Arithmetic of delay

So the Climate Change conference at Cancun has produced a mouse. What does that tell us about the future?

Let's start by noting our target. In 2009 a group of Nobel winners declared that, to avoid catastrophic climate change, world greenhouse gas emissions must peak by 2015. Actually, that gives a us a good chance of avoiding catastrophe - not a guarantee - which doesn't seem good enough. But let's take that for now.

Now what's the best we can realistically hope for internationally?

Principles
To achieve the Lifeboat scenario (my most optimistic scenario) we need a strong, binding, international treaty on climate change. Treaties, however, take time. The 2011 conference in Durban cannot agree a treaty - a year is too little time - but might it agree the principles of a treaty? That requires the US to agree the principle of major emissions cuts by 2050 and China to agree the principle of some restraint to its own emissions. Now these are not independent. China won't agree to anything unless the US agrees cuts and the US won't agree cuts unless China joins the process.

But the Republicans in the US Congress aren't going to agree anything and the earliest we might get a more sensible Congress is 2012 - not that that looks likely. But, just maybe, we might see a change of heart following the 2012 elections allowing agreement on principles in 2013. (Most of any agreement is negotiated in the months before the conference so 2012 is too soon.)

Treaty
So how long to get from principles to treaty?

Effective action on climate change touches every country and industry. Action needs to be decisive - which means that there will be winners and losers. Governments are not global philanthropists - they defend national interests - so they will want their people and companies to be winners not losers. Does two years sound long enough to turn principles into a treaty with teeth?

An optimist might think so. So, just maybe, we could have a successor to Kyoto by 2015.

Ratification
International treaties don't come into force until they've been ratified (ie formally approved) by a majority of the signatories. In many cases this requires approval by the national parliament and some parliaments are not controlled by their governments. (The US comes to mind again.)

It took eight years for the Kyoto Treaty to come into force due to delays by various major states. How long will ratification of the successor treaty take? This is obviously another unanswerable question but if it's eight years we may as well give up now. Can we believe in three years?

Let's make another act of optimism and say three. So the new treaty comes into force in 2018.

Implementation
Of course, we'll still only have words on paper. Now we need to consider the institutions, equipment (eg for greenhouse gas monitoring), staffing, etc. needed. But some of this could be done even before the treaty came into force if some country or group of countries was prepared to fund it. So maybe implementation need only take another year.

Reaching the peak
So, in 2019, the restraint measures in the treaty could begin to bite. Still it's likely that greenhouse gas emissions will have continued to rise since 2010 - as they did in almost every preceding year - and these things have their own momentum. Instant results are impossible even where good will exists (and it is never universal).

So maybe we could see emissions peak in 2021 and reduce, if only by 0.5%, in 2022. That's seven years later than we need to avoid the likelihood of catastrophic climate change.

What are the odds?
The 2022 date is based on five separate optimistic assumptions. Any one is conceivable but that all should prove correct is not. Therefore I conclude that greenhouse gas emissions will not peak by 2022 and may peak much later - if at all.

If saving the world climate depends on achieving peak greenhouse gas emissions by 2015 then catastrophe is already inevitable. It's past time to confront the real problems we face.