We can quibble over timescales, but real climate progress is afoot

The recent commitments by the leaders of G7 nations to reduce emissions of carbon dioxide to 40-70% below current levels by 2050, and to eliminate the use of fossil fuels altogether by 2100, have raised several questions.

Are these objectives feasible? Are they consistent with national commitments? Are they sufficient to stabilise the global climate without dangerous rates of warming? And are they anything new?

The first question is the easiest. We already have the technology we need to phase out most of the significant uses of fossil fuels, without a substantial impact on living standards, or even on the rate at which living standards are improving. Coal-fired and gas-fired electricity generation can be replaced by a combination of renewables and storage technologies, with “baseload” options like nuclear and geothermal as a backup if needed.

Electric cars, and of course trains, are already available, and are well suited to the use of renewable energy sources for recharging. Some new technologies are needed in areas like new steel production and air transport, but these challenges should be solvable in the coming decades.

In broad terms, the commitments are consistent with an emissions trajectory in which greenhouse gas concentrations are stabilized at around 450 parts per million. That requires that global emissions should peak by the mid-2020s, and decline to around 50% of their current levels by 2050.

In the second half of the century, emissions need to be reduced to a level at which they are more than offset by reafforestation and other sinks – so-called “net negative” emissions.

New news?

This brings us to the final question – the issue of whether the pledges made by rich nations in the past week are new or not. The answer is that while the idea is certainly not new, what is novel is the fact that it is now receiving backing from those with real power and influence.

It’s worth remembering the reaction to Bob Brown’s suggestion, back in 2007, that Australia needed to long-term plan to phase out coal exports. Both John Howard and Kevin Rudd ridiculed the idea, arguing on the contrary that “coal is part of Australia’s long-term future”.

Even the famous Stern Review, which radically changed the terms of debate when it was released by UK climate economist Nicholas Stern in 2006, relied heavily on the existing assumption that carbon capture and storage (CCS) would allow the continued use of fossil fuels, particularly coal. By contrast, the G7 commitment doesn’t even mention CCS, although it is not explicitly ruled out either.

Of course, 2100 is further away than the phrase “long-term” might normally imply. But if fossil fuels are to be phased out, it is clear that the use of coal will end long before that of gas and oil. The export trade, supplying demand that can’t be met by domestic production in countries like China and India, will end long before that. A realistic trajectory, consistent with the G7’s commitments, implies that Australia’s exports will have to peak in the relatively near future, and then decline to zero within a few decades at the most.

Putting hard targets on the table

How does this relate to the crucial climate negotiations later this year in Paris, which will hopefully deliver an international emissions-reducion agreement covering the next 5-15 years? The G7 undoubtedly delivered a boost to the preliminary talks in Bonn, aimed at paving the way for a Paris deal.

As many observers have pointed out, the national commitments made so far add up to a lot less, in the way of emissions reductions, than the internationally agreed targets would require. However, to a large extent, this commentary misses the point.

The whole idea of globally agreed targets is to raise the bar for more specific national commitments. If the national commitments were already sufficient, there would be no need for global targets.

In this context, the recent announcements may be seen as logical implications of the previously agreed limit of 2C warming. This might seem to render them redundant. But in political and diplomatic contexts, it is one thing to announce a policy objective, and quite another to accept its logical implications.

By spelling out the fact that the target requires deep cuts in emissions by the middle of the century, and the complete phase-out of fossil fuels by the end of it, the G7 leaders have taken another, small step towards saving the planet.

John Quiggin is on the Board of the Climate Change Authority