Dr Pep Canadell, CSIRO and Executive Director of the Global Carbon Project

Dr Pep Canadell, CSIRO and Executive Director of the Global Carbon Project (Photo: Charles Tambiah)

2°C climate target a hot topic

Carbon dioxide emission reductions required to limit global warming to 2°C are becoming a receding goal based on new figures reported in the latest Global Carbon Project (GCP) calculations published in Nature Climate Change.

  • 3 December 2012

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Glen Paul: G’day, and welcome to CSIROpod, I’m Glen Paul.  A new set of figures released by the Global Carbon Project is showing a disturbing trend in relation to the carbon dioxide emission reductions required to limit global warming to 2° Celsius above pre-industrial levels.  The calculations, published in Nature Climate Change, reveal the need for a sustained global CO2 mitigation rate of at least 3% if global emissions are to peak before 2020, and follow an emission pathway that can keep the temperature increase below 2° Celsius.

Executive Director of the Global Carbon Project and co-author of the Paper, CSIRO’s Doctor Pep Canadell, joins me on the phone.  Pep, just how concerned should we be about these figures?

Dr Canadell: Well, I think that we have to be concerned, very concerned, because this one, like all the other ones over the last ten years, it has been yet another year of very strong growth in emissions globally.  Let me just give you a couple of numbers.  In 2012 we are basically to set to reach by the end the unprecedented amount of 36 billion tonnes of carbon dioxide going into the atmosphere at annual growth rates around 3%.  And to put this in perspective, I mean this is more than 50% more emissions when we first started talking about climate change mitigation in the early ’90s, and it is three times a faster growing rate than we had also then.  So it is very concerning in terms of the fact that we continue this high level of emission growth rates.

Glen Paul: And what’s holding us back from achieving the CO2 mitigation rate that would be required to keep the temperature down?

Dr Canadell: So they’re really complex issues, in the sense that we see for instance in 2011 80% of the growth in emissions we observed are coming from China alone.  Now China is in the path of development, a path of urbanisation which will not stabilise until 2030, but of course China is not alone.  There’s a lot of emerging economies, there are a lot of economies which come from per capita emissions extremely low, like India, yet with more than a billion people you expect that energy consumption will be growing, not over the next ten years, but over the next many decades.  And if a rapid transformation of the energy system is not occurring, those energy systems will be releasing, you know, growing amount of carbon dioxide.

Glen Paul: And if that then does lead to a temperature increase beyond 2° Celsius, how is that going to impact the planet?

Dr Canadell: Let me just first say that at this point with the growth rates we’ve seen over the last ten years, we’re following the path that the UN Framework Convention on Climate Change is using to indicate emissions growth to lead us to about four to 6° global warming by 2100, so if we do nothing but continue at the same rates we’ll be fundamentally in a planet that will be cooking by the end of this Century.

Now what needs to be done to change this dramatic pathway to a place where simply we don’t want to go, and I think that countries have shown in the past that it is possible, rapid technological energy transformations.  We actually in part of the Paper, we have studied what happened for instance to France early in the ’80s when they moved from energies to a transition to nuclear energy, what happened to the U.K. when they moved from coal to a natural gas, and what happened is plenty of other examples, Sweden also, and some of these countries were able to for a decade almost bring their carbon emissions for non-climate reasons, for energy reasons, down to a growth mitigation rate of three and four, which is exactly what we need.

Now the big question is can we extrapolate those examples of regions and for just a decade to the globe for, you know, multiple decades?  You know, we don’t know, but we do have examples of very rapid energy transformation.

Glen Paul: OK, well that’s something.  What about melting permafrost if things don’t go to plan and temperatures do increase?  I’ve heard this discussed a little of late, and obviously there’ll be a release of greenhouse gases such as methane on the back of that, which will have a snowball effect.  What happens if this monster from the deep, as I’ve heard methane being described, is allowed to escape?  Is there any going back at that point?

Dr Canadell: Basically the 2° level that Copenhagen accord agreed in 2009 was what we call a social construct.  We don’t have a magic bullet to say that after 2° all these earth system triggers will start and we’ll get in big trouble.  This really pulling together all the science that we know on impacts, even pulling together what we think that we could potentially achieve, you know very aggressively, but could be still on our hand.  And so it was settled on 2°.

Some of these triggers, like the permafrost melting, are believed that may have already started.  Now we don’t expect massive amounts of methane to come up from the permafrost regions of the Northern latitudes but we could expect new chronicle sources of carbon dioxide and methane that would just make our mitigation efforts even harder, you know, to achieve.

We don’t know exactly when these things are going to happen, but we do know that it is more probable, you know, to happen, to be triggered at higher temperatures than at lower temperatures.

Glen Paul: So how did the Global Carbon Project come up with these latest figures?

Dr Canadell: So we look at very carefully all the emission scenarios, that’s the scenarios that look at plausible futures of emissions to the next hundred years that have been associated with the UN Framework Convention on Climate Change, and particularly with IPCC, the Intergovernmental Panel Change.  So there’s more than 50 of such scenarios, so we went over the last 20 years, you know just put it all together, and it was a shocking realisation to see that out of those 50 scenarios that have been developed over the last 20 years by the UN, almost consistently on all of them we’re tracking now with the real emissions we’re seeing is the highest most carbon intense pathways, which as I mentioned before will take us to anywhere, if we don’t do anything, to four to 6° temperature at the end of this year.

The other thing that we do rely is these large datasets and modelling output that come from more than 15 institutions around the world, so the Global Carbon Project working with all these institutions, we come together to bring and provide this data consistently, and the model output consistent, so that we can actually cost what we call a full global carbon budget, to understand where and how much the emissions that we put from human activities, but also where all these emissions have gone – accumulate in the atmosphere, which of course is our concern, but also how much has gone into the oceans and into the land.

Glen Paul: So taking all that into consideration, how confident are you that we’ll be able to keep the temperature increase below 2° Celsius by 2020?

Dr Canadell: We’re exceptionally concerned.  In fact we think that we probably, we’re just about to miss it, if we have not yet missed it.  The reality is that with the growth rates we’re seeing it is difficult to envision that by 2020, as it is required by some of the models, we can actually start turning the wave around, so by around 2020 emissions should in absolute terms to start declining, and it is difficult to see when you have some of the forces behind the growth that we see, like China, of India, growing annually their emissions of about eight to 10%, so I think that it will take more than a decade to reach that, and that will put us really at the fringe as to whether we can really make it to 2°, or we really need to move into a higher, warmer world, and certainly with policies and strategies for adaptation, which will be become, no doubt about it, very important in the near future.

Glen Paul: And just how much influence then is the Global Carbon Project having on Governments in getting them to want to play ball on the mitigation challenge?

Dr Canadell: Well the role of the GCP is always the one of providing the most revised data, and the most up to date data possible, that the community working in the topics, the larger global carbon cycle community around the world, is able to put together, and to do it in a timely manner so that, as we do every year, release the new numbers, the new datasets, and the new publications with analysis, by the time that the conference of the party meets.

So our release of course, you know, it’s in the middle of the conference, and that’s one way we learned, you know, to be highly influential by just showing the latest numbers.  We’re also running a side event in Doha where also the latest numbers will be shown.

Glen Paul: Right.  And the Paper is appropriately called The Mitigation Challenge To Stay Below 2°, and can be found online in Nature Climate Change, which I’m sure a Google search will quickly reveal.  So there are some positives, it’s not all doom and gloom, and I thank you very much for explaining it to us today, Pep.

Dr Canadell: Thank you very much.

Glen Paul: Doctor Pep Canadell.  And to find out more about the research, or to follow us on other social media, just visit www.csiro.au.