ONE TOWN SQUARE: at the intersection of peak oil, climate change, and land use

Mark Lynas, author of Six Degrees: Our Future on a Hotter Planet, has an article at the Guardian telling how a group of climate, economics, and policy-making specialists came up with three alternative visions of the future. they then asked experts at the Met Office Hadley Centre to run them through its climate models to give each a projected temperature rise. He reports that the results were both surprising and profoundly disturbing.

The most pessimistic scenario was “agree and ignore” - a world where governments meet to make commitments on climate change, but then backtrack or fail to comply with them. This scenario seems most likely. For example, a study by a panel of leading British experts concludes Britain will find it ‘impossible’ to meet its targets. Oregon’s targets are not ambitious enough and the mechanisms for achieving them don’t exist. This scenario projects emissions on an upward trend until 2045.

A more optimistic scenario, called “Kyoto plus,” represents the best outcome that can plausibly result from the current process. Governments make a strong agreement in Copenhagen in 2009, binding industrialized countries into a new round of Kyoto-style targets, with developing countries joining successively as they achieve “first world” status. Ominously, this scenario still sees emissions rising until 2030.

The third scenario - called “step change” - envisaged massive climate disasters around the world in 2010 and 2011 causing a sudden increase in the sense of urgency surrounding global warming. Energized, world leaders ditch the Kyoto approach, instead focusing on the companies that produce fossil fuels in the first place. The UN sets a global “upstream” production cap and auctions tradable permits to carbon producers. A strong carbon cap means that global emissions peak as early as 2017.

“Agree and ignore” sees temperatures rise by 4.85C by 2100 (with a 90% probability); for “Kyoto plus,” it’s 3.31C; and “step change” 2.89C.

This is what Lynas finds distressing: no politically plausible scenario we could envisage will now keep the world below the danger threshold of two degrees, the “official target” requiring that atmospheric CO2 levels rise no higher than 450 ppm. This means that all scenarios see the total disappearance of Arctic sea ice; spreading deserts and water stress in the sub-tropics; extreme weather and floods; and melting glaciers in the Andes and Himalayas.

Remaining on a Kyoto-type track almost surely means triggering the collapse of the West Antarctic ice sheet and crossing thresholds that involve massive methane release from melting Siberian permafrost. Business as usual means that up to 80% of all species on earth could be driven to extinction by the magnitude and rapidity of warming. Much of the planet’s surface would be uninhabitable to humans. Billions, not millions, of people would be “displaced” [now there's a sanitized euphemism].

What Lynas doesn’t mention is that the 2.89C increase resulting from the “step change” scenario carries a high risk of the same consequences. Avoiding catastrophic climate change will require that we get atmospheric CO2 on a path back down to 350 ppm.

Economist Ross Garnau, the architect of Australia’s response to climate change, warns humanity will probably lose the fight against climate change.

“The issues are too complex, the vested interests surrounding it too numerous and intense, the relevant timeframes too long. Climate change policy remains a diabolical problem.”

He holds out a slight hope - if we can summon the courage and will to act quickly.

“There is a chance - just a chance - that Australia and the world will manage to develop a position that strikes a good balance between the costs of dangerous climate change and the costs of mitigation.

“The consequences of the choice are large enough for it to be worth a large effort to take that chance, in the short period that remains before our options diminish fatefully.”