IPCC

The concentrations of carbon dioxide, methane and nitrogen oxides in the atmosphere are rising rapidly.  This rise has been caused by anthropogenic emissions.  The absorption of carbon dioxide by terrestrial vegetation and the ocean reduces the amount of CO2 left in the atmosphere by approximately 46%.  The absorption spectra and therefore also the greenhouse impact of these molecules are known from basic physical calculations and laboratory experiments.  The prevailing positive climate feedbacks strengthen the direct radiation effect and lead to a “climate sensitivity” of 3±1 °C.  The global warming is the result of the doubling of pre-industrial carbon dioxide concentration from 280 ppm to 560 ppm.  This knowledge is undisputed amongst climate researchers, it is independent from model simulations, and it is based on fundamental physical equations.  This is the reason for future considerable warming as a consequence of further greenhouse gas emissions.

I want to talk about the fact that climate change seems to finally have showed up on the public agenda.  You know that for a long time this was basically a conversation among us experts and maybe among some elitist politicians or NGOs.  However, it seems to have now appeared on the public agenda, and I want to talk more about where the public really is on global warming and, resulting from that, what the needs for communication are at this point.  I will discuss how difficult it is to talk about climate change and how well we have done today, what we have achieved and what is left to do, and I will take a pretty critical look at that. Finally, I will share the insights from this project that I have been involved in for the last three or four years on communicating climate change in a way that actually facilitates societal response to this problem -- not just communicating to get the word out, but to actually mobilize the public, which is, I think, the necessity now.

While it is true that I have been also a journalist, I should start by saying that I am not really good at communicating these issues, in particular the economics of climate change to journalists, and I am always getting in trouble with them, for example, when explaining how emissions trading works. Nevertheless, I will do my job here trying to explain the economics of climate change.

Because I am here to talk about the Millennium Assessment (MA), I changed the title of my presentation a little bit from “climate” to “environmental”. Climate is, of course, a major part of the environment.  If you look at assessments, they are really a booming business, a lot of people are doing them, and they are not science, but communications.  Here are some examples: The Dutch Concern for Tomorrow was one of the first in the late 1970s, the UNEP Global Environmental Outlook, the World Water Forum, the Arctic Climate Change Assessment, and the Dutch Sustainability Outlook.  The Dutch Sustainability Outlook actually uses the IPCC scenarios, implements them for the Netherlands and then asks policy makers: What is your “business as usual” scenario?  Compared to the policy makers, this assessment shows that the majority (i.e. 7050 of the public want a much more sustainable green scenario.  That assessment really showed a big mismatch between the public and the ideas of policy makers.

The new IPCC Working Group Reports have been published during the first half of 2007. They have been the basis for the Fourth IPCC Assessment Report, which was released at the end of 2007. The three Working Group Reports focuse on the physical base of climate change, the impacts on the ecosystem and human beings as well as adaptation and mitigation strategies and sparked off a wider debate about climate change.