By breakfast tomorrow morning (NZ time), the IPCC will have released the final Synthesis Report of their Fifth Assessment on climate change. It will tie together the findings of three reports released over the last 13 months, covering the physical science of climate change (Working Group 1), vulnerability to climate impacts and adaptation (Working Group 2), and mitigation strategies to tackle climate change (Working Group 3). Having had time to mull over these earlier reports, we have a good idea of what the Synthesis Report might contain, so what makes this important?

 

Firstly we must acknowledge the scientific feat that this report represents: it pulls together five years of work by 830 authors, 1200 other contributors, draws on more than 30,000 pieces of research, and 3700 expert reviewers. That’s pretty damn epic.

 

Another unique feature of this report is the level of expectation surrounding it. In a month’s time, ministers from around the world will come together in Lima to agree to a draft text for the next global climate change agreement (to be settled in 2015 in Paris). The Fifth IPCC Synthesis Report will be the go-to text for policy makers seeking the science to inform and justify their policy positions going into these talks.

 

What makes the synthesis report even more interesting though is that it is released at the end of a week-long IPCC meeting in Copenhagen where government delegates have their last say on the contents of the report. While delegates cannot amend earlier findings and conclusions, they can ask for certain conclusions to be inserted into or eliminated from the draft Synthesis Report, shaping the way the findings will be communicated to the world.

 

So what will it tell us? Based on the previous three reports, and a leaked copy of the draft, here’s what we’re expecting…

• unequivocal evidence of climate change in every part of the world (each of the last three decades has been successively warmer than any preceding decade since 1850)
• greater than 95% likelihood that human agency is the dominant cause

• if greenhouse gas emissions continue rising at current rates, average projected global temperature increase of 2.6-4.8C by the end of the century, and at least half a metre sea level rise

• progressively greater risk of damaging and irreversible impacts as emissions continue

• projected impacts on crop yields, water availability, coastal flooding, disease, extreme weather, species extinctions…

• capacity for us to adapt will get progressively more difficult

• the internationally agreed 2C target is within reach if governments act together

• costs of combatting climate change will continue rising with ongoing delay.

What are the contentious bits?

Developing countries have a bone to pick around how these impacts should be addressed, given a disparity in historical contribution to the problem and uneven distribution of the impacts. “We are not all facing the same situation,” according to Sanjay Vashist of the Climate Action Network. “The IPCC has already predicted above 2 degrees C for South Asia, that means the disasters will be more threatening compared to other regions.”

Another sticking point may be the concept of a “carbon budget” included in this year’s reports. The IPCC worked out the amount of greenhouse gases that the world could emit stay within the 2 degrees target, finding that two-thirds of that budget had been used up by 2011, and that at current rates we’ll use the rest up in about 25 years. The inclusion of the carbon budget in the Synthesis Report has faced considerable opposition from political representatives from a number of countries, including India and the USA. India sees coal consumption as a key element of development and is in opposition to any potential restriction to this.

The inclusion or omission of the carbon budget in the Synthesis Report speaks to a broader question about how the IPCC will address the underlying truth that we simply need to stop extracting and burning fossil fuels. Essentially, unless our emissions peak within a decade or so and begin swiftly declining towards zero, staying within 2C is very unlikely, with pretty scary implications for the future.

Given the track record of UN meetings, where hours are devoted to negotiating market mechanisms such as carbon trading and carbon off-setting schemes, the need to bring an end to fossil fuel use (full stop) is a blunt reality, but one that I believe it is crucial for the IPCC to convey.

Whether the report speaks to this urgent and unavoidable need, or tip toes about the issue, could fundamentally impact the way the UN meetings unfold over the next twelve months. I hope they have the courage to stand by their conclusions and convey the urgency in no uncertain terms. Let’s see what the morning will bring us.

 

Written by Tarsh Turner