There seems to be an emerging public consensus that the recent global rash of extreme climatic events can be more or less directly attributed to climate change. The theory is this: climate change increases climatic variability, thus increasing the incidence of extreme weather events such as hurricanes and floods.
This is interesting, because it remains entirely uncertain whether the science actually supports this conclusion. It has become climate change denier double-speak to say that “the science is uncertain”, but I think it does more damage to the movement to allow false beliefs to propagate in the public sphere.
The belief that natural disasters can be directly linked to climate change is part emotional reaction, part logical fallacy, and this fallacy – let's call it the Edmonton winter fallacy – has already played a significant role in shaping opinions on both sides of the debate.
Humans like to make direct attributions to causes. Thus, it's much easier to believe in climate change when it's hotter than the surface of the sun outside. Al Gore exploited this natural tendency during the congressional hearing he convened on climate change way back in 1988. Picking what was historically the hottest day of the year, he went into the room the night before and opened the windows. The AC wasn't working either, and the blazing heat both inside and outside brought national attention to the issue.
Conversely, I'm convinced that it's not entirely coincidental that Canadian apathy toward climate change seems to increase during the winter. During a recent climate change march in Hamilton, our group's message was dismissed by at least one passer-by with a curt “it's -40 degrees outside”. Brushing past the slight exaggeration, it is absolutely true that the danger of “warming” does not seem so viscerally present (or even like much of a bad thing) when your toes have gone numb.
While most people can talk themselves out of such overly-simplistic cause and effect explanations, the natural disaster permutation of our Edmonton winter fallacy comes complete with what appears to be a cut-and-dried scientific explanation.
The esteemed scientific journal, Nature, certainly thinks so: a recent cover shows a flooded town, with the copy “The Human Factor” sprawled across it. This seems to have opened the proverbial floodgates, and now the mainstream media is picking up the idea that climatic disasters can be directly linked to human action, and running with it, as if they've finally been given scientific permission to state the obvious.
I'm particularly interested in this issue, because the Philippines, in addition to being at significant risk for climate-related disasters such as typhoons, is also what scientists refer to in technical terms as “really frigging hot”.
In preparation for a major pan-Asian project on climate change adaptation, I've encountered a considerable sum of literature out of the Philippines which makes the disaster-climate change connection both implicitly:
“Since 2000, nearly three million people have been affected by various disasters annually. Reming alone affected almost this number. Based on statistics provided by the NDCC, the frequency and severity of natural disasters have been increasing, as has the scale of impact (loss of life and property damage).” (Philippines UN Typhoon Appeal, 2006)
“Climate change’s impact on the Philippines is most often associated with extreme weather disturbances such as typhoons and floods, which, in turn, affect many other sectors of economic life. With 50.3 percent of its total area and 81.3 percent of the population vulnerable to natural disasters, the Philippines is considered a natural disaster hot-spot.” (Rincon & Virtucio, 2008)
It's a difficult temptation to resist. Some have amusingly attempted to incorporate such statements into their global climate change conspiracy worldview, but I think that Occam's razor probably holds here: humans are simply very good at seeing patterns and making logical leaps.
The reason why we rely on the science before jumping to the conclusion that floods are a consequence of climate change is the same reason why we don't dismiss climate science as soon as winter hits in Edmonton. How can climate science hold any credibility otherwise?
So while a direct link between natural disaster and human action will likely present itself sometime before the end of the century, it needs to be noted that direct attribution is hard to do, and very little of the rest is cut and dried. Population increases, for example, may account for the increased disaster damage in the Philippines and in Africa. If temperature increases lag roughly half a century behind CO2 concentrations, then does it not also stand to reason that extreme weather events will also be somewhat delayed? These are the main arguments being rolled out in the scientific debate over attribution.
And yet, I know I'm making my job more difficult just writing this. I'm going to have a lovely time convincing Filipinos to take immediate action on climate change after I've removed all of the immediate causes and consequences.
Climate science has already suffered too much in the name of spurring public action. But ask me again once the Filipino summer arrives, and we'll see how ready I am to blame my heat-related misery on Italian climate policy.
 As an aside: it's interesting how blogs have brought the internal debates of the scientific community into the open.