It's time to 'Do the math' again

By David Spratt

Have we gone mad? A new report released today explains why contemporary climate change policy-making should be characterised as increasingly delusional.

As the deadline approaches for submissions to the Australian government's climate targets process, there is a flurry of submissions and reports from advocacy groups and the Climate Change Authority.

Most of these reports are based on the twin propositions that two degrees Celsius (2°C) of global warming is an appropriate policy target, and that there is a significant carbon budget and an amount of "burnable carbon" for this target, and hence a scientifically-based escalating ladder of emission-reduction targets stretching to mid-century and beyond.

A survey of the relevant scientific literature by David Spratt, "Recount: It's time to 'Do the math' again", published today by Breakthrough concludes that the evidence does not support either of these propositions.

The catastrophic and irreversible consequences of 2°C of warming demand a strong risk-management approach, with a low rate of failure. We should not take risks with the climate that we would not take with civil infrastructure.

There is no carbon budget available if 2°C is considered a cap or upper boundary as per the Copenhagen Accord, rather than a hit-or-miss target which can be significantly exceeded; or if a low risk of exceeding 2°C is required; or if positive feedbacks such as permafrost and other carbon store losses are taken into account.

Effective policy making can only be based on recognising that climate change is already dangerous, and we have no carbon budget left to divide up. Big tipping-point events irreversible on human time scales such as in West Antarctica and large-scale positive feedbacks are already occurring at less than 1°C of warming. It is clear that 2°C of climate warming is not a safe cap.

In reality, 2°C is the boundary between dangerous and very dangerous climate change and 1°C warmer than human civilisation has ever experienced.

In the lead up to the forthcoming Paris talks, policy makers through their willful neglect of the evidence are in effect normalising a 2.5–3°C global warming target.

This evidence in "Recount: It's time to 'Do the math' again" demonstrates that action is necessary at a faster pace than most policy makers conceive is possible.

Related

- It's time to 'Do the math' again
http://www.climatecodered.org/2015/04/its-time-to-do-math-again.html

- RECOUNT - It's time to 'Do the math' again
http://media.wix.com/ugd/148cb0_938b5512abfa4d4e965ec8cc292893f7.pdf

- Two degrees of warming closer than you may think
http://arctic-news.blogspot.com/2015/02/two-degrees-of-warming-closer-than-you-may-think.html

- The real budgetary emergency and the myth of "burnable carbon"
http://arctic-news.blogspot.com/2014/05/the-real-budgetary-emergency-and-the-myth-of-burnable-carbon.html

It's time to 'Do the math' again | by David Spratt http://arctic-news.blogspot.com/2015/04/its-time-to-do-math-again.html

Posted by Sam Carana on Thursday, April 23, 2015