Skepticism and denial are two words that many climate change activists throw around. What is the difference between them? What is the appropriate usage for each? And which camp do most of so-called “global warming skeptics” fall into?

A skeptic is someone in doubt. The key word here is “doubt”. They are willing to listen to evidence from all sides because they haven’t formed an opinion yet. However, it will take very strong evidence for them to accept a theory or belief.

All scientists are taught to be skeptical – to never make assumptions, jump to conclusions, or accept a theory without asking further questions. Skepticism is scientific nature. It is a way of saying, “I don’t know enough about the topic to make a decision.” Skepticism shows inherent objectivity.

A denialist will adamantly reject something, no matter how much evidence supports it. They will only listen to evidence from the side of the debate they support. Unlike a skeptic, who will accept a theory when strong evidence arises, a denialist will never accept a theory. Denial shows inherent bias.

Applying these definitions

In the context of climate change, I feel that denial, in a way, is opposite to skepticism. All over the Internet there are people claiming that climate change is nonexistent/natural/a global conspiracy. They say that they are “skeptical” of the evidence that humans are causing the Earth to warm. Let’s look at a rather tragic story and see if it sheds some light on whether they are actually skeptical, or if they are, in fact, in denial.

In The Great Global Warming Swindle – as well as countless other sources – a graph is presented which shows the Medeival Warm Period to be slightly warmer than the present day.

This graph is from the first IPCC report, dated 1990. The film is adamant that this graph is correct. However, in the years following 1990, the IPCC did more research on the Medeival Warm Period, as almost all of their historical temperature data was from Europe. They looked at data from other parts of the world and discovered that the warming was confined to Europe. The Earth, as a whole, hardly warmed at all. By the third IPCC report, the graph had advanced dramatically, to what is known as “the hockey stick”.

This graph prompted a lot of yelling and screaming, and a lot of claims that the IPCC was forging data. But, in actuality, their data set had just improved. And it was continuing to improve. By its fourth report, the IPCC had not just a hockey stick, but a whole hockey team.

This graph, the most recent, was created by the same source as the first graph, which showed the Medeival Warming Period to be warmer than today. It was 17 years more recent. It had advanced dramatically. However, the Great Global Warming Swindle et al continued to use the graph from 1990 and claim that it was credible. Do they hold valid scientific concerns regarding the stastical methods used to create the more recent graphs? Or are they simply cherry-picking data?

There are other, similar, stories. Many skeptics put incredible faith on the idea that other planets might be warming – a dubious area of research we’re just starting to explore – and then turn around and say that the Earth’s temperature record, which has been going strong for a century, is flawed. They say that the 1970s theory of an impending ice age – which was mentioned by a single, discredited paper – held complete consensus in the scientific community, whereas there is apparently “no agreement” over the idea of human-caused warming.

They call themselves “skeptics”. But how can they really be of skeptical nature when they are clinging to certain pieces of evidence in a way that’s not skeptical at all? How can they claim that they hold logic, rationality, and common sense when they are advocating – without analysis, investigation, or statements of uncertainty – for all evidence which supports their pre-conceived conclusion?

Does this show inherent objectivity – skepticism?

Or does it show inherent bias – denial?