Two Degrees of Separation from Reality

cartoons by joshThe UN is calling on national leaders to back a global agreement on reducing human-produced CO2 emissions with the stated intention of limiting “global warming to 2C degrees above the pre-industrial level”. This pact is to be signed in Paris in December and Australia has agreed to participate. Thrashed out at the 2014 Lima conference, the process called upon individual nations ‘ready to do so’ to submit national pledges by the first quarter of 2015, with Australia saying it would take the pledge sometime around now.

Yet it remains unclear if the Australian government subscribes to the 2C target.The recently released issues paper, ‘Setting Australia’s post-2020 target for greenhouse gas emissions‘, does not refer to this aim. I have sought clarification, unsuccessfully, from Environment Minister Greg Hunt and my local member, Dr Peter Hendy, a Liberal. The 2C limit is a very specific target, one that doesn’t leave a lot of wiggle room.This is as it should be if one accepts the prognostications of catastrophe upon which the alleged need for this agreement is based.(Which, for the record, I don’t. But let us play the game anyway.)

The obvious question: Exactly how much atmospheric CO2 will produce such a warming? The IPCC tells us the warming effect of doubling the atmospheric CO2 concentration is anywhere between 1.5C degrees and 4.5C degrees (So much for ‘settled science’!) How are individual governments to know what emission cuts would be necessary and sufficient to meet the aim? Further, what official guidance has been issued to countries? If such guidance exists it is not widely published, as is the sound-byte quotable 2C degree limit.

In the case of Australia, one would think such guidance would be issued by the Department of the Environment. but I could find no reference to any advice on its website. So I checked the Climate Change Authority (CCA), which has issued some guidance, based on a paper by Meinshausen et al (2009) which assigns various probabilities of limiting warming to 2C against various emission scenarios. The report can be read in full here.

These scenarios are based on total cumulative global CO2 emissions (called global budgets) from 2000 to 2050. There are four of them, each equating to various probabilities of limiting warming to 2C.

Probability of remaining within 2C 80% 75% 67% 50%
GT CO2 900 1010 1170 1450
GT CO2e 1370 1520 1700 2020

The “budget” upon which the CCA has chosen to base its’ recommendations is 1700 GT (gigatonnes) of CO2 equivalent between 2000 and 2050. As a point of reference, the global CO2 equivalent emission for 2014 is roughly 50GT. And it is worth noting that the Authority recognises roughly 40% of this 1700GT budget has already been used between 2000 and 2014. Thus we have a residual global budget of only 1020GT of CO2e to 2050.

According to Meinshausen, limiting emissions to this budget would deliver a probability of 67% of not exceeding 2C degrees. The CCA report recommends that Australia’s ‘fair share’ of this residual budget (2013 to 2050) is 10.1GT. This works out at 0.27GT per annum. Australia currently emits approx. 0.6GT CO2 per annum. The CCA report says that the pathway to achieving the desired cuts is flexible, but the principle is that the overall budget should not be breached.

While the CCA has issued some interim targets, for simplicity’s sake let us just look at the overall picture: Under business-as-usual we would emit 22GT by 2050, so we are looking at an overall cut of greater than 50%. What is the likelihood that the Australian government will sign up to something like this in December?

It’s even more problematical when one looks at the global picture. Let’s assume the rest of the world adopted the same target (1020GT CO2 from 2015 to 2050). Currently, China emits roughly 15GT CO2 per annum and its emissions are forecast to grow until 2030, when, supposedly, they will peak.

The developed world currently emits 24GT CO2 pa. The developing world (not including China) emits roughly 15GT CO2 pa and its emissions are also forecast to grow. (Source: )

In 2014 China’s emissions grew at 3%. If that growth were to continue until 2030 — and why shouldn’t it, China having been given carte blanche by President Obama to do just that? — and then peak, China will have emitted a total of approximately 760GT CO2 by 2050. If the developing world also grew at 3% until 2030 it would have emitted the same, 760GT. So, globally, we will have consumed 1520GT and blown our global budget of only 1020GT CO2.

Even if the developed world achieved a 50% cut in emissions, it would still emit roughly 430GT by 2050. Against a budget of 1020GT, actual emissions would total 1950GT. I think my assumptions are conservative as to the growth in emissions from China and the developing world and ambitious as to the cuts in emissions achievable by the developed world.

So even if Australia achieved its 10GT budget, in the best case, the world will still overshoot the mark by 90%, equating to a probability (according to Meinshausen) of limiting warming to 2C of only 50%. The government’s position is that it will base its cuts on what the rest of the world does while also insisting it respects the science of climate change. There’s not a lot of science in this process.

Already, it seems, some of the lead UN figures in the process are hedging their bets and suggesting that the 2C target is not the be-all and end-all. As it is, the process instigated at Lima resembles nothing so much as an office farewell party, as in “We’re passing the hat around for Charlie, who is he’s leaving the company after 30 years’ service. We’d like to get him a gold Rolex but chip in whatever you can and we’ll get what we can afford.”

While it’s highly probable that the Paris outcome will be the equivalent of a Hong Kong knock-off, two things are very certain indeed: The warmist’s two-bob watch will cost a whole lot more than it’s worth and, unlike our fictional Charlie, the UN’s leeches will be clamouring for even more next year.

(editor’s note: all CO2 numbers cited above are actually CO2 equivalents, meaning they include other greenhouse gases, such as methane etc)