The body of evidence supporting human-caused global warming is vast – too vast for climate denial blogs to attack it all. Instead they focus on what a new studypublished in the journal Bioscience calls “keystone dominoes.” These are individual pieces of evidence that capture peoples’ attention, like polar bears. The authors write:
These topics are used as “proxies” for AGW [human-caused global warming] in general; in other words, they represent keystone dominoes that are strategically placed in front of many hundreds of others, each representing a separate line of evidence for AGW. By appearing to knock over the keystone domino, audiences targeted by the communication may assume all other dominoes are toppled in a form of “dismissal by association.”
Basically, if these bloggers can create the perception that the science underlying polar bear or Arctic sea ice vulnerability to climate change is incorrect, their readers will assume that all of climate science is fatally flawed. And blogs can be relatively influential – surveys have shown that blog readers trust them more than traditional news and information sources.