Graphics can be an extremely useful way to communicate science to the public. Simple graphs related to climate change can be used to show the increasing CO2 concentrations taken at Mauna Loa, increasing global temperatures, and how we know that it is human activity causing the warming.
But graphics can sometimes be deceiving, and professional climate deniers intentionally create deceptive graphics to mislead the public about the science of man-made climate change. For example, take one of the "most popular deceptive climate graphs" around. The following "widget" can be downloaded from one of the biggest climate denier blogs on the internet, Watts Up With That? (WUWT). The blog was founded in 2006 by a former TV weatherman with no apparent college degree and no climate research expertise. WUWT receives funding from Heartland Institute (a science denial lobbyist) and relies on posts by its founder, several non-science policy commentators, anonymous and pseudonymous bloggers, and the occasional contrarian climate scientist.
At first glance the widget above looks useful. It shows temperature, CO2 trend and concentration, and for some unexplained reason, a picture of the sun showing current sunspot activity.
But the graphic is incredibly deceptive. In fact, its goal is to misinform the unsuspecting public.
This intentional deception by the creators of the WUWT widget was recently examined by a science-based blog called Real Climate (RC). The site was created ten years ago by a group of respected climate scientists as a means to help explain the science to technically oriented readers. All of its current contributors are real climate scientists, each with hundreds of peer-reviewed climate publications to their credit.
Real Climate has annotated the WUWT graphic below to document four separate ploys used to deceive the public.
As can be seen, WUWT intentionally chose the data plotted to increase the "noise" (i.e., make it harder to understand), cherry picked a data set to create greater variability, manipulated the scales used to falsely suggest lack of corellation, and added extraneous information to "lead on" viewers to a false conclusion. See the Real Climate site for a more detailed discussion.
These intentional deceptions are obvious to actual climate scientists, so why do climate denier organizations do something that is easy to expose? The answer is because the goal of professional deniers' posts isn't to debate the science but to manipulate public opinion. WUWT and other denial sites target the generally ideologically-driven amateur deniers who are often willfully ignorant of the science. Professional deniers know that whatever they say (no matter the lack of qualifications of who is saying it) and whatever they provide as graphics (even obviously deceptive ones) will be accepted uncritically and unskeptically by amateur deniers, who then will saturate the internet, Facebook, and comment threads all over the blogosphere.
Finally, note that in my initial paragraph I linked to three science sites - NOAA, NASA, and the IPCC. It's always preferable to get data and explanations from the web pages and reports of the scientific organizations (or directly from the peer-reviewed papers if you have access and can weed through the highly technical scientific terminology). That said, in this age of blogs there are several that offer some accurate and useful explanations in more human language (e.g., Real Climate). Unfortunately, with the good also comes the bad, and there are plenty of denialist blogs out there that either intentionally misrepresent the science (e.g., WUWT) or push along the latest conspiracy claims.
To help people sort out which is which, I'll do a future post in this Exposing Climate Denialism series on Blogs - The Good, the Bad, and the Ugly.