A changing climate of opinion? The Economist reports on geoscale engineering to avert dangerous climate change

The Economist, September 4th 2008

Some scientists think climate change needs a more radical approach. As well as trying to curb greenhouse-gas emissions, they have plans to re-engineer the Earth. There is a branch of science fiction that looks at the Earth’s neighbours, Mars and Venus, and asks how they might be made habitable. The answer is planetary engineering. The Venusian atmosphere is too thick. It creates a large greenhouse effect and cooks a planet that is, in any case, closer to the sun than the Earth is to even higher temperatures than it would otherwise experience. Mars suffers from the opposite fault. A planet more distant from the sun than Earth is also has an atmosphere too thin to trap what little of the sun’s heat is available. So, fiddle with the atmospheres of these neighbours and you open new frontiers for human settlement and far-fetched story lines.

It is an intriguing idea. It may even come to pass, though probably not in the lifetime of anyone now reading such stories. But what is more worrying—and more real—is the idea that such planetary engineering may be needed to make the Earth itself habitable by humanity, and that it may be needed in the near future. Reality has a way of trumping art, and human-induced climate change is very real indeed. So real that some people are asking whether science fiction should now be converted into science fact.

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Melting Artic ice acts as a CO2 sink, whilst Antarctic wintertime ice is on the increase

"Antarctic sea ice increases despite warming" (New Scientist, 12 September 2008)

The amount of sea ice around Antarctica has grown in recent Septembers in what could be an unusual side-effect of global warming, experts say.

In the southern hemisphere winter, when emperor penguins huddle together against the biting cold, ice on the sea around Antarctica has been increasing since the late 1970s, perhaps because climate change means shifts in winds, sea currents or snowfall.

At the other end of the planet, Arctic sea ice is now close to matching a September 2007 record low at the tail end of the northern summer, in a threat to the hunting lifestyles of indigenous peoples and creatures such as polar bears.

"The Antarctic wintertime ice extent increased…at a rate of 0.6% per decade" from 1979 to 2006, says Donald Cavalieri, a senior research scientist at the NASA Goddard Space Flight Center in Maryland.

At 19 million square kilometres, it is still slightly below records from the early 1970s of 20 million, he says. Since 1979 however, the average year-round ice extent has risen too.

(link to full article)


"Melting ice caps could suck carbon from atmosphere" (New Scientist, 10 September 2008)

It’s not often that disappearing Arctic ice is presented as good news for the planet. Yet new research suggests that as the northern polar cap melts, it could lift the lid off a new carbon sink capable of soaking up carbon dioxide.

The findings, from two separate research groups, raise the possibility – albeit a remote one – of weakening the greenhouse effect. The researchers say the process of carbon sequestration is already underway. Even so, the new carbon sink is unlikely to make a significant dent in the huge amounts of CO2 pumped into the atmosphere by industrial activities.

Kevin Arrigo and colleagues at Stanford University studied satellite data collected between 1998 and 2007 to see how sea surface temperatures and the quantities of sea ice and phytoplankton had changed during that time.

Phytoplankton produce chlorophyll to obtain energy from the sun and assimilate CO2, and so increased phytoplankton productivity would remove more carbon from the atmosphere.

"We found that as sea ice diminishes, annual productivity goes up," says Arrigo. Satellite remote sensing measures the amount of chlorophyll in surface waters, and so provides an estimate of ocean productivity.

(Link to full article)

” Climate change isn’t something to be believed or disbelieved”

The Guardian, September 4th 2008 (by Martin Parry, lead author of the 2007 assessment of impacts and adaptation by the IPCC)

"The media love a good argument, and what better than to pitch polemicists against each other from opposite ends of the spectrum? Thus we are given Björn Lomborg v Oliver Tickell in a so-called "climate debate" (Tickell’s apocalyptic view obscures the solutions; Lomborg’s stats won’t mean much underwater, August 21). Regrettably, we learned from this only that sensible solutions are unlikely to flow from entrenched and extreme positions. Most scientists are amazed and alarmed that the issue of climate change should be treated as an article of faith – something either to be believed or disbelieved – rather than a problem surrounded by a lot of uncertainty. What we got from these two was very misleading.

Lomborg claimed: "A lead economist of the IPCC [Intergovernmental Panel on Climate Change] did a survey of all the problems and all the benefits accruing from a temperature rise over this century of about approximately 4C. The bottom line is that benefits right now outweigh the costs." There have been a few studies of the current effects of climate change (for example, on ice shelf and glacier retreat, and on plants and animals) and the IPCC has concluded these are happening faster than had been expected. But despite what Lomborg says there has been no useful assessment of whether these are beneficial or not, because aggregation of effects involves meaningless trade-offs such as comparing the destruction of Inuit communities with the benefits of ice-freed shipping lanes.

Lomborg believes that 4C of global warming "will not be a challenge to our civilisation" and derides Tickell, whom he quotes as stating that warming of this amount would bring "the beginning of the extinction of the human race". Both of these are heroic conclusions, since there has been no study of the limits to our adaptive capacity. The climate change issue has never been about whether we can survive or not, but keeping damages and costs to a tolerable level. The IPCC concluded in 2007 that we risk billions more people being short of water due to climate change, and hundreds of millions at risk of flooding and hunger. That is a lot of suffering, but not the end of civilisation.

There is a strong emerging view, proposed by the IPCC in its latest assessment in 2007, that a careful mixture of mitigation (reducing emissions) and adaptation will be necessary to meet the challenge of climate change. And this is broadly accepted by governments now striving for agreement by the end of next year. The polarised views of both Tickell and Lomborg miss this completely. We know we cannot avoid some serious climate change (our vacillation over the past 10 years has put paid to that), but we can avoid the worst of it. At a minimum we will have to adapt to about 2C of warming. The choice still available to us is whether we should try to avoid more than this amount of warming. Common sense suggests we should, since we do not really know what impacts the future holds, and we risk repeating the mistake of the movie producer Lew Grade who, looking back on the mounting losses of his film Raise the Titanic, concluded: "It would have been cheaper to lower the Atlantic."