As greenhouse gas emissions continue to grow and the glaciergate debate fades, the IPCC is gearing up for another report, another round of controversey. It will take great care testing the science; will its critics? And what's the future of transport?

The story goes like this: Following publication of the 4th Assessment Report in February 2007 and the completion of the Special Report on Renewable Energy, the member countries of the Intergovernmental Panel on Climate Change agreed in April 2008 to undertake a 5th Assessment Report (AR5). It's intended to be released in February 2011 after the final review process has been completed. As with all well-managed organizations, the IPCC is simultaneously under-going an independent review process to ensure it effectively meets the objectives as outlined when it was first established through the United Nations over two decades ago.

Whilst greenhouse gases (GHGs) continue to be released at ever-increasing levels around the world, considerable additional scientific analysis is aiming to:
a) enhance the understanding of the physical sciences that have shown how increasing GHG concentrations are affecting our changing climate;
b) assess the needs for, and costs of, adaptation of both natural and built environments to reduce their vulnerability as a result of anticipated climate change impacts; and
c) develop and evaluate additional cost-effective mitigation methods and technologies to help reduce annual total GHG emissions.
The AR5 will report on all these latest research findings in its three reports on Climate Science (14 chapters), Adaptation (30 chapters) and Mitigation (16 chapters) based on a structural content that was scoped out during international deliberations in April 2009.

From over 3 000 nominations received from governments and industry, around 800 authors have been recently selected by the IPCC Bureau to provide a wide range of expertise for each chapter, to give geographical spread particularly including active contributors from developing countries, and to ensure gender equity. Detailed lists of the chapters and authors, many new to the IPCC process, are available at www.ipcc.ch. New Zealand is, as usual, well represented including:
•    Climate Science – Jim Renwick (NIWA), glaciologist Tim Naish (Antartic Research Centre) and David Wratt (NIWA as Review Editor);
•    Adaptation – oceonologist Phil Boyd (NIWA), health scientist Alistair Woodward (Auckland University), as well as Andy Reisinger (Victoria University) coordinating the Australasia chapter that also includes Paul Newton (AgResearch),  Andrew Tait (NIWA) and Review Editor Blair Fitzharris (Otago University); 
•    Mitigation – Harry Clark (AgResearch) in the chapter on Agriculture, Forestry and Land Use and myself coordinating the Transport chapter.
So what will the AR5 achieve? It aims, as is always the case for IPCC reports, to bring together all the latest scientific knowledge (including from the social sciences) into one place and to synthesise the knowledge gleaned from thousands of published references into a form useable by policy makers.

It aims to put greater emphasis on regional assessments than was done in the AR4 and there will be closer scrutiny of the various climate, scenario and economic models often being quoted in the literature. Overall goals of the AR5 include to:
•    assess and report state-of-the-art knowledge wherever there is reasonable certainty as measured by strong scientific consensus;
•    present an unbiased discussion of both sides of any debate in the published scientific literature where there is greater uncertainty and possible disagreement over interpretations of evidence; and
•    identify any gaps in the literature that will need further research investment.

The IPCC does not advise on policy measures. It simply presents the current knowledge to the best of the ability of the authors and following a unique, three-stage review process whereby hundreds of experts and government officials make thousands of comments on the different drafts, each comment made needing to be addressed by the report authors.

The 8-10 page Summary for Policy Makers has to be accepted by consensus, sentence by sentence, by usually over 150 national negotiating teams, a laborious but effective process which usually takes several days. The summary reports are written in a format that is easily understandable by everyone and in an unbiased fashion, although a few climate skeptics claimed otherwise through the media for the AR4.

Incidentally, it's interesting to note that following the world headlines last year over the East Anglia University E-mails on climate science that were illegally hacked and then reported somewhat erroneously by the media, the scientists involved have been totally exonerated by two independent panels. But how poorly was that news reported by comparison? The orchestrated campaign to undermine the climate science in 2009 leading up to the Copenhagen climate change meeting was largely successful by creating confusion in the minds of the public and policy makers alike.

The instigators, together with the media, however now have a lot to answer for. Debating the science is essential, and always has been. But any counter arguments need to also be backed up by rigorous scientific analysis which has rarely been the case to date.

Certainly the IPCC will endeavour to achieve even greater fairness and accuracy in its reporting of the scientific debate than ever before. But no doubt, somewhere in around the 2500 pages to be written by over 800 authors, some errors will inevitably slip through even this most stringent review process. The key messages won’t change but the headlines might.

So what will be in store for my colleagues and I when compiling the Transport chapter? We know that GHG emissions have been growing fastest in this sector in spite of more efficient engines, improved freight management, new air traffic control techniques, more high speed electric trains etc. But which technologies will become common by 2030 and further out is not easy to assess.

Electric road vehicles are being developed fast, linked with the possible advent of intelligent grids, smart meters and distributed energy systems that can also integrate variable renewable energy technologies such as solar and wind at high levels of penetration. But what of hydrogen fuel cell vehicles that were always in the news only three or four years ago but now seem to have gone “out of fashion”? And what of automated driverless pods, community-owned cars, electric cycles such as the NZ-made Yike Bike, and the future date for reaching peak cheap oil (noting that the world will most probably not run out of liquid transport fuels but that the cheapest sources are rapidly being used up)?

Maybe by 2030 all inhabitants of the planet may have the right to mobility, but not the right to own a car. What impact on GHG emissions might such technical and societal changes have and what assumptions can scenario modelers use for such a transition of the energy sector? It is clear that for several reasons we can no longer keep running around in hugely energy inefficient vehicles as we have done for a century or more. Maybe by the time the AR5 is published in 2014 the research outputs as reported in the scientific literature will provide some more clues as to what the transport future may hold.

The IPCC will endeavour to provide unbiased analysis to assist future Ministers of Transport, Energy, Economic Development, Trade, Health, Employment and Climate Change make appropriate decisions, based on the best available scientific information.