by Judith Curry

The WG2 Report will be officially released on Monday. Here is what people are saying about a leaked version of the Summary for Policy Makers.

Donna LaFramboise has made available the latest version of the draft Summary for Policy Makers of the WG2 report that is currently being discussed in Yokohama (note: informed by Twitter that the SPM and full Report have just been approved).

The AR5 WG2 SPM has some startling differences and substantial additions relative to the AR4 version, and is in many ways a much better report. However, the AR4 WG2 Report is a low bar indeed, with the infamous Himalayan glacier error, and the substantial criticisms leveled by the IAC regarding treatment of uncertainty.

Chris Field, WG2 co-chair, has made this statement, excerpts:

The report itself is scientifically bold. It frames managing climate change as a challenge in managing risks, using this characterization as a starting point for two of the report’s core themes. The first is the importance of considering the full range of possible outcomes, including not only high-probability outcomes. It also considers outcomes with much lower probabilities but much, much larger consequences. Second, characterizing climate change as a challenge in managing risks opens doors to a wide range of options for solutions.

One of the things I like most about the report is that it combines cold, analytical realism, with a careful look at a broad range of possible solutions. This mapping of not only the serious and admittedly sometimes depressing “problem space” but also the exciting and potentially uplifting “solution space” allows the report to assess not only the impacts and challenges but also the opportunities and synergies. Truly, much of the material in the WGII report is as much about building a better world as it is about understanding serious problems.

Overviews

The best overview that I’ve seen so far is by Fred Pierce: New UN Report is Cautions on Making Climate Predictions. Excerpts:

[C]areful readers will note a new tone to its discussion of these issues that is markedly different from past efforts. It is more humble about what scientists can predict in advance, and far more interested in how societies can make themselves resilient. It also places climate risks much more IPCC cautious predictions firmly than before among a host of other problems faced by society, especially by the poor. That tone will annoy some for taking the edge off past warnings, but gratify others for providing a healthy dose of realism.

The draft agrees that “climate change will amplify existing stress on water availability in Africa” and will “very likely” reduce cereal crop productivity. But this time the discussion is not about how big or small those reductions might be, but on how African farmers might cope with less water, through terracing and agroforestry for instance.

Asia has fallen into a similar forecasting limbo. Last time, the IPCC warned that there would be less water in most Asian river basins and up to a billion people could experience “increased water stress” as early as the 2020s. This time, “there is low confidence in future precipitation projections at a subregional level and thus in future freshwater availability in most parts of Asia.” Last time the IPCC predicted “an increase of 10 to 20% in tropical cyclone intensities” in Asia. This time it reports “low confidence in region-specific projections of [cyclone] frequency and intensity.”

But it asks us to be grown-up about the uncertainties involved in what plays out when. “Responding to climate-related risks involves making decisions and taking actions in the face of continuing uncertainty about the extent of climate change and the severity of impacts in a changing world,” the draft report says.

The 2007 report was almost all about the impacts of climate change. Most of this report, and in particular most of the summary for policymakers, is about resilience and adaptation to inevitable climate change.

Central to that new take is setting climate change in a context of other risks, uncertainties and mega-trends such as poverty and social inequality, urbanization, and the globalization of food systems. What some call “climate exceptionalism” — the idea that climate change is something of an entirely different order to other threats faced by the world — has been rooted out. Here climate change is painted as pervasive, since nobody can avoid it wholly, but as usually only one among many pressures, especially on the poor.

Some nightmare scenarios are robustly defused. Past IPCC reports have warned that there might be as many as 50 million “climate refugees” around the world, who will flee drought, rising tides and spreading deserts. This report is set to dismiss that idea.

The report may irritate politicians in poor countries who look to blame climate change caused by the rich world for the ills of their people and want to demand reparations. But it may also dismay those who want to cite other factors to “prove” that climate change is never to blame. The world is more complicated, the scientists who prepared the draft conclude. The lesson of their report is that climate change will be implicated in a vast array of global ills, but it will rarely be the sole cause.

Spiegel Online has an article: UN Backtracks: Will Global Warming Really Trigger Mass Extinctions? Excerpts:

Global warming is said to be threatening thousands of animal and plant species with extinction. That, at least, is what the Intergovernmental Panel on Climate Change (IPCC) has been predicting for years.

But the UN climate body now says it is no longer so certain. The second part of the IPCC’s new assessment report is due to be presented next Monday in Yokohama, Japan. On the one hand, a classified draft of the report notes that a further “increased extinction risk for a substantial number of species during and beyond the 21st century” is to be expected. On the other hand, the IPCC admits that there is no evidence climate change has led to even a single species becoming extinct thus far.

The policy implications of this report are discussed in an article by Andrew Lilico entitled Climate change: the debate is about to change radically. Excerpts:

If the leaked draft is reflected in the published report, it will constitute the formal moving on of the debate from the past, futile focus upon “mitigation” to a new debate about resilience and adaptation.

The new report will apparently tell us that the global GDP costs of an expected global average temperature increase of 2.5 degrees Celsius over the 21st century will be between 0.2 and 2 per cent. To place that in context, the well-known Stern Review of 2006 estimated the costs as 5-20 per cent of GDP. Stern estimates the costs of his recommended policies for mitigating climate change at 2 per cent of GDP – and his estimates are widely regarded as relatively optimistic (others estimate mitigation costs as high as 10 per cent of global GDP). At a 2.4 per cent annual GDP growth rate, the global economy increases 0.2 per cent every month.

So the mitigation deal has become this: Accept enormous inconvenience, placing authoritarian control into the hands of global agencies, at huge costs that in some cases exceed 17 times the benefits even on the Government’s own evaluation criteria, with a global cost of 2 per cent of GDP at the low end and the risk that the cost will be vastly greater, and do all of this for an entire century, and then maybe – just maybe – we might save between one and ten months of global GDP growth.

Whereas previously the IPCC emphasised the effects climate change could have if not prevented, now the focus has moved on to how to make economies and societies resilient and to adapt to warming now considered inevitable. Climate exceptionalism – the notion that climate change is a challenge of a different order from, say, recessions or social inclusion or female education or many other important global policy goals – is to be down played. Instead, the new report emphasised that adapting to climate change is one of many challenges that policymakers will face but should have its proper place alongside other policies.

Our first step in adapting to climate change should be to accept that we aren’t going to mitigate it. We’re going to have to adapt. That doesn’t mean there might not be the odd mitigation-type policy, around the edges, that is cheap and feasible and worthwhile. But it does mean that the grandiloquent schemes for preventing climate change should go. Their day is done. Even the IPCC – albeit implicitly – sees that now.

Ramping up the alarm

So if you are a ‘climate realist’ and this sounds too good to be true, hang on, efforts are being made to ramp up the alarm.

The first article out of the post was an article by the Independent, with the alarming title: Official prophecy of doom: global warming will cause widespread conflict, displace millions of people and devastate the global economy. Richard Betts aptly tweeted that the Independent article was ‘cringeworthy.’

The WG2 has been amping up the alarm in its successive drafts, which has been discussed in posts by Donna LaFramboise and Paul Matthews. WG2 author Richard Tol is not happy how this is evolving, see articles by BBC and Reuters.

JC reflections

While I have yet to read the entire WG2 Report, the message that I am getting is there is a great deal of uncertainty in the attribution and future projections of climate change impacts, and that the threats on the timescale of the 21st century are not existential. The economic loss analysis discussed Lilico’s article reflects a stunning change from Nicholas Stern’s analysis; I suspect this will be the most hotly debated aspect of the WG2 Report.

The ‘message’ has shifted from documenting dire impacts, to finding solutions that integrate with broader societal challenges. This is a welcome change. Will the UNFCCC shift away from mitigation towards adaptation, and Andrew Lilico suggests? In light of the challenges of attributing and projecting climate change impacts, does the UNFCCC’s Warsaw Loss and Damage Mechanism make any sense? Richard Tol recently tweeted the following:

Bidding war in IPCC WG2 plenary: My country is more vulnerable than yours! We deserve a bigger share of the UNFCCC Adaptation Fund!

A logical conclusion from the WG2 Report seems to be that attribution of extreme damages and losses to AGW is not very useful. Regarding adaptation, a focus on the complex, interrelated issues facing developing countries and reducing extreme weather event vulnerability in developed countries is more fruitful than fostering a climate for corruption in terms of development and expecting that mitigation is feasible and will solve the world’s problems related to climate and extreme weather.

And where does all this leave climate science? Well this was the topic of the recent UK-US Workshop on Climate Science Needed to Support Robust Adaptation Decisions, see especially Part V Broadening the Portfolio of Climate Information (which includes my presentation).

Bottom line: I am intrigued to read the full WG2 Report, it sounds like they have done something different this time, and are moving in what I regard as the right direction.

UPDATE: my BBC Radio 5Live interview will be 7:30 a.m. UK time, 2:30 a.m. Atlanta time.