the world to offset global heating with the hope of restoring the cooler world we enjoyed in the last century. We are now fairly sure that the Earth has grown hotter by about one degree Celsius as a consequence of our own action in taking away as farmland the forests and other ecosystems that previously acted to keep the Earth cool. We also have increased by 6% the flow of CO₂ into the air by burning coal, oil and natural gas. If we started global heating, can we reverse it by engineering?

The first scientist to consider geoengineering seriously was the Russian geophysicist Mikhail Budyko. In the 1970s he proposed that we could offset global heating by spreading in the stratosphere a fine dispersion of particles that reflected sunlight back to space; he based the idea on the observation that volcanic eruptions that did this were followed by global-scale cooling. He suggested that we could mimic the effects of a volcanic eruption by putting an aerosol into the stratosphere. His idea was confirmed by the detailed observations and analysis of the effect of Mount Pinatubo's eruption in 1991. It injected 20m tonnes of sulphur dioxide into the stratosphere and this soon oxidised to form the white reflecting particles that offset global heating for three years. It is within our capacity to put this much sulphur dioxide into the stratosphere.

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James Lovelock is an independent scientist, author, researcher, environmentalist and futurist. He proposed the Gaia hypothesis, in which the Earth functions as a superorganism. His most recent book is The Vanishing Face of Gaia: A Final Warning.

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