Thursday, April 24, 2014

Before we forget: IPCC working group 3 report published

In case you have not noticed, the IPCC has published the report of Working Group 3, the last in the trilogy of its state-of-the-art Fifth Assessment. There seems to be an established routine in media coverage which goes by the rule that most attention should be paid to working group 'number one' (covering the physical science basis), less to 'number two' (impacts, adaptation, vulnerability), and well you guessed it, even less to 'number three' (mitigation). But the last one, published last week, seems to have led to some behind the
scenes wrangling between scientists and government representatives which ended with the latter carrying the day. According to one of the scientists on the panel, David Victor, some governments didn't like the inclusion of information which attributes emissions to countries (see also here for an assessment of the episode). This may be understandable but makes a mockery of the principle of the IPCC's slogan that it provides policy-relevant, yet policy neutral information to governments. In this instance governments simply got rid of information which did not suit them.

Another aspect caught my attention. This is the shift of emphasis (or lack thereof) from AR4 to AR5. Below I show two word clouds, taken form the Summary for Policymakers documents. On top is the latest report, below the previous:

The top frequency words are much the same in both SPM documents: emissions, mitigation, energy.

In contrast, both WG1 and WG2 have seen a shift in emphasis. WG1 in the 2007 report emphasised sea level, ice, and warming but in 2013 gave more prominence to the words confidence, mean and surface. Likewise, WG2 shifted from a focus on projected, impacts, and increased to adaptation, risks and confidence. Confidence has gained in both Working groups.

What does this tell us? Perhaps not much. Simple frequency lists are too crude to convey nuanced meaning. However, they are often a good indication of what is emphasised in a text (provided it is of sufficient length). Assuming this is the case I would venture the idea that WG1 and WG2 have re-assessed their previous reports (without explicitly saying so) whereas WG3 has not. It sticks to the same message as before.

If we believe the Economist, the message of WG3 is that massive reductions of CO2 emissions are needed if the world wants to stay within the 'safe' boundary of 2 degrees Celsius of warming. Because of rapidly increasing rates of emissions over the past decade, this goal seems difficult to achieve. However, and this is where it gets interesting, the report sees a chance of achieving the target by reinforcing the efforts of expanding renewables and nuclear for energy generation, up to 80% (and by developing carbon capture and storage). The costs of doing so are projected to be moderate, costing just 0.06% of annual GDP worldwide by the year 2100. 'These numbers are preposterous', says the Economist: 'Germany and Spain have gone further than most in using public subsidies to boost the share of renewable energy (though to nothing like 80%) and their bills have been enormous: 0.6% of GDP a year in Germany and 0.8% in Spain. The costs of emission-reduction measures have routinely proved much higher than expected.'

Should Working Group 3 have known better? After all, 13 of its 113 drafting authors are from Germany, the highest proportion. 9 come from the USA, 5 from India, 3 from China, Brazil, and the UK.


Hans von Storch said...

Ich fand diesen Bericht über die Interaktion von Wissenschaft und Politik interessant, weil authentisch, von innen:

Ich denke, es kann gut sein, daß dies eine Besonderheit von WG II, im Gegensatz zu den WGs I und II ist.

@ReinerGrundmann said...

If this is the case I wonder what the reasons are for the difference. I seem to remember that oil exporting countries were trying some tactics in early reports within WP2. But this seems to have subsided.

WG2 is about impacts and perhaps this has created an incentive among governments to state the potential impacts in their fullest range, especially as there could be some kind of compensation.

WG3 talks about mitigation and attributes quantities of emissions which is against the interests of some governments.

Has this kind of government manipulation happened in previous reports of WG3? If not, why now?

@ReinerGrundmann said...

Sorry, I meant

"oil exporting countries were trying some tactics in early reports within WG1."

@ReinerGrundmann said...

Here is an inside story from an environmentalist, covering the early 1990s

Not sure if similar accounts have been produced for later reports, or from different political viewpoints.

@ReinerGrundmann said...

Ottmar Edenhofer, the co-chair of WG3 has written a letter to the Economist which is published in its latest edition:

SIR – You described the estimated costs of mitigation in a report by the Intergovernmental Panel on Climate Change as “preposterous” for being too low (“Another week, another report”, April 19th). But the cost of 0.06 percentage points of economic growth that you quoted is a reduction in the annual average consumption growth rate over the 21st century in stringent mitigation scenarios. This should not be compared with absolute reductions in economic output or consumption in a particular year. Indeed, the reductions in the rate of consumption growth correspond to median consumption losses of 1.7% by 2030 and 3.4% by 2050, relative to what would otherwise happen.

You argued that the “costs of emission-reduction measures have routinely proved much higher than expected”. In the report the IPCC highlighted that cost estimates depend on a variety of assumptions, including the availability of relevant technologies and co-ordinated international action. These can indeed increase the costs substantially, as laid out in a comprehensive table in the summary for policymakers.

The IPCC does not specify the feasibility of achieving a certain long-term climate-policy goal, but identifies the technological, economic and institutional requirements for achieving alternative goals under different socioeconomic conditions from a large body of scientific literature. Technological development, breakthroughs and human ingenuity will change these assumptions over time.

That is the reason why these models should not be used as prediction machines, but as “living maps”, drawn up by scientists with the most recent evidence available to help policymakers navigate safely through a widely unknown landscape.

Ottmar Edenhofer
IPCC Working Group III
Potsdam, Germany

The contentious issue about reduced economic growth (0.06% pa.) is addressed in an oblique way (emphasised above) which is not immediately clear (at least not to me, as a non-economist). Maybe someone can help?