The IPCC rebukes the climate doomsters. Will we listen?

Summary:  One of the major themes of the FM website is that The End of The World Will Not Occur as Scheduled.  Publication of the new IPCC report sparked yet another round of doomsterism, quite unrelated to its contents. Today we look at the IPCC’s description of the climate science consensus. They warn about the future, but not of an imminent apocalypse. Sometimes the news media explain this well; sometimes they feature doomsters without mentioning the consensus. Here we look at the IPCC report for guidance. It’s quite clear. The consequences of failure to convert to non-carbon-based energy sources will be severe for the second half of the 21st century; but we have time if we start now (which we should do anyway, for sound environmental and economic reasons).

World in our Hands
The world in our Hands



  1. Excerpts from the Summary: the bottom line
  2. Expressing confidence and probabilities in AR5
  3. How much warming during the next two decades?
  4. About the “pause” or “hiatus”
  5. Important things to remember about global warming!
  6. For More Information

(1)  Excerpts from the Summary: the bottom line

This posts discusses the report of  Working Group I, part of the IPCC’s Fifth Assessment Report: The Physical Science Basis: Chapter 11: Near-term Climate Change: Projections and Predictability. This is a draft, because the IPCC adjusts the scientists’ work to conform to the politicians’ desires (political logical always overrides scientific evidence).

This chapter assesses the scientific literature describing expectations for near-term climate (present through mid-century). Unless otherwise stated, “near-term” change and the projected changes below are for the period 2016–2035 relative to the reference period 198 6–2005. …

The projected change in global mean surface air temperature will likely be in the range 0.3–0.7°C (medium confidence). …

It is more likely than not that the mean global mean surface air temperature for the period 2016–2035 will be more than 1°C (1.8°F) above the mean for 1850–1900, and very unlikely that it will be more than 1.5°C (2.7°F) above the 1850-1900 mean (medium confidence).

(2)  Expressing confidence and probabilities in AR5

What makes the IPCC’s work science, not religion or organized ignorance, is that they state their conclusions in terms of uncertainty (comments to the climate posts on the FM website show how discovering this freaks out activists). From footnotes 1 and 2:

The level of confidence is expressed using five qualifiers: very low, low, medium, high, and very high.

In this Report the following terms have been used to indicate the assessed likelihood of an outcome or a result:

Understanding uncertainty make it science
  • Virtually certain 99–100% probability,
  • Extremely likely: 95–100%,
  • Very likely 90–100%,
  • Likely 66–100%,
  • About as likely as not 33–66%,
  • Unlikely 0–33%,
  • Very unlikely 0–10%
  • Exceptionally unlikely 0–1%,
  • More likely than not >50–100%, and
  • Extremely unlikely 0–5%)

(3)  How much warming can we expect to see during the next two decades?

Overall, in the absence of major volcanic eruptions and, assuming no significant future long term changes in solar irradiance, it is likely (>66% probability) that the GMST {global mean surface temperature} anomaly for the period 2016–2035, relative to the reference period of 1986–2005 will be in the range 0.3°C – 0.7°C {0.5°F  – 1.3°F} (expert assessment, to one significant figure; medium confidence).

However, the implied rates of warming over the period from 1986–2005 to 2016–2035 are lower as a result of the hiatus: 0.10°C–0.23°C per decade, suggesting the AR4 assessment was near the upper end of current expectations for this specific time interval.

See Figure 11.9 — not the apocalypse. The lower end of this forecast sees almost no warming during the next 22 years. The upper end of the range requires a large acceleration from the trend of the past decade or two.

IPCC AR5: WG1, figure 11.9
IPCC AR5: Working Group 1, figure 11.9, panel 1


IPCC AR5: working group 1, figure 11.9
IPCC AR5: Working Group 1, figure 11.9, panel 2


(4)  About the “pause” or “hiatus”

Whether from ignorance or mendacity, climate activists continue to ignore climate scientists’ work about the pause in warming since roughly 1998.  For a prime example see “Who Created the Global Warming ‘Pause’?“, Chris Mooney, Mother Jones, 7 October 2013 — “How climate skeptics and the media — with a little inadvertent help from scientists themselves — forged a misleading narrative.”  Not only did Mooney ignore the large literature describing the pause, he mocked the IPCC’s summary:

If the “pause” was just the result of statistical selectivity rather than a robust trend, why wasn’t the IPCC saying so? Instead, the scientists’ own words seemed to suggest that there really was a global warming slowdown, and that the scientific community didn’t really understand it.

It does not occur to Mooney that the IPCC said this because that’s what the literature says. Here’s one of the many similar passages from AR5 about the pause, from Chapter 11:

6) Over the last two decades the observed rate of increase in GMST {global mean surface temperature} has been at the lower end of rates simulated by CMIP5 models (Figure11.25a). This hiatus in GMST rise is discussed in detail in Box 9.2 (Chapter 9), where it is concluded that the hiatus is attributable, in roughly equal measure, to a decline in the rate of increase in effective radiative forcing (ERF) and a cooling contribution from internal variability (expert judgment, medium confidence).

Today’s models suggest that the pause might continue for two decades. If that happens, the activists crying “wolf” (e.g., attributing any severe weather to global warming, even when scientists and history say otherwise) might discredit not just themselves but climate science — and perhaps even science.

(5) A few important things to remember about global warming

While cheering for their faction of scientists, laypeople often lose sight of the big picture — the key elements for making public policy about this important issue.

(a)  The work of the IPCC and the major science institutes are the best guides for information about these issues.

(b)  The world has been warming during the past two centuries, in a succession of warming, cooling, and pauses. Since roughly 1950 anthropogenic causes have been the largest driver. Warming paused sometime in 1998-2000.

(c)  There is a debate about the attribution (causes) of past warming — which probably varied over time — between natural drivers (e.g., rebound from the Little Ice Age, solar influences) and anthropogenic drivers (eg, CO2, aerosols, land use changes). Other that that stated in #3, the IPCC’s reports make few claims about attribution of climate activity, as this remains actively debated in the literature.

(d)  There is an even larger debate about climate forecasts, both the extent of future CO2 emissions and the net effects of the various natural and anthropogenic drivers.

(e)  For the past five years my recommendations have been the same:

  1. More funding for climate sciences. Many key aspects (eg, global temperature data collection and analysis) are grossly underfunded.
  2. Wider involvement of relevant experts in this debate. For example, geologists, statisticians and software engineers have been largely excluded — although their fields of knowledge are deeply involved.

(f)  Posts about preparing for climate change:

(6) For More Information

(a) Reference Pages about climate on the FM sites:

(b)  Other posts in this series about global warming:

  1. Lessons about global warming from Alaska, 9 January 2013
  2. Secrets about global warming that you must not know, least they ruin the narrative, 22 January 2013
  3. Hidden news about our weather in July: experts tell us what even well-informed people do not know., 8 August 2013

(c)  Posts about the larger aspects of the debate about global warming:

  1. Experts now run the world using their theories. What if they fail, and we lose confidence in them?, 21 June 2013
  2. Tell noble lies for America’s salvation!, 31 July 2013




8 thoughts on “The IPCC rebukes the climate doomsters. Will we listen?

  1. Thank you for posting sensible graphical chart/data. This is the way all these data should always have been displayed (and were NOT). Yes, real scientists include the uncertainty in their modeling with their narrative/arguments. Again, scientists who do not do this, and seek public attention, are not usually to be trusted (they have hidden agendas: money, or “moral superiority” motivations; i.e. NOT science.)

    Note: I do modeling in chemistry for a living.


    1. My impression from past posts was that your policy recommendation in this area was limited to “more funding for climate research.” Yet in your summary above you state: “The consequences of failure to convert to non-carbon-based energy sources will be severe for the second half of the 21st century; but we have time if we start now (which we should do anyway, for sound environmental and economic reasons).” That sentence suggests that your policy recommendation with respect to global warming is more like “start converting to non-carbon-based energy sources now.” How is that position different from the “alarmist” or “activist” position?


    2. nnoxks,

      “How is that position different from the “alarmist” or “activist” position?”

      That’s an incisive question! The energy recommendations have been discussed on energy posts (I tend to excessive compartmentalization).

      As shown by much research (e.g., the 2005 Hirsch report, the closest thing the US has to an energy strategy):

      * we have little in the way of alternatives to gasoline at this time.
      * we have few alternatives to baseline electric generation other than fossil fuel — with the exception of nukes, and events in Japan have shaken my confidence in them.
      * development of alternatives is proceeding at a snail’s pace, esp compared with what we need (e.g., government funding for projects like the Polywell are little but pocket lint), so we’re almost at the start line.

      Therefore shifting from fossil fuels is a multi-decade, probably a multi-generational one. The effect on CO2 emissions will be distant. Therefore the only alternatives are some combination of:

      * hope that the scientists forecasting low temperature rise are correct,
      * start mitigation programs (much of which are necessary anyway, such as preparation of the US East coast for rising sea levels (necessary anyway to prepare for normal hurricane impacts)
      * crash fund climate research — rather than the underfunded, uncoordinated work done today — to better predict and prepare,
      * crash fund energy research,
      * push use of alternatives (I don’t expect much from this),
      * take steps to crash the global economy — the alarmists recommendation, which I reject.

      THis is oversimpliefied, but seems more or less correct.


    1. Winston,

      I am sure you realize that this article provides not a shred of evidence that climate change is in effect, let alone of anthropogenic causes.

      These stories are commonplace in history. In the past others were blamed. Commies, witches, the villagers downstream, those threatening people of the other religon.

      I esp like this part:

      The tribunal concluded that the impacts felt by the coastal fisherfolk community of Bangladesh is the direct consequence of climate change and resulted in some important recommendations for action, including that the Government of Bangladesh takes immediate measures to reduce vulnerability to the projected impacts of climate change, such financial assistance and a social safety net for the people of climate-impact zones.

      Nice to know that the local tribune did not say it was just life, go home.


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