Blockbuster IPCC Chart Hints at Dust-Bowlification, But Report Is Mostly Silent on Warming’s Gravest Threat to Humanity

A USA Today (not IPCC) chart emphasizes the risk of drought in heavily populated areas.

The IPCC Special Report “Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX)” is now online.  I had seen the previous draft and the changes to it, so I knew that it was a big missed opportunity, as I explained here.

UPDATE:  Dr. Richard Klein offers a defense of the IPCC process in the comments of my previous post (here).

Even so, since the media hasn’t been spending much time connecting the dots between extreme weather and climate change, the report has garnered some headlines:

There is definitely some good material in the report (I’ll do a separate post on that).  We should all appreciate the hard work that a great many scientists put into this report.  I’ve been highly supportive of IPCC scientists over the years, pushing back against the attacks by the deniers and confusionists — even as I have been critical of the IPCC process that tends to water down even the most obvious conclusions.

For instance, the report states:

It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur in the 21st century on the global scale. It is very likely that the length, frequency and/or intensity of warm spells, or heat waves, will increase over most land areas.

Virtually certain means “99-100% probability” while very likely means “90-100% probability.”  Is there really as much as a 10% chance that the length, frequency and/or intensity of warm spells, or heat waves, will NOT increase over most land areas over the next 90 years?

Then we have this line:

It is very likely that mean sea level rise will contribute to upward trends in extreme coastal high water levels in the future.

C’mon guys and gals.  You couldn’t put a “virtually certain” on that?  Note that the sentence is already hedged with “will contribute” and “upward trends” and even the vague “in the future.”  Precisely how could mean sea level rise — even sticking with the lowball estimate from the 2007 report — have as much as a 10% chance of NOT contributing toward an upwards trend in extreme coastal high level waters sometime in the future.

So you can see the effect of the IPCC process that waters down even the most innocuous conclusions.  And by the way, since this is a 2011 report, it ought to base such statements on the recent literature of sea level rise, which is considerably higher than the 2007 estimate (see the discussion in “Scientists withdraw low-ball estimate of sea level rise“).

My biggest problem with the report remains the short shrift it gives to the vast literature on drought that I reviewed in my recent Nature article.  As I wrote, “Feeding some 9 billion people by mid-century in the face of a rapidly worsening climate may well be the greatest challenge the human race has ever faced.”

You can see from the chart above that USA Today (and Jeff Masters, who helped put it together) figured out that drought may be the biggest extreme weather danger in that it affects 5 heavily populated areas.

Reuters, in its story, states what should be obvious:

Droughts, perhaps the biggest worry for a world with a surging population to feed, were also expected to worsen.

The 29-page report itself has quite little on droughts, and the word “agriculture” appears only once in the main text, but it does have this blockbuster chart:

Figure SPM.5: Projected annual changes in dryness….  Changes in soil moisture (soil moisture anomalies, SMA). Increased dryness is indicated with yellow to red colors; decreased dryness with green to blue. Projected changes are expressed in units of standard deviation of the interannual variability in the three 20-year periods 1980-1999, 2046-2065 and 2081-2100. The figures show changes for two time horizons, 2046-2065 and 2081-2100, as compared to late-20th-century values (1980–1999), based on GCM [Global Climate Models] simulations under emissions scenario SRES A2 relative to corresponding simulations for the late-20th-century. Results are based on 17 (CDD) and 15 (SMA) GCMs contributing to the CMIP3. Colored shading is applied for areas where at least 66% (12 out of 17 for CDD, 10 out of 15 for SMA) of the models agree in the sign of the change; stippling is added for regions where at least 90% (16 out of 17 for CDD, 14 out of 15 for SMA) of all models agree in the sign of the change….

We can’t tell exactly how serious this is since they aren’t using a standard metric, like, say, the Palmer Drought Severity Index, and since the full report won’t be out until February!

But those large red patches around the global look pretty worrisome since they are where a great many people live and where a considerable amount of arable land is.  Indeed, the United States breadbasket looks to be headed for some very serious soil moisture drying in the second half the of the century if we stay anywhere near our current emissions path.

The IPCC has but one paragraph on this (plus the chart and a table):

There is medium confidence that droughts will intensify in the 21st century in some seasons and areas, due to reduced precipitation and/or increased evapotranspiration. This applies to regions including southern Europe and the Mediterranean region, central Europe, central North America, Central America and Mexico, northeast Brazil, and southern Africa. Elsewhere there is overall low confidence because of inconsistent projections of drought changes (dependent both on model and dryness index). Definitional issues, lack of observational data, and the inability of models to include all the factors that influence droughts preclude stronger confidence than medium in drought projections. See Figure SPM.5. [3.5.1, Table 3.3, Box 3.3]

The Table simply focuses on “Droughts in the context of food security in West Africa,” which is certainly important subject but only one of many, many areas around the world threatened by every-worsening droughts.

You would never know from this summary report that there is in fact a large literature just on the drying projected for the U.S. Southwest (which I reviewed here).  Heck, 3 years ago, the Bush Administration (!) released a US Geological Survey report that found:

The serious hydrological changes and impacts known to have occurred in both historic and prehistoric times over North America reflect large-scale changes in the climate system that can develop in a matter of years and, in the case of the more severe past megadroughts, persist for decades. Such hydrological changes fit the definition of abrupt change because they occur faster than the time scales needed for human and natural systems to adapt, leading to substantial disruptions in those systems. In the Southwest, for example, the models project a permanent drying by the mid-21st century that reaches the level of aridity seen in historical droughts, and a quarter of the projections may reach this level of aridity much earlier.

And there have been another half a dozen major studies covering the SW since then.

So yes the report was a missed opportunity to review this literature and highlight the  very real threat to food security.  The most comprehensive published literature review to date remains the must-read study from the National Center for Atmospheric Research, “Drought under global warming: a review,” which I discussed here.

21 Responses to Blockbuster IPCC Chart Hints at Dust-Bowlification, But Report Is Mostly Silent on Warming’s Gravest Threat to Humanity

  1. Leif says:

    Here is the deal. Would you prefer to bet the lives of your children for generations yet to come on a team of top international climatologists or FOX NEWS?

  2. Raul M. says:

    Well, in just my short time working with hydroponics, I’d rather not embarrass myself with grandeur. Hydroponics is fun though.

  3. Joan Savage says:

    Text in the executive summary is heavy on laying out a common vocabulary and set of categories. I hope the full report will provide examples to support the conceptual terms. The report expects effective responses to be at a national level.

    Consequently, a question I have about this report, Does the full report provide enough of a ‘toolbox’ for any country, including those of modest means, to frame an action plan?

  4. Paul magnus says:

    ” Is there really as much as a 10% chance that the length, frequency and/or intensity of warm spells, or heat waves, will NOT increase over most land areas over the next 90 years?”

    Well I think it’s a100% cause it has already happened and is currently happening and is 99% probably :) going to get worse!

  5. Paul magnus says:

    Is there going to be a similar report soon on ocean acidification?

  6. Raul M. says:


  7. Merrelyn Emery says:

    When does scientific cautiousness become global irresponsibility?

    As for those time frames, you can probably halve them. I know they are doing their best but surely now they should be building in a correction factor given that all previous predictions have been underestimates, ME

  8. Paul Magnus says:
    Experts Say Extreme Weather To Become The New Norm

  9. Paul Magnus says:

    Thousands of northern Nevadans fled their homes in the dark of night through roads cloaked with heavy smoke and rollicking orange flames as a massive and sudden wildfire consumed the Sierra Nevada foothills and spread down to the valley floor Friday.

    The blaze raged through more than 400 acres, claimed at least one life, injured several others, destroyed 20 homes and blanketed Reno and its suburban enclaves in a fiery curtain as violent winds sidelined firefighters and rescue helicopters.

  10. Paul Magnus says:

    So just wondering, have the insurance industry got similar figures on this and what are they?

  11. Sou says:

    Given that a drought is less than expected rainfall, if the drying is gradual then it becomes climate change rather than drought. (That is, it no longer fits the definition of ‘extreme event’.)

    Maybe that’s why Australia doesn’t rate a mention. It’s the driest inhabited continent already and large areas inland can’t get much drier than they are already. We do expect that the south-east and south west are going to continue to get hotter and drier, according to scientific projections.

    Will south west of Western Australia even be habitable in a few decades? Maybe Perth as a city will survive on desalinated water.

    Going by the figures in the Policymaker summary, the Murray-Darling – the main inland waterway and the main food producing area, will dry up unless it can keep flowing from tropical summer rainfall in the north. (The northern parts of the country may get wetter, and if enough rain falls on the right side of the Great Dividing Range, it will flow down the 2,740 km Darling and into the 2,500 km Murray – if there is enough of it to last the distance before evaporating.)

    I hope the full report covers this type of issue in more detail – not just for Australia, but around the world.

  12. Spike says:

    Prof Mike Hulme just been on BBC News saying you can’t link extreme weather to the pollution coming out of your tailpipe. Sadly he was the only scientist spoken to and for a few seconds only.

  13. Rabid Doomsayer says:

    It is not just drought and flood. Timing also matters. Recently the West Australian cereal crops were adversly affected by what would have been good rain weeks earlier. Rain too late has caused some crops to rot in the field.

    Secondly the IPCC report is a very conservative interpetation of conservative science which tends to be conservative. Science will fill in the blanks and narrow the range of uncertainty, but this can only be towards the it will be worse scenario.

    Finally our economic efficiency has often been at the price of a loss of resiliance. The cracks in the system have been papered over with the printing of vast amounts of money.

    Argentinia’s actual financial collapse barely caused a ripple, Italy has been in an unenviable position for many decades but now it threatens the world’s system.

  14. Jessen says:

    That’s an interesting statement for him to make, Mark, given that he doesn’t know any better than others exactly how close we are to risking cascading changes. The question is, at what rate did carbon accumulate back then, compared to this century under weak mitigation? And who “expects” with any confidence that changes of importance to humans and today’s ecosystems will remain gradual during the holocene (vs. the Permian)? Climatologists generally speak in global averages over decades, but last I checked today’s interglacial warming is not expected to be a linear process under anything like “business as usual”.

    And while we’re examining media coverage, NBC News (with one of the larger audiences) looked like it would really bring it home, but it descended into a kind of “we can adapt” theme (maybe we can adapt infrastructurei if we’re willing to pay, but ecosystem services and intensive agriculture?):

  15. Sou says:

    RD the same thing happened here in Victoria last summer. In what should have been the first decent season after the decade long ‘big drought’ we got the ‘big wet’ (Victoria’s wettest summer on record). In areas that weren’t inundated with the huge floods, fruit was getting mildew and other damage, pests and diseases from all the unseasonal humidity.

    That’s global warming for you.

    Maybe this year will be better. Good spring rains this year. Get in while the going is good before the next El Nino.

  16. Mulga Mumblebrain says:

    The ‘go to man’ in the UK for lightweight denialism. How he has not been savaged by his colleagues escapes me. The BBC disinformation sewer love him-he has the Right message.

  17. Toby says:

    I thought the interviewer rather dismissive of Hulme, but then you would wonder why they included him at all.

    The BBC were brought to book for this false “balance” last year – again, how quick they slip into old habits.

  18. Toby says:

    The IPCC in the end is a committee, and committees tend to gravitate to the lowest common denominator.

    Remember the definition of a camel – a horse designed by a committee?

    Or the story about the reporter who burst into his editor’s office in 1928

    “A lone man called Lindbergh has just flown the Atlantic!”

    The editor shrugged.

    “When a committee flies the Atlantic, we’ll print it”

  19. Colorado Bob says:

    Drought continues lowering Texas reservoirs

    FORT WORTH, Texas — The severe Texas drought continues to affect reservoirs that supply water to scores of municipalities.

    Some 96 percent of the state’s major reservoirs were below 60 percent capacity as of the end of October.

    The Texas Water Development Board says that average is the lowest since the agency began keeping records in 1978.

  20. Colorado Bob says:

    Scientists Developing Drought-Tolerant Maize for Hotter Future
    “There’s no free rides in this,” Marek says. “So, when you put a gene in or a characteristic in, you might take a little bit off the maximum production. But then, we don’t know what Mother Nature’s going to hold for that year.”

    This year, when Mother Nature was not kind to conventional maize, stay-green varieties produced bigger ears with more kernels than those without the trait. It’s a promising step, but it will take more work before these drought-hardy seeds are available for farmers. When they are, the benefits will reach far beyond the United States, Xu says.

    “Once we discover this drought-tolerant corn, this germplasm can be used throughout the world.”—134126378.html