On Climate Denialism - Deny Deny Deny!

I don’t hope to cover the nature of climate denialism in its entirety in one single argument, but rather intend to provide rough categories of the types of denialism and motivations of denialists.

I’ll start with the categories of denialism because they seem to be easier and, to a certain extent, more clear-cut.

The most hard-core type of denialist simply denies that climate change is happening.  Examples of this are those who make claims that:

global warming may well have been happening a bit, but it has now plateaued,

glaciers are growing and sea ice isn’t melting,

sea levels aren’t rising,

we are just experiencing a blip and temperatures will soon return to normal or plummet into an ice age,

historical records have been tampered with to give only the appearance of global warming, and

hot temperatures were experienced in the past (so why are we making a fuss now?)

That first is one that gets renewed every few years, whenever the records can be twisted into supporting the claim, usually based on a longer period where the first year is abnormally warm and the final year is unusually cool such as 1983-1996, 1998-2012, 1990-2000, 2003-2013 and 2016-2019 (but 2016-2018 was particularly exciting for this crowd, with a short term drop of more than 0.5C per year).  But when you look at the entire period in context, it becomes significantly less compelling (“Extra! Extra! Read all about it!  2018 is the Coldest Year since 2014 (which was the warmest year on record up until that point)!”):

It’s true that a glacier is growing, but again, this is a fact taken out of context.  One glacier is growing in Greenland but the entirety of the ice sheet is still diminishing.

I addressed sea ice in the Ice Extent Challenge and sea levels in both Sea Levels Rising and Sea Level Denialism.

There are quite a few climate deniers in the “it’s all due to the sun and it’ll start cooling soon” camp.  One of these is David Evans, husband to Joanne Nova, who is a proponent of the notch-delay solar theory and has made a bet with Brian Schmidt that global warming will not be as significant as was being projected (it’s quite a complicated bet, so it’s better that you read the details at the source).  The first phase of that bet came due this year, for Brian to win $1500, the climate needed to have warmed by 0.17C over the decade.  It warmed by 0.29C over the period by my calculations.  I’ve not yet seen any response from Evans or Nova, but Schmidt is willing to donate his winnings to support recovery from the bushfires being experienced in Australia.

The crowd who are convinced that we are just about to enter into a cooling period, if not a full-blown ice age, are quite resilient.  Each time there is two or three years cooling from a high point, they come out of the woodwork to proclaim a different type of doom.  What also brings them out is any major snow or polar vortex event, as if a local weather event were evidence of global cooling.  Their simplistic argument is “if the world is cooling, why is it snowing/cold where I am?”  Senator James Inhofe ran the same sort of argument when he carried a snowball into the US Senate in Washington DC in 2015 (and that was before the US had a president who had even earlier claimed [in 2012] that climate change was a hoax perpetrated by China [he has since backed up a tiny bit on the climate denial, verbally, although his actions don’t quite mesh with his words]).

Then there is the claim that there is some tampering of climate records.  This is a common refrain of Tony Heller, who is a master at cherry picking.  It is true that there are corrections made to historical temperature records.  Occasionally arcane explanations are provided as to why these corrections are made – usually due to interpolation of trends across multiple sites to eradicate erroneous readings, or to account for relocation of weather stations (which tends to happen after years of encroaching suburbia, which has an incremental impact on readings).  However, even if we were to accept all of Heller’s carefully cultivated evidence, it’s not a major issue that the historical records now tell us that the temperature has risen by 2.0C since 1884 rather than just 1.5C.  Even 1.5C in that time period is not good and the trend continues to be warming.

Sometimes, when digging through the historical records, the aim of the denialist is to find not so much evidence of record tampering, but rather evidence of either past warm periods or scientists being worried about global cooling.  There are paleoclimatologists who point out that thousands or hundreds of thousands of years ago, it was as warm as or warmer than it is today (or that CO2 was higher than today), which is true enough.  There are news reports of heatwaves way back into the early 1900s and beyond.  That in itself is not a surprise, given that a heatwave is a period abnormally warm weather (the term “heatwave” wasn’t used that much before the 1920s, but periods of abnormally warm temperature would have happened anyway).  The problem is that this definition allows for a moving feast, given that the “normal” shifts.  That said, there are high temperature records that still stand from the 1930s (Washington DC, for example).  The problem is that there’s a lot of cherry picking involved.  Warm summer temperatures are trumpeted but the very cold winters are ignored.  Additionally, a single location being very warm on a few days one year is no guarantee that the entire globe is going to be warm that year, as can be seen in the graph at the top of this article.  1930 was a bit warmer than 1929, but it was a lot cooler overall than the early years of the 1940s (which were a bit of an anomaly in themselves).

It’s similar with worries about global cooling.  It is true that a group of scientists in the 1970s were concerned that the world was going into a cooling period, which was not totally unreasonable, given that there was a cooling trend apparent in the records since the 1940s.  However, what is ignored is that there were more scientists at the time who were effectively saying that the apparent cooling trend was masking the real trend which was for warming (Peterson 2008):

So far, I have not seen anyone who seriously claims that there has been no warming whatsoever over the 20th century and since.  Perhaps there are some out there, but I’ve not had the pleasure of deconstructing their illusions.

The bottom line is that, to be a real hard-core denialist, you need to be able to strictly filter your data.  Not many people are able to do that, but there are other options.  You could misrepresent (or misunderstand) the data.  You could minimalise the consequences of the data.  Or (and if I write an entire article on this one, it’s surely going to be quite short), you can just ignore the data, and any potential consequences.  More on these later.

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Next: “Misdirection and Misinterpreting the Climate” or “You keep using that word - I do not think it means what you think it means”