Posted on 1 November 2014 by Guest Author

by Simon Evans

On Sunday 2nd November, the Intergovernmental Panel on Climate Change (IPCC) will publish its latest synthesis report, distilling the latest knowledge on what UN chief Ban Ki-Moon has called the greatest threat ever faced by humanity.

The synthesis report will wrap up the IPCC's fifth assessment (AR5) of climate change. It draws together information from the IPCC's reports on the science of climate change, climate impactsand the ways climate risks can be addressed.

It takes a mammoth collective effort on the part of scientists, economists and policymakers to produce these IPCC reports. Is it worth it?

We've collected a range of views on the need for, and wider significance of, the IPCC's work. These suggest it remains a necessary but not sufficient part of the job of addressing climate change.

The synthesis report is necessary

Does the world need an IPCC, asks former IPCC chair and former scientific adviser to the UK government Bob Watson. "My answer would be absolutely yes," he says. "I think it's critically important the IPCC does routinely report back on what we know."

The synthesis report collects together scientific opinion on the technical and socio-economic aspects of the causes of climate change, the risks it poses and the options for adaptation and mitigation. It is unique in taking such a wide ranging and considered view of climate.

There's a huge amount of information to distill. The idea of the synthesis report is to take all that knowledge and to mould it into a coherent and accessible narrative.

The report is then checked, tweaked and approved line by line by government representatives, working with the scientists that wrote it. This gives the synthesis report added credibility, at least in theory, because all governments have signed off on what it says.

Denmark's minister of climate and energy Rasmus Helveg-Petersen told RTCC this process "eliminates the option of people inventing their own numbers… First we have to agree on the facts, then we can decide the course of action."

Government sign-off also means that the tone of the synthesis report is a reflection of how seriously governments take the risks of climate change. The language of the synthesis report is particularly significant when you consider that it is more widely read by policymakers than any of the IPCC's other reports.

The synthesis report is useful

So what do policy makers do with the synthesis report once they've chewed over its findings? There seem to be two primary uses: guiding policy choices and arguing for their adoption.

The synthesis helps us reach "informed and science-based" decisions, EU climate ministers said in an official statement this week. Ecuador's lead climate negotiator Daniel Ortega calls it a "poster child" for science-based policymaking and "one of the main drivers and shapers of the climate policy debate."

In his opening statement to this week's meeting, IPCC chair Rajendra Pachauri said:

"[The synthesis report] gives us the knowledge to make informed choices, the knowledge to build a brighter, more sustainable future. It enhances our vital understanding of the rationale for action - and the serious implications of inaction."

Seychelles ambassador and spokesperson for the Association of Small Island States (AOSIS) Ronny Jumeau tells Carbon Brief:

"?Science has guided AOSIS' positions at the UN climate negotiations? from the beginning, and unfortunately the information has steadily become more dire ever since. The IPCC plays a critical role in telling us where we need to be."

But where do we need to be? This is where things start to get a little more difficult, because different actors interpret the IPCC findings in different ways. Even though all governments agree to the text, they don't necessarily share a common understanding of what it means.

Ecuador's Ortega gives one example of this. He says:

"Due to its relevance, we must take care about the tone of the findings of the IPCC, which should not be understood as 'agreements'. One key example is the adoption by some actors of two degrees as the goal of the UN climate convention.

"This is just one IPCC scenario. Some countries believe it is already too risky and are making efforts to use 1.5 degrees as a point of reference. In fact, we should remember this is a global average which translates into much higher warming especially in some of the world's poorest regions."

Interpretations of the synthesis report vary even more widely, Watson says:

"Everyone uses the report. Those that want urgent action, like the EU, will say 'look, the IPCC has concluded there is no doubt human-induced climate change is occurring and there's no doubt that most of the effects will be negative'.

"They will use it to show there really is a need for action and that there are a significant number of technologies, if aligned with the right policies, that can cost-effectively reduce emissions as we try to stay within the two degree goal that was set in Durban and Cancun."

But use of the IPCC goes both ways, as Watson explains:

"The combination of the IPCC working group and synthesis reports will almost certainly be used by some to argue for action and by others to say do we know enough to act now."

There are already plenty of examples illustrating Watson's point. This week, Peruvian environment minister Manuel Pulgar-Vidal told Reuters that the synthesis report would show the need for urgent and ambitious action, while UK peer Matt Ridley referred to its section on the slowdown in global temperature rise in a House of Lords debate.

The synthesis report is not sufficient

These divergent interpretations of what the synthesis report is expected to say and what it means we should do start to illustrate the limits of what the IPCC can achieve. Ultimately, politics will decide whether the world takes meaningful global action on climate change, and securing agreement will take more than mere facts.

Greenpeace UK's policy director Doug Parr says:

"The idea of the IPCC as some kind of battering ram that will get those that object to climate action to agree… that thought process has been exhausted, I don't think it will. Let's not pretend a sixth IPCC assessment report will do that job because it won't.

"Our experience indicates it's the politics that needs unblocking rather more than the technical analysis. However passionately one is concerned about it and whatever briefings one gets [on the science] there is still a political intractability around this. The resistance is rooted in the practicalities of day to day politics."

The IPCC can put the facts on the table, Watson says, but the critical issues governments really have to work out are how to fairly distribute emissions rights and how to fairly share the costs. "So it's highly political," he says. "Very simply, are governments willing to act?"

Pachauri has said the task for policymakers of finalising a global climate agreement next year in Paris is formidable". But "it is not hopeless… the synthesis report shows that solutions are at hand".

The world has so far failed to reach a climate agreement despite a 25 years of negotiating and five IPCC reports, but that doesn't mean it has been a failure.

AOSIS spokesperson Jumeau says:

"We are still a long way from where we need to be because so many politicians have not had the courage to take the level of action needed.? On the other hand, we'd be in a much worse place if we did not have the science the IPCC provides.? As insufficient as the action to address climate change has been, we'd have taken even less action without the science.

"The latest IPCC report provides a roadmap for how to be successful in Paris. What is needed now is for leaders to take the wheel and, using the latest science available, bring us over the finish line."

Governments will try to progress along the road to Paris at a conference in the Peruvian capital Lima in early December. With the synthesis report coming just ahead of that meeting, the report's findings are likely to be closely considered by those tasked with agreeing a new global deal on climate change.