by Judith Curry

On the politicization of ‘climate change’.

On my recent post Raw politics, I made the following remark re President Obama’s tweet:

‘Climate change is real’ is almost a tautology; climate has always changed and always will, independently of anything humans do.

Senate votes

A few hours after I posted this, the U.S. Senate provides some interesting news, summarized in this article by Andrew Freedman:

The Senate made history on Wednesday by overwhelmingly passing a non-binding “Sense of the Senate” resolution stating simply that “climate change is real and not a hoax.” Previous climate change-related non-binding resolutions were not supported by such large numbers.

In a development that seemed to surprise Democratic senators and environmental groups, the most prominent climate change contrarian in the Senate, Environment and Public Works Committee chairman James Inhofe, R-Okla., joined Democratic Sen. Sheldon Whitehouse of Rhode Island in co-sponsoring the climate amendment, which was offered during debate on a Keystone-XL Pipeline bill.

If Whitehouse’s amendment had included one additional word or phrase, such as “man-made,” it wouldn’t have drawn Inhofe’s support, or that of many of his Republican colleagues. Once he threw his weight behind it, the vote was a blowout, with senators voting 98-to-1 in favor. Sen. Roger Wicker (R-Miss.) was the sole “no” vote.

Schatz’s amendment, which he said was intended to “restate the facts” on climate change, namely that “climate change is real and humans are contributing to it,” failed by a vote of 50 to 49.

The amendment included the language that “climate change is real; and human activity significantly contributes to climate change.” The word “significantly” was cited by Senate Energy Committee Chairwoman Lisa Murkowski, R-Alaska, as a reason for a no vote.

‘Climate change’

As per twitter, many are at a loss as to how the vote could be overwhelmingly ‘yes’ on the first statement, and fail on the second statement.

It all comes down to the definition of ‘climate change’. There is both a scientific definition and a political definition.

Scientific definition. Here is what the IPCC TAR says: Refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.

Political definition. Here is how the UNFCCC defines it : climate change is a change of climate which 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.

Surprisingly, if you google ‘climate change definition’, the political definition wins out:

Oxford Dictionary: A change in global or regional climate patterns, in particular a change apparent from the mid to late 20th century onwards and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.

Roger Pielke Sr had a 2012 post entitled What does ‘climate change’ mean? Does a lack of preciseness in its definition discourage effective discussion of the risks from climate on key environmental and societal resources? RP Sr. cites some additional definitions, but I found this excerpt from RP Jr to be particularly illuminating:

As written on page 145 of Climate Fix, in relation to the United Nations Framework Convention on Climate Change” definition,

“The IPCC adopts a broader definition of “climate change” that is more scientifically accurate. Claims that climate policy should be based on the work of the IPCC typically fail to recognize that the policy community has rejected the most fundamental statement of the IPCC on the issue – the very definition of “climate change”.

So . . . President Obama and Senator Whitehouse seem to be referring to the political definition of ‘climate change’, whereas climate ‘denier’ Senator Inhofe seems to be referring to the scientific definition.

‘Significant’

While we’re talking semantics (again), the other word that caught my attention is ‘significant’, it seems that a number of ‘no’ votes hinged on this word. Let’s head to the dictionary again:

Significant: large enough to be noticed or have an effect; sufficiently great or important to be worthy of attention; fairly large in amount or quantity.

Well ‘significant’ seems to have both a scientific and a political/values connotation:

large enough to be noticed or have an effect (scientific)

sufficiently great or important to be worthy of attention (political)

Going back to the issues raised on my recent post ‘Most, more than half‘, how does ‘significantly’ relate to ‘most’ and ‘more than half’? Well in the political context, it would seem that ‘significantly’ would relate to proposed policy options to deal with the issue. If human-caused climate change was not predominant of natural causes of climate change, then reducing CO2 emissions would have little impact on the climate. On the other hand, if you are focused on regional severe weather events and adaptation measures, you might have a lower threshold ‘large enough to be noticed’ for considering policy options.

Politicians versus scientists

The bottom line is that the majority of U.S. Senators do not seem to buy the IPCC AR4/AR5 attribution statements ‘most’ and ‘more than half’, with a vote of 50 (yes) to 49 (no).

If you equate ‘significantly’ with ‘mostly’, then these results are not too different from the recent survey of professional members of the American Meteorological Society [link] that only 52% state the the warming since 1850 is mostly anthropogenic.

Disagreement

So, why the disagreement? Here are some of the scientific reasons:

Insufficient observational evidence

Disagreement about the value of different classes of evidence (e.g. models)

Disagreement about the appropriate logical framework for linking and assessing the evidence

Assessments of areas of ambiguity and ignorance

Belief polarization as a result of politicization of the science

And here are some reasons for disagreement among the Senators:

Insufficient understanding of the science and the science debate

Concerns over the politicization of the science

Distrust of climate science (e.g. Climategate, advocacy etc)

Ambiguities in the language used to communicate climate change

Clashes of values, politics, etc.

The disagreement isn’t going to go away. In fact, disagreement spurs scientific discovery and can spur development of better policy options. A way forward in the face of disagreement is suggested in a previous post World Bank: Agreeing on Robust Decisions: A Process for Decision Making Under Deep Uncertainty.

I just spotted this relevant statement in The Conversation: “foster pragmatic climate policies that do NOT hinge on scientific truth”

Here’s to hoping that the U.S. Senate can constructively use its disagreement on the issue of climate change to productively explore robust policy options.