Thought du Jour

UCLA professor Jared Diamond, in his best-selling book Collapse (Allen Lane, 2005; Penguin, revised edition, 2011), popularised the thesis of British archaeologist Paul Bahn and others that the collapse of Easter Island was caused by deforestation and internal social problems, long before the arrival of Europeans. Terry Hunt and Carl Lipo argue, in The Statues That Walked (Free Press, 2011), that, despite deforestation, the islanders managed to grow sufficient food and live in relative peace until the Europeans brought germs and violence to their shore.

Paul Bahn, reviewing the book of Hunt and Lipo, concedes that the huge stone statues were moved upright for miles, without need for timber. This is an important concession, for it implies that the islanders could have been carving and moving statues up to the time of the arrival of the Europeans.  Bahn complains, however, that “coverage of work by others is incomplete”.

For example, a variety of evidence contradicts their claim of rat predation: numerous palm fruits not gnawed by rats, palm stumps burned and cut, continued germination of palms despite the rats’ presence, and the disappearance of other plant species that coexist with rats elsewhere. Hunt and Lipo’s claim that human skeletal remains show little evidence of lethal trauma is refuted by quotes from anthropologist Douglas Owsley, the author of a 1994 paper that they reference. After examining more than 600 Easter Island skeletons, Owsley stated in a 2003 BBC documentary that the extreme frequency of injuries proved that these were people at war: “They’re slugging it out, there’s no doubt about it.”

Hunt and Lipo present some of the island’s many features entertainingly, but the history of Rapa Nui is more complex than they allow.

Paul Bahn, “Anthropology: Head to head“, Nature 476 (11 August 2011), pp. 150-151.

Whether rats (who accompanied the human colonizers) or humans themselves were directly responsible for the deforestation of Easter Island is a moot point. A crucial fact – which Bahn in his review does not contest – is that the islanders were healthy, well-fed and peaceful in 1722 when the first Europeans arrived. A society that survived on an inhospitable, treeless island was devastated by previously unknown germs introduced by Europeans. A similar fate awaited numerous tribes and civilisations in the Americas following their contact with Europeans. Hunt and Lipo might overstate their case, but their thesis seems to have more merit that the ‘ecocide’ thesis popularised by Jared Diamond.

Paul Bahn is author (with John Flenley) of Easter Island, Earth Island (Thames & Hudson, 1992).

This week’s Economist has a long article on “reducing emissions from deforestation and degradation” (REDD). If REDD is to work, co-operation from forest dwellers is essential. The best and perhaps only way to obtain full co-operation is to pay them. A number of experimental projects along these lines are underway. The Economist discusses one of them, located in the south-eastern corner of the Brazilian state of Amazonas.

Novo Aripuanã is the site of a novel response to [the threat of deforestation]: the Juma Sustainable Development Reserve, an area of 600,000 hectares (1.2m acres) bordered by two highways. This is a nature reserve with an unusual twist: local people will be paid to prevent the trees from being cut down. Each family in the area has been issued with a debit card. Regular inspections will ensure that the trees are still standing: as long as they are, families will have 50 reais ($28) a month credited to their accounts.

These funds come from the rich world, where governments and companies that cannot reduce their own emissions cheaply are prepared to pay others to reduce emissions on their behalf (as “carbon offsets”). Not cutting down trees in endangered areas prevents emissions that would otherwise have occurred, which gives untouched forest huge financial value—and provides people who live in the forest with an incentive to preserve it.

This idea is known as “avoided deforestation” or “reducing emissions from deforestation and degradation” (REDD). At the moment REDD is not so much a plan as a collection of proposals and some working schemes, like Juma. The fate of the forests in Brazil, Indonesia, the Philippines and elsewhere around the world could hang on the success of this approach. But there will need to be substantial international commitments to reduce global emissions to create demand for the carbon offsets that REDD schemes can provide. This means a lot hangs on a deal being struck in December in Copenhagen, where countries will meet to negotiate a new climate treaty.

“Paying to save trees: Last gasp for the forest”, The Economist, 26 September 2009.

Preventing deforestation is important for the climate agenda because “carbon emissions from deforestation account for some 18% of global greenhouse-gas emissions, more than all the world’s trains, cars, lorries, aeroplanes and ships combined”. This informative essay is – for The Economist – exceptionally long, and worth reading in its entirety.