The Rudd Government’s Climate White Paper has been roundly criticised by conservationists on the grounds the abatement targets are too weak and the industry compensation too high. CPRS apparently now stands for Carbon Polluters Rorts Scheme rather than the Carbon Pollution Reduction Scheme.

According to those with a conservation bent, the main flaw in the policy is that the abatement target range for Australia (5-15% by 2020 and 60% by 2050 on 2000 levels) is consistent with an atmospheric greenhouse gas stabilisation target of 550 parts per million (ppm) of carbon dioxide equivalents (CO2-e). Most conservationists advocate a stabilisation objective below 450 ppm CO2-e on the grounds it would give the globe a good chance of avoiding warming of greater than 2 degrees C above pre-industrial levels. The science suggests a 550 ppm outcome is likely to lead to an increase in the global average surface temperature of around 2 to 4.5C, with a best guess of 3C. Hence, the Government’s policy is consistent with an atmospheric concentration outcome that locks in a substantial risk of major climate-related disturbances, or so the argument goes.

What has been overlooked in this analysis is that the proposed abatement targets for Australia are more consistent with a 650 ppm outcome than a 550 ppm one. This discrepancy can be traced to two main factors. Firstly, the Government’s proposal involves what many would regard as an inequitable division of global emissions entitlements between developed and developing countries. Under the Government’s scheme, developed countries would receive approximately 32 per cent of cumulative emissions entitlements over the period 2011 to 2050 (this is the period that counts). However, on average, they would have a mere 15 per cent of the global population over this period. Apparently, people in the developed world deserve a double helping of the property rights stemming from the absorptive capacity of the Earth’s climate system.

An argument can be made that developed countries need some time to transition their economies. However, this type of split is beyond what most would regard as equitable. From a more practical perspective, it is beyond what developing countries are likely to accept.

The second flaw in the Government’s abatement target proposal is that it is based on optimistic assumptions about the functioning of carbon sinks in a warmer world. The science suggests that as average temperatures increase, the absorptive capacity of the Earth’s carbon sinks are likely to decline, resulting in a greater proportion of each unit of emissions remaining in the atmosphere. If this risk is not taken into account, the atmospheric concentration of greenhouse gases could be higher than expected, along with the associated warming.

The modelling underpinning the Government’s abatement targets takes an optimistic approach to this risk. The Government’s model provides cumulative global emissions over the 21st century for a 550 ppm outcome of around 850 gigatonnes of carbon (GtC). Modelling undertaken by the Met Office in the United Kingdom suggests this number could be around 650 GtC due to the weakening of terrestrial and ocean sinks. The larger global emissions “budget” adopted by the Government ensures the associated abatement targets are much softer than they arguably should be.

When these two issues are combined, the White Paper starts to look like a 650 ppm plan, possibly higher. For the Government’s plan to lead to a 550 ppm outcome, developing countries would have to catch a good dose of the Christmas spirit next year in Copenhagen, carbon sinks would have to be unresponsive to climate change (something the current science suggests is unlikely) and/or new technologies would have to emerge that draw carbon from the atmosphere. These are all possibilities, but I wouldn’t want to put money on any of them, let alone the welfare of the planet.