How did it all start?
Corinne Le Quéré - It started in 2004 at the annual meeting of the Global Carbon Project Scientific Committee in Goa, India. We were discussing how to increase the relevance of the carbon research community in support of the climate policy process. We felt there was a lot we could do but we lacked a focus.
The initial rational for the annual updates of the global carbon budget was thus primarily to assist the climate policy process, but we also though it would help bring the carbon research community to work more closely together.
The global carbon budget was updated by the IPCC every 6-7 years. We felt it would be useful to have more regular updates, and we had all the information we needed for that.
What have been the most significant findings so far?
Corinne Le Quéré - The incredible evolution in global fossil fuel emissions has really been the most obvious and critical finding. As soon as we started the updates in 2005 it was evident that the emissions were rising much more rapidly than they had done in the 1990s, by 2-3 percent each year. We were able to identify the regional and global socioeconomic drivers, thanks to Mike Raupach’s leadership on this. This year, we can see a break in this rapid growth trend, which will be fascinating to follow.
We also found out a lot about the carbon sinks and how they respond to climate change. The annual update of the global carbon budget has triggered new analysis of decadal trends in the sinks, their causes and distribution. I think that has been very productive.
Finally we’re realising that our capacity to quantify emissions from land-use change is limited at the moment. We’re working on it and I think we could make good progress in the coming years.
How have the interactions between researchers and policymakers developed?
Corinne Le Quéré - This effort has opened up dialogues between researchers and policymakers in several countries, and that’s one of its biggest legacies. We have worked with policy advisers worldwide, particularly in the UK, Norway, Germany and several European countries, the US, Australia and China. We’ve provided early and specific data. I think the interactions improved understanding and have been very fruitful on both sides.
The global carbon budget is ten editions old, how do you feel about it?
Corinne Le Quéré - I feel we have accomplished something. The updates are tangible, they are used by researchers, policymakers, teachers, bloggers and the media. Our PowerPoint slides and Atlas show up in a range of presentations and forum. And yet we’ve also produced high-quality research published in peer-reviewed journals, which benefit the research community in their own sake. I find the effort rewarding.
When the budget was first published what was the reaction?
Corinne Le Quéré - There was an immediate interest from the media and policymakers which has grown through time.
There were lots and lots of suggestions from scientists which have been really helpful. Through the ten iterations we have brought more people on-board, to improve the data and methods, and to provide the highest transparency, traceability, and timeliness of our reporting.
What do you think the main effect of the budget has been?
Corinne Le Quéré - I like to think that carbon cycle science is more visible because of the annual updates, and that policy discussions are better informed.
One effect we had not really anticipated is that within the carbon community we now keep better track of how carbon cycle research evolves. This is particularly valuable.
What have been the biggest challenges over the last ten editions?
Corinne Le Quéré - Delivering on time has been the biggest challenge. We have a timeline that is extremely tight for such a complex exercise. Aligning the access to preliminary data, the data and model assessments, and the synthesis of results is already difficult enough. In addition, we have set ourselves the challenge to try and publish at least one paper in a high-impact journal every year, and to publish the detailed methodology and full data. Not all of our papers have been accepted and we've had some difficult years. But overall trying to combine timeliness and quality is the biggest challenge, and that is also what makes this effort unique.
I had not anticipated that so many people would be willing to take the challenge of delivering quickly and at high quality standards. Several groups around the world have taken ownership of their annual contributions, for a fantastic teamwork. We’ve managed to pull these updates together for 10 years also because of outstanding support from journal Editors and staff that go out of their way to ensure timeliness in the delivery, and thanks to funding from a range of public and private funders.
Corinne Le Quéré - In my view, we have built something precious, that I would like to nurture and continue to develop. But I the same time, I realise what a toll this takes on the research community. After COP21 in Paris settles, it will be a good time to consult the research community and the users and decide under what form the updates of the global carbon budget should evolve in the future.