The recent Senate hearing was a sad example of what passes for debate and deliberations by the U.S. Senate.  In any event, it provides an interesting case study of why the U.S. cannot bridge the partisan divide and figure out how to deal sensibly with the climate change issue.

In case you missed it, the Chair of the Senate Budget, Sheldon Whitehouse, has immortalized on youtube his questioning of me at the end of the Hearing:  Chairman Whitehouse Presses GOP Witness in Budget Hearing on Climate Change and Insurance Markets.

I expected SW to go after me, which he has often done to Republican witnesses.  In my written testimony, I added a paragraph at the end of my biosketch to defuse any accusations of being in the pocket of ‘big oil.’  When SW introduced the witnesses, he thanked each one and said he was looking forward to their testimony – including the other Republican witness.  In introducing me, he simply stated my name and my positions. The writing was on the wall from the very beginning of the Hearing.   However, I did not expect the inanity that ensued.

It seems that Senator Whitehouse thought that his grilling of me was some sort of magnificent ‘takedown’:  mischaracterizing things that I had written over a decade ago, out of context references to my use of alarmist trigger words “hoax” and “corrupt” in interviews and obscure blog posts, unpublished graphs that I have never seen before, words of ‘wisdom’ from Exxon in the 1960s, etc.

Apart from the issue that almost none of this had anything to do with my testimony, and much of the time, I had no idea what he was talking about, he gave me about 30 seconds to respond to each of these, saying that I could respond later in writing.  The day after the Hearing, his staffer emailed me with follow-up questions from Senator Grassley (see my responses:  Judith Curry response to Senator Grassley questions) and that “I will also be sending you a transcript of your remarks from the hearing in the next few days, to make minor edits to” – I have yet to receive this transcript.

In any event, that doesn’t sound like I will really have a chance to respond in the Congressional Record in a meaningful way, as promised several times by Senator Whitehouse. So I am responding here on my blog,  to show how pointless such behavior is in the Halls of Congress, where serious issues should be debated in a serious manner.

My 2014 Congressional Testimony

SW brought up my 2014 Testimony before the Senate Committee on Environment and Public Works, which compared statements made by the IPCC AR4 (2007) with the IPCC AR5 (2013), which led me to conclude that the AR5 presented a weaker case for anthropogenic warming than did the AR4.

SW read off my summary bullet points without mentioning the substantial documentation I provided in terms of direct quotes from the AR5, and then proceeded to attempt a refutation of my 2014 Testimony by mischaracterizing my statements and bringing up recent observations, e.g. that the Antarctic sea ice was currently at a record low level.

Here is the text from my 2014 testimony that includes direct quotes from the IPCC AR5:

“[T]he rate of warming over the past 15 years (1998–2012) [is] 0.05 [–0.05 to +0.15] °C per decade which is smaller than the rate calculated since 1951 (1951–2012) [of] 0.12 [0.08 to 0.14] °C per decade.”

“It is very likely that the mean rate of global averaged sea level rise was 1.7 [1.5 to 1.9] mm yr–1 between 1901 and 2010, 2.0 [1.7 to 2.3] mm yr–1 between 1971 and 2010, and 3.2 [2.8 to 3.6] mm yr–1 between 1993 and 2010. It is likely that similarly high rates occurred between 1920 and 1950.”

“It is very likely that the annual Antarctic sea ice extent increased at a rate of between 1.2 and 1.8% per decade between 1979 and 2012.  “There is low confidence in the scientific understanding of the observed increase in Antarctic sea ice extent since 1979, due to the incomplete and competing scientific explanations for the causes of change and low confidence in estimates of internal variability.”

SW asks how these conclusions have held up over time.  The historical temperature and sea level data remain as they were (well, for the most part), and the slow but irregular creep of warming has continued.

Senator Whitehouse used the recent record low in Antarctic sea ice extent as a refutation of statements in my 2014 testimony. The IPCC AR5 statements about Antarctic sea ice that were cited in my 2014 Testimony have generally stood the test of time.  Here is the text from the IPCC AR6 WGI Report (Section 2.3.2.1.2):

“AR5 (2013) reported a small but significant increase in the total annual mean Antarctic SIE [sea ice extent] that was very likely in the range of 1.2–1.8% per decade between 1979 and 2012 (0.13–0.20 million km² per decade) (very high confidence), while SROCC (2019) reported that total Antarctic sea ice coverage exhibited no significant trend over the period of satellite observations (1979–2018) (high confidence). SROCC noted that a significant positive trend in mean annual ice cover between 1979 and 2015 had not persisted, due to three consecutive years of below-average ice cover (2016–2018). SROCC stated also that historical Antarctic sea ice data from different sources indicated a decrease in overall Antarctic sea ice cover since the early 1960s, but was too small to be separated from natural variability (high confidence).”

Nowhere in the IPCC reports do they attribute any decrease in Antarctic sea ice extent to human caused warming.

Discrepancies between climate model projections and observations

During the Hearing, I was presented with a figure purporting to prove that climate models in 2004 had accurately predicted the global average temperature since then.

I did not recognize that particular figure, but I knew that the CMIP3 models used in the 2007 IPCC AR4 were found by the AR5 to have overpredicted the temperatures for the period 1999-2012. I also knew that the CMIP3 climate models were heavily tuned to the historical temperature record (which explains the good agreement prior to 2004).  I subsequently discovered that this figure was published in a blog post with no clear description of exactly how the model-observation comparison was made.

Here is the relevant figure from the IPCC AR5.  Figure 11.25 compares climate model projections with observations of global surface temperature anomalies through 2012.

Figure 11.25 shows that near-term climate projections for the period 1999-2012 were much warmer than the observed temperatures, with several years dropping below the 5-95% envelope of the climate model simulations.

With regards to the CMIP3 simulations used in the blog post and diagram presented by Senator Whitehouse, the IPCC AR5 has this to say:

“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 [CMIP3 models] was near the upper end of current expectations for this specific time interval.”

Ed Hawkins is the IPCC author who prepared Figure 11.25.  He updated the Figure with temperatures through 2021.  This later period included the extremely warm temperatures associated with the super El Nino in 2016.  The year 2016 barely made it to the midpoint of the climate model range; compare 2016 with 1998 (a previous super El Nino), which slightly exceeded the upper boundary of the 5-95% range.

Trigger words:  corruption and hoax

The most inane part of the questioning was challenging me on my use of two trigger words for climate change alarmists – “corrupt” and “hoax.”

SW stated:  You’ve accused the IPCC of corruption.  Do you stand by that accusation? He did not provide a direct quotation. I have no idea exactly what he is referring to, even after a Google search of the relevant words.

In a 2010 interview for Discover Magazine, I made the following statement:

“There is a substantial level of public interest in investigating the issues raised by Climategate. These issues include: wanting an assessment of the reliability and accuracy of the historical and paleotemperature records/reconstructions, wanting an assessment of whether the IPCC was corrupted and whether their conclusions are reliable and can be trusted as the basis for international carbon and energy policy; and whether there are some “bad apples” in the climate research community that need to be weeded out in the sense of not being in positions of responsibility as journal editor, IPCC lead author, administrator.”

This statement was subsequently exaggerated inappropriately in a 2010 Scientific American profile on me:

“Few scientists would claim the IPCC is perfect, but Curry thinks it needs thoroughgoing reform. She accuses it of “corruption.” “I’m not going to just spout off and endorse the IPCC,” she says, “because I think I don’t have confidence in the process.” “

A 2012 interview with oilprice.com made the following statement, which correctly reflects my concerns about the IPCC process.

“Judith was a one-time supporter of the IPCC until she started to find herself disagreeing with certain policies and methods of the organization. She feared the combination of groupthink and political advocacy, combined with an ingrained “noble cause syndrome,” stifled scientific debate, slowed down scientific progress, and corrupted the assessment process.”

Around the same time of these interviews, the UN InterAcademy Council (IAC) began a thorough review of the IPCC’s policies and practices, in response to issues raised by Climategate.  The IAC invited me make a presentation on my concerns. Also around the same time, the U.S. Natural Research Council Committee on Science, Engineering and Public Policy invited me to make a presentation on my concerns about the integrity of climate science in light of Climategate.

While the IPCC has instituted several of the changes recommended by the IAC, I remain very concerned about the politicization of the IPCC.  For the past 15 years, I have been an advocate for the integrity of  scientific research and assessment processes.

At this point, the IPCC WGI on the physical basis of climate change, maintains some measure of objectivity, although the Summary for Policy Makers is politicized and cherry-picks the findings.  As evidenced by the recently published IPCC Synthesis Report, it seems that science has left the room, with the emphasis on weakly justified findings on climate impacts driven by extreme emission scenarios from WGII, and politicized policy recommendations on emissions reductions from WGIII.

The “hoax” issue is even more insane.

Senator Whitehouse made the following statement: “Curry has agreed with Trump’s description of climate change as a “hoax”, writing in 2016 that the UN’s definition of manmade climate change “qualifies as a hoax.”  This is a blatant misrepresentation of what I wrote.

In a 2016 blog post titled “Trumping the climate,” I examined President-elect Trump’s statements on climate change and his frequent use of the word ‘hoax.’

<begin quote>

Let’s first look at the definition of ‘hoax’. Here are a few I spotted by googling:

• a humorous or malicious deception.
• to trick into believing or accepting as genuine something false and often preposterous
• a plan to deceive a large group of people
• a deliberately fabricated falsehood made to masquerade as truth.

With these definitions in mind, here are two examples that qualify as hoaxes that I have previously written about:

1. The UNFCCC definition of ‘climate change’ arguably qualifies as a hoax: climate change is a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.[link]. This perversion of the definition of ‘climate change’ was designed to mislead people into thinking that all climate change is caused by humans.

<end quote>

With regard to #1, here is my concern.  The UNFCCC has redefined the term “climate change” away from the traditional definition used in the geological, atmospheric, and oceanic sciences, to make a distinction between climate change—attributable to human activities altering the atmospheric composition (mainly CO2), and climate variability—attributable to natural causes. This redefinition of “climate change” to refer only to human-caused changes to the atmospheric composition has effectively eliminated natural climate change from the public discussion—the common parlance refers to “climate change,” with no mention of natural climate variability. As a result, any change that is observed over the past century is now implicitly assumed to be caused by human emissions to the atmosphere. This assumption leads to connecting every unusual weather or climate event to human-caused climate change from fossil fuel emissions.  This redefinition of “climate change” by the UNFCCC is a deception and misleading, which has arguably contributed to Trump calling climate change a hoax.

Why anyone thinks this is worth discussing in a Congressional Hearing is beyond me.

EXXON and the American Petroleum Institute

I was shown an indecipherable diagram that was created by EXXON at some unspecified date, but presumably in the 1960s or 1970s.  SW characterized this graph of CO2 concentrations and temperatures as being a ‘model’ that turned out to be pretty accurate.  Two lines both having the same trend do not constitute a model, or imply anything about causation.

I was also read a statement that was made in 1968 by a report commissioned by the American Petroleum Institute, warning that continued increases in CO2 could cause harm from warming the climate by 2000.

The point is this.  Our knowledge of climate change was in its infancy in the 1960s.  What Exxon or anyone else ‘knew’ at this time was associated with a very weak knowledge base, and is irrelevant to the current scientific debate on the issue.  We have understood the basic mechanism of the atmospheric greenhouse effect since the 19th century; the key questions remain as to its magnitude and its importance relative to natural climate variability.

The IPCC’s First Assessment Report published in 1990, which reflects the best assessment of our knowledge several decades subsequent to the Exxon ‘model’ and the AIP Report included the following summary judgment:

“The size of this warming is broadly consistent with predictions of climate models, but it is also of the same magnitude as natural climate variability Thus the observed increase could be largely due to this natural variability. Alternatively this variability and other human factors could have offset a still larger human-induced greenhouse warming. The unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more.”

My 2007 Washington Post op-ed [link]

Senator Whitehouse asked me if I stood by my 2007 op-ed, after reading aloud the part about risk and risk management. This is actually something of relevance for this Hearing.

“But if the risk is great, then it may be worth acting against even if its probability is small. Think of risk as the product of consequences and likelihood: what can happen and the odds of it happening [JC addendum:  also need to add strength of the knowledge base in assessing risk]. A 10-degree rise in global temperatures by 2100 is not likely; the panel gives it a 3 percent probability. Such low-probability, high-impact risks are routinely factored into any analysis and management strategy, whether on Wall Street or at the Pentagon.

The rationale for reducing emissions of carbon dioxide is to reduce the risk of the possibility of catastrophic outcomes. Making the transition to cleaner fuels has the added benefit of reducing the impact on public health and ecosystems and improving energy security — providing benefits even if the risk is eventually reduced. [JC qualification:  I stand by this statement, but it is most definitely not an endorsement of rapidly transitioning to wind and solar power].

There is no easy solution to this problem; the challenge is how best to develop options that are feasible, efficient, viable, and scalable. Lomborg is correct to be concerned about the possibility of bad policy choices. But I have yet to see any option that is worse than ignoring the risk of global warming and doing nothing.”

I was wrong about trusting the IPCC on polar bears, and I was wrong in most of my criticisms of Lomborg. However, my statements about risk hold up fairly well after 16 years.  I would add the following nuance from my more recent perspective of having written a book on this topic: “Climate Uncertainty and Risk,” specifically with regards to “doing nothing:”

Acceptable risk requires no management. Risks are tolerable if activities are considered as worth pursuing for the associated benefits. For tolerable risks, efforts for risk reduction or coping are welcomed, provided that the benefits of the activities are not lost. Burning fossil fuels has historically been considered a tolerable risk. Climate change risks have been characterized as acceptable, tolerable, and intolerable by different individuals and constituencies – clearly an ambiguous situation. As described in my written statement, judgments of intolerable risks from climate change relate to mistakenly conflating the slow creep of global warming (an emerging risk) with consequences from extreme weather and climate events (emergency risks).

The slow creep of warming is best characterized as a tolerable risk.  If we can eliminate this risk by reducing fossil fuel emissions in a way that does not incur further harm, then this should be welcomed.  However, plans to rapidly dismantle our power infrastructure and replace it with unreliable wind and solar power risks producing greater harm than any conceivable impacts from climate change.  My written testimony refers to this as a “transition risk.”

Volcanoes and climate change

SW’s only mention of my written testimony is a question regarding volcanoes, in response to my statement:

“Plausible scenarios of natural climate variability in the mid-21st century (not included in the climate model simulations) point to a slowdown in the rate of global warming driven by: an expected solar minimum, the possibility of explosive volcanic eruptions, and a projected shift in multi-decadal ocean circulation patterns.”

SW asked a question about whether I expected volcanoes to save us from global warming.  My take on this is consistent with the IPCC AR6 WG1 Box 4.1:

“Typically, three in every four centuries have experienced at least one eruption stronger than –1 W m^-2 (Pinatubo or larger). The volcanic aerosol burden was 14% lower during the 20th century compared to the average of the preceding 24 centuries, whereas the 13th century was among the most volcanically active, with four eruptions exceeding that of Pinatubo-1991.”

“Due to the direct radiative effect of volcanic stratospheric aerosols, large volcanic eruptions lead to an overall decrease of GSAT [global surface air temperature], which can extend to multi-decadal or century timescales in the case of clustered volcanism.”

“Given the unpredictability of individual eruptions, volcanic forcing is prescribed as a constant background loading in CMIP6 models. This means the effects of potential large volcanic eruptions are largely absent from model projections, and few studies have addressed the potential implications on 21st-century warming. One study considered future scenarios with hypothetical volcanic eruptions consistent with levels of CE [Common Era] volcanic activity under RCP4.5 and found that climate projections could be substantially altered. Although temporary, close to pre-industrial level temperatures could be experienced globally for a few years after a 1257 Samalas-sized eruption.”

“Clustered eruptions would have substantial impact upon GSAT [global surface air temperature] evolution throughout the century, and could have far-reaching implications, as observed for past eruptions.”

JC message to Senator Whitehouse

If you are going to attempt such a takedown in the future, I suggest that you need better staffers.  The questions on “corrupt”, “hoax”, Exxon, and API were truly inane.  If you are attempting to prove something such as 2004 climate model projections matching observations, you should rely on a better source than a blog post.  In any event, all this seems to have impressed the 80 or so clueless commenters on your youtube clip.  But it won’t impress serious people.

Climate change is a serious issue.  Depending on your perspective and values, there will be much future loss and damage from either climate change itself, or from the  policies designed to prevent climate change. Conflicts surrounding climate change have been exacerbated by oversimplifying both the problem and its solutions. And from mischaracterizing the risks of climate change.

Constructively working with your Republican colleagues is essential for accomplishing anything that could help reduce our vulnerability to extreme weather events and the slow creep of warming.  A good start would be to provide some modicum of respect towards witnesses invited by Republicans and carefully consider the arguments made in their testimony.  Hearings are an opportunity for Senators to actually learn things from the expert witnesses.

This piece originally appeared at JudithCurry.com and has been republished here with permission.

Judith Curry, Ph.D. (Geophysical Sciences), is president and co-owner of Climate Forecast Applications Network (CFAN) and former Professor and Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. She is author or co-author of nearly 200 refereed journal articles on climate science.