by Judith Curry
At its recent Winter Meeting, The National Associated of Regulatory Utility Commissioners (NARUC) asked the following question: You’re Still Not Sure Global Warming is Real?
Last week, I participated in a Panel Discussion at NARUC. I hadn’t previously heard of NARUC. For some context:
Founded in 1889, the National Association of Regulatory Utility Commissioners is a non-profit organization dedicated to representing the State public service commissions who regulate the utilities that provide essential services such as energy, telecommunications, water, and transportation.
Our mission is to serve the public interest by improving the quality and effectiveness of public utility regulation. Under State law, NARUC’s members have an obligation to ensure the establishment and maintenance of utility services as may be required by law and to ensure that such services are provided at rates and conditions that are fair, reasonable and nondiscriminatory for all consumers.
As it turned out, my flight was cancelled owing to heavy snow on the east coast, so I participated by phone. It turned out to be pretty interesting, so I’ll reproduce as much as I can here.
Here is billing for the Panel:
You’re Still Not Sure Global Warming is Real?
Many news reports state that nearly 97% of climate scientists agree that manmade greenhouse gases are changing the world’s climate. Despite this, it isn’t difficult to find stakeholder organizations providing seemingly contradictory information about climate change and whether it is happening at all. Although NARUC members are economic regulators, recent federal initiatives to further reduce greenhouse gas emissions from power plants are placing this issue on our desks. With these rulemakings bringing new kinds of influence into State utility decision making, this seems like a good time to hear from the experts. We’ve invited two scientists to explain the latest scientific thinking about climate change and to answer the hardest questions we could put to them.
- Moderator Dr. Rajnish Barua – Executive Director, NRRI
- Panelist: Dr. Joe Casola – Staff Scientist and Program Dir. Sciences &Impacts, Center for Climate and Energy Solutions
- Panelist: Dr. Judith Curry – Professor, School of Earth and Atmospheric Sciences, GIT, and President, Climate Forecast Appl. Networks
For some background on Joe Casola, see his biosketch. I met Joe last fall at the Workshop on the Ethics of Communicating Uncertainty.
After some discussion with the moderator and Panel Organizer, we converged on 7 questions. We were each allotted 10 minutes for an opening statement, then a max of 2 slides to respond to each question.
In the interests of keeping this post manageable, I provide links to the ppt slides, but do not reproduce any of the figures in the blog post. Rather I focus on the narrative aspects of the discussion.
Opening statement: Joe Casola
The power point presentation is found here [NARUC Casola]. Excerpted below are the main narrative points:
The big picture:
- Carbon dioxide (CO2) and other greenhouse gases make the planet warmer
- CO2 is accumulating in the atmosphere
- The planet is warming
- Warming is best explained by humans’ emissions of CO2 and other greenhouse gases
- Future warming should be expected
Warming is best explained by our emissions:
- Magnitude and rate of warming is large (warmer than in last 400 years, at least; ice ages only +/- 5°C)
- Spatial and vertical pattern of warming matches what greenhouse gases “should” do
- Changes in other factors that drive climate (like the Sun) don’t explain warming
- Models can only replicate 20th century warming when greenhouse gases are included
What does this mean for regulators and the electricity sector?
- The BIG PICTURE is not a subject of debate within the scientific community
- There ARE many aspects of climate that are not completely understood, but do not undermine the BIG PICTURE understanding
- Best translation into a policy context = RISK MANAGEMENT approach
- Compared to other business and environmental risks, we actually have lots of information about climate change!
Opening statement: Judith Curry
The power point presentation is found here [NARUC curry]. The verbal narrative is provided below:
In my brief opening remarks, I’m going to focus on areas of uncertainty, disagreement, and confusion in the debate about climate change.
Confusion. Climate science is complicated and can be confusing. But the confusion is exacerbated by politicization of the science and also misleading communication by the media. The recent Sense of the Senate Resolution illustrates the problem.
- “Climate change is real and not a hoax” (98-1)
- “Climate change is real; and human activity significantly contributes to climate change.” (50-49)
The senate resolutions highlight the differences and confusion between the scientific versus the political definitions of climate change. The scientific definition states that climate change can be due to natural processes OR persistent human caused changes. The political definition is that climate change is caused by humans. The UN Framework Convention on Climate Change established the political definition in the 1990’s.
The political definition effectively defines naturally caused climate change out of existence. However, natural climate change versus human caused climate change is at the heart of the scientific debate. My remarks today will be directed at pointing out the importance of natural climate variability.
Disagreement. So, what do climate scientists agree on? Scientists agree that
- Surface temperatures have increased since 1880
- Humans are adding carbon dioxide to the atmosphere
- Carbon dioxide and other greenhouse gases have a warming effect on the planet
However there is considerable disagreement about the most consequential issues:
- Whether the warming since 1950 has been dominated by human causes
- How much the planet will warm in the 21st century
- Whether warming is ‘dangerous’
- And whether we can actually do anything to prevent climate change
Why do scientists disagree? There are a number of reasons:
- Insufficient observational evidence
- Disagreement about the value of different types of evidence
- Disagreement about the appropriate logical framework for linking and assessing the evidence
- Assessments of areas of ambiguity & ignorance
- And finally, the politicization of the science can torque the science in politically desired directions.
Uncertainty and disagreement drive scientific progress. However, when a scientific issue becomes politicized, and scientists attempt to speak consensus to power, then a scientific discussion of uncertainties is regarded as an undesirable political act.
Wicked vs tame problem. Another source of confusion is oversimplifying both the climate change problem and its solution. The UN Framework Convention and the Obama Administration seem to view climate change as a ‘tame problem’, where we clearly understand the problem and have identified the appropriate solutions.
I view the climate change problem very differently, as a ‘wicked mess’. A wicked problem is complex with dimensions that are difficult to define and changing with time. A mess is characterized by the complexity of interrelated issues, with suboptimal solutions that create additional problems.
You find what you shine a light on. The politicization of climate science, and effectively defining natural climate variability out of the public dialogue, has had a very unfortunate impact on the progress of climate science. Have you heard the story about the drunk searching for his lost keys under a streetlight, since that is the only place where he can see anything? Well something similar has been happening with climate science. You find what you shine a light on.
Motivated by the UN Framework Convention and the Intergovernmental Panel on Climate Change and government funding, climate scientists have been focusing primarily on greenhouse gases and to a lesser extent other anthropogenic factors. Other factors important for understanding climate variability have been relatively neglected, I have highlighted long-term ocean oscillations and solar indirect effects, since I think that these are potentially very important on decadal to century timescales.
Global surface temperatures. This figure shows the global surface temperature anomalies since 1850. We see a substantial temperature increase from 1910-1940, then a period of weak cooling from 1940 to the late 1970s, then a sharp increase since the late 1970’s until the 21st century when the temperatures are flat.
So what is causing the warming? The recent IPCC AR5 concluded: It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by [humans]. The best estimate of the human induced contribution is similar to the observed warming over this period. The IPCC does NOT have a consistent or convincing explanation for the large warming between 1910 and 1940, the cooling between 1940 and 1975, and the flat temperatures in the 21st century. Until the IPCC is able to explain these variations, I find their high confidence that humans have caused virtually all of the warming since 1950 to be unconvincing.
Last 350 years. So, how unusual is the warming since 1950? The longest temperature record in the world is the Central England Temperature, that goes back to 1660. You see a long term warming trend, but according to the Intergovernmental Panel on Climate Change, only the warming since 1950 is attributed to humans. Note in particular the sharp warming from 1690 to 1740 and 1820-1840. We can’t infer anything about global temperature variations from one location, but the Central England Temperature record serves to illustrate the magnitude of natural climate variability.
Last 2000 years. Using paleoclimate proxies such as tree rings and ice cores, attempts have been made to reconstruct the hemispheric temperature record for the past 2000 years. Unfortunately, these proxies can’t resolve variations shorter than 50 years. You may have heard of the hockey stick, made famous by Al Gore’s movie, which showed that climate for the past 1000 years was essentially flat, until the 20th century. However, recent research shows much greater variability and uncertainty in these paleoclimate reconstructions. Since 1600, you see a general warming trend. A warmer period around 1000 AD is evident, the so-called medieval warm period. There is a great deal of uncertainty in these analyses, leaving open the question as to whether the warming since 1950 has been unusual.
Hiatus. Lets take a closer look at the recent flat period, which is referred to as the warming ‘pause’ or ‘hiatus’. There was a big warm spike in 1998 from a super El Nino; since then the temperatures have been pretty flat. 2014 was a warm year, tied with several other years for the warmest in the record. Clearly there is a lot of year-to-year variability; why does this pause since 1998 matter? Well, the IPCC Fourth Assessment Report in 2007 stated that surface temperature was expected to increase by 0.2C per decade in the early 21st century. This warming has clearly not been realized.
Significance of the hiatus. The growing divergence between models & observations raises some serious questions:
- Are climate models too sensitive to carbon dioxide?
- Is modeled treatment of natural climate variability inadequate?
- Are model projections of 21st century warming too high?
Consensus view The issue of greatest concern is how the climate will evolve during the 21st century. There are two different perspectives on this. The first perspective is that of the Intergovernmental Panel on Climate Change. This figure is from the recent 5th Assessment Report, which projects continued warming. The IPCC cites ‘expert judgment’ as the rationale for lowering the projections (indicated by the red hatching), to account for the apparent oversensitivity of the models. With regards to the ‘pause’, the IPCC expects that it will end soon, with the next El Nino
Natural variability. The other perspective emphasizes natural variability, with the following implications for the future:
- Our understanding of circulation regimes in the Atlantic and Pacific Oceans suggest that the ‘pause’ will continue at least another decade, perhaps into the 2030’s
- Climate models are too sensitive to human forcing; 21st century warming will be on the low end of IPCC projections (or even below)
- Solar variations & volcanoes are a wild card. Some scientists are predicting solar cooling in the near term
- And finally, we can’t rule out unforeseen surprises. An example of an unforeseen surprise was the warming hiatus in the early 21st century.
Time will tell which of these two views is correct.
Implications. Some implications for utility regulators
- There is a great deal of uncertainty in our understanding of what has caused the 20th century warming and how the 21st century climate might evolve.
- • We need to prepare for surprises – including ‘cold’ ones
- • We need to stop treating climate change as a ‘tame problem’, and need to adopt a decision making framework, suitable for conditions of deep uncertainty, that seeks flexible, robust and anti-fragile policies
Questions
The powerpoint responses, along with my narrative response, are linked to following each question.
Question 1: Oceans rising? When the ice ages ended, sea level rose substantially over several thousand years. Is the more-recent resumption in sea level rise caused by human-caused global warming? Has human-caused climate change increased the threats to our coasts?
Question 2: Extreme weather events. Were recent extreme weather events made worse by man-made climate change? e.g, Hurricane Sandy. Is vulnerability to extreme weather events increasing because of human-caused climate change?
Question 3: Sea ice melting? Since satellite records began in 1979, Arctic sea ice at the end of summer has been retreating. But in Antarctica, the extent of the sea ice has been increasing recently. Are these changes due to human-caused global warming? Do scientists understand what is going on and why?
Question 4: Is the Earth warming or cooling? Some assert that the earth has not warmed in the last 16 years According to NOAA and NASA data, 2014 was the warmest year on record. How should we interpret recent temperature, relative to longer-term trends? Is the earth entering a cycle of global cooling due to a slowing in solar activity?
- .ppt response [Q4]
Question 5: Glaciers melting? Many (but not all) glaciers are melting, including Greenland and Antarctica! How confident are we that humans are causing some glaciers to melt?
- .ppt response [Q5]
Question 6: Are there benefits to CO2? Doesn’t CO2 help crops grow? How well do scientists understand the sources and sinks of CO2 in the atmosphere?
Question 7: Consensus? How much consensus exists in the scientific community that man-made greenhouse gases are changing the earth’s climate? What area of climate science would most benefit from additional research?
JC reflections
Overall I’m very pleased with the way this panel went. In terms of audience reaction, the panel organizer emailed this comment:
He and I have been to many, many NARUC conferences, and we agreed afterwards that your panel was the first time we saw the entire audience riveted and not having side conversations or working on their phones. One east-coast commissioner made a point of thanking me for organizing it and said it was the best session on the topic that he had ever heard. Finally, I must say that XXX was very pleased and commented that your panel was an example of what NARUC should encourage — thoughtful, smart discussion of important topics.
Another take on the Panel is described in this Climatewire post. I’ve also received a number of emails and tweets from people that were in the audience.
Preparing the 10 minute opening statement was quite a challenge. For a previous reference point, see these 10 minute presentations from Curry vs Trenberth. My own 10 minute presentation has evolved substantially (in a favorable direction I think).
A few words about Joe Casola’s presentation and responses to the questions. He gets very high marks from me. The presentation used figures from the IPCC (no indefensible alarmism such as Trenberth provided). Appropriate nods were given to uncertainty. And, as noted by Climatewire, his presentation included some effective metaphors. Further, he stuck to the science and gave no signs of ‘partisanship’ or advocacy.
I have to say it was a great pleasure to participate in this Panel with Joe Casola and the moderator and organizer from NARUC. It gives me some hope that an actual grown-up dialogue can be held on this topic.