"We?re Not Seeing any Discernable Effects of the Kyoto Protocol on Global Emissions"
In a recent Earth science conference in Beijing, Michael Raupach, a carbon-cycle scientist as well as a participant in the Global Carbon Project, presented some unsettling findings about current global carbon emissions. He answered Scitizen's questions.
Can you briefly introduce the Global Carbon Project?
The Global Carbon Project is a part of a group called the Earth Systems Science Partnership (ESSP) which consists of four international research programs who have come together to do research on major interactive questions dealing with the Earth’s system. Those 4 programs are the International Geosphere-Biosphere Programme (IGBP), the World Climate Research Programme (WCRP), the International Human Dimensions of Global Change Programme (IHDP), and Diversitas, the biodiversity program. Those four have each been going on for a period between 10 and 30 years, depending on the program, to look at Earth system questions in their own field. They realized about 7 years ago that there are a lot of questions that are interactive which span these fields, so they came together and formed a partnership called the ESSP. That partnership started several projects that cut across all of these fields; one of those projects is the Global Carbon Project—that’s the one we’re talking about now.
The way that it works is to bring together scientists dealing with the natural dimensions of the carbon cycle (the biophysical flows of carbon between atmosphere, land, and ocean), and also scientists dealing with the human dimensions of the carbon cycle. Humans are major drivers of the carbon cycle through changes in land use, and particularly through emissions—which is what we’ll be talking about in a moment—and the efforts of human societies to control the carbon cycle by cutting back human impact on the carbon cycle are also now an important part of the whole system. The Global Carbon Project attempts to put together both the natural-science and the human-science perspectives on the carbon cycle, with the philosophy that humans are just as much actors, participants, in the carbon cycle as natural phenomena have been for millions or billions of years. In the recent past, humans have started to rival the natural phenomena in their influence on the carbon cycle.
What is the current state of global carbon emissions on the whole?
The state of current carbon emissions is that they are rising very rapidly. If we look at the balance of CO2 in the atmosphere, there are two major inputs of CO2 and two major exports that remove CO2 from the atmosphere. The first major input is fossil-fuel emissions, which at the moment accounts for 7.9 billion tons of carbon as CO2 entering the atmosphere every year. The second input is from land-use change, mainly from the clearing of forests, now occurring predominantly in the Tropics. This input is currently about 1.5 billion tons of carbon every year. On the output side, the two big fluxes are an uptake of CO2 from the atmosphere to the oceans and an uptake of CO2 from the atmosphere to land surfaces. These two fluxes, between them, absorb about 55% of all human emissions, that is, the sum of fossil fuel burning and land-use change. The remaining 45% of human CO2 emissions accumulate in the atmosphere. This part is what is causing atmospheric CO2 to go up by about 2 parts per million (ppm) every year at the moment. We’re at 380 ppm this year; next year we’ll be at about 382 ppm, and so on. The rate of increase of emissions, which was the subject of the paper we gave a couple of weeks ago to the ESSP Conference in Beijing, has gone from 1% per year during the 1990s to about 2.5% per year on average through the period 2000 to the present. Emissions are therefore accelerating, going up, more quickly each year.
Are there differences in levels in different regions of the world? Where does China stand on emissions levels?
There are differences between the rates of increase in different parts of the world. The largest rates of increase occur in developing countries and China is prominent among those countries, of course. Who you say is the biggest contributor depends very much on your time scale of interest: for example, if you look at rate of increase of emissions, then China has the greatest rate of increase. If you look at the current emission flux, which is the total emissions themselves, the U.S. is still the largest emitter at just over 20% of all emissions globally. China currently contributes about 17% of global emissions. If you then look at the cumulative total emissions that have occurred since the start of the Industrial Revolution around 1800, then you’ll find China is way down; they only have contributed about 5% to these accumulated emissions, whereas Europe and the U.S. have contributed nearly 30% each to the total, accounting for nearly 60% between them. The importance of this is that the current climate change problem is the result of accumulated emissions of greenhouse gases, not of emissions in any one year. So, it matters enormously whether you look at how fast emissions are growing now, what the current emissions are, or what the total emissions are since the Industrial Revolution. As you change your time scale of view, which is what that sequence is doing, you get a different perspective. Countries like China, who are now going through a rapid development phase in their economies which is largely fossil-fuel powered, inevitably have rapidly growing emissions. If we look at the long term, China’s contribution looks much smaller because China is still at a relatively early stage of development trajectory in comparison to Europe and the U.S.
Another study issued by the CSIRO showed that sea-level rise is also at the upper end of the Intergovernmental Panel on Climate Change (IPCC) projections . Can you comment on this?
Not only sea level rise is at the upper end of IPCC projections, but also temperature rise. What we’re seeing with emissions is that they’re close to the upper end of the family of future scenarios developed by the IPCC prior to 2000. Six major scenarios were developed at that time, each making different assumptions about global economic and technological developments and hence about fossil-fuel CO2 emissions. We can now look at actual emissions since 2000, and how they relate to the predictions. What the emissions are actually doing is following fairly closely the higher-emission pair scenarios among the six, so that actual emissions are near the upper end of the predicted range. The same is true of sea level, and also with temperature. To me, this says two things. The first is that our efforts to control and reduce emissions through current international mechanisms have not had an effect on rates of emissions increase; we’re not seeing any discernable effects of mechanisms like the Kyoto Protocol on global emissions. This means that we have to try harder. The second big thing that these underestimations mean that the science is far from being alarmist up to this point—if anything, it has been conservative. The scientific predictions made in the mid to late ‘90s on increases in temperature and sea levels have been shown to be quite good, but conservative. That means we need to pay careful attention to both the trajectory and the error bars on future emissions and climate projections.
What is your opinion on the results of the recent United Nations Nairobi conference?
The Nairobi conference represented an agreement to keep talking which is good, but it didn’t take the critical next step which is an agreed formula for emissions controls and emissions targets stretching well beyond 2012, when the current version of Kyoto comes to an end. Also, this next-generation agreement has to include a wider group of countries than the current group of purely developed countries, therefore, it’s going to be important in some way that the major developing countries are included. Such an inclusive agreement will require sensitivity because it will need to respect the different stages that different countries have reached in their development cycles, and their consequent different levels of reliance on fossil fuels. I think it’s likely that economies like China and India will wean themselves off of fossil fuels much more quickly than the economies of the West did, partly because for most of the time those economies were developing, nobody had any idea that there was an issue with fossil fuel burning. Now that we do know, it’s going to be important to change trajectories. Even with that taken into account, there’ll still be a need for some differential treatment of countries who are fully developed and countries who are developing because of their vastly different stages of development. A related issue is the vast differences among countries in emissions per person, the per capita emissions. Developed countries, on the whole, have very high per capita emissions, anywhere between 3 and 5 tons of carbon (as fossil-fuel CO2) per person per year, whereas developing countries on the whole make much less, and in most cases are below the global average of about 1.1 tons of carbon per person per year.
Raupach, Michael et al., ESSP 2006 Open Science Conference, Beijing. 9-12 Nov 2006
Dr. Michael Raupach is a carbon-cycle scientist with Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra, as well as a participant in the Global Carbon Project.
Interview by: Gilles Prigent, Thanh-Tam Candice Vu