I heard that denier meme a while back.
Please. Let's drop the hyper-vigilant boundary policing act, OK?
To be sure, it was a little zealous, apologies.
What I said is true. If you doubt it, we can look at 2012 or 2011 or 2010 or 2009 or other years, and I guarantee you that I can give you a list of places and months when there was crazy, extreme weather. Heat waves in Russia. Floods in Queensland. Drought in Texas.
So how do we know whether 2013's weather was more "incredibly unusual" than usual, or just run-of-the-mill "incredibly unusual"?
The best that we can do (that I am aware of) is statistical attribution, to say that climate change made the event x times more likely. I imagine it will take at least some time for those studies to be done for 2013, but here are a few examples for previous events:
http://www.telegraph.co.uk/earth/earthnews/8328705/Floods-caused-by-climate-change.htmlhttp://www.wired.com/wiredscience/2011/10/russian-heat-climate-change/http://onlinelibrary.wiley.com/doi/10.1029/2011GL050422/abstracthttp://www.nature.com/news/2004/041129/full/news041129-6.htmlI've found others in the past where the probability that the event was effectively "caused" by climate change is far higher than just a few times - but I can't remember which events they were offhand.
For me, there is a simple bottom line - there is a growing body of evidence that some types of extreme weather are increasing and the science of event attribution is progressing towards starting to give a feel for the role climate change might have played in a specific event. Given that we are also gaining understanding of mechanisms at work that directly influence extreme weather (such as the changing behaviour of the jet stream as per Francis et al 2012), it seems valid to me to perceive a significant climate change role in ongoing extreme weather - and to expect that the occurrence of extreme weather will not subside back to statistical norms, and if anything is likely to continue to increase (potentially with increasing rapidity).
Incidentally, I have seen the argument you presented used many times by deniers to push back public perception of climate change having played a role in any given extreme event. Are you aware of the research I'm citing to support my contention that it is now more than a subjective feeling that climate change is playing a significant role in increasing extreme weather?
The answer is not by kind of qualitatively looking around and saying "gosh, seems like a lot of weird weather lately." Human beings absolutely suck at making comparisons of phenomena across scales of space and time larger than their immediate day-to-day experience.
Actually, I think the skewed probabilities coming out more recently mean that is increasingly a safe assumption. It isn't technically valid (in the context of a single event, usually) and yet you'd be correct an ever greater portion of the time (and in some types of events already a substantial majority).
That is, or should be, common sense. It's somewhat laughable that your response is tag it with the dreaded label of "denier meme". More thought and less knee-jerk reactions would be good.
Well, what are your thoughts on the Hansen research - which I think makes a convincing case that climate change is statistically causing a significant percentage of extreme heat events globally now? (specifically those above 3 standard deviations of the norm)?
I appreciate one can only look at a statistical chance of a single event having happened (or been disproportionately more severe) as a result of climate change - and cannot say for a single event that climate change definitively caused it (and it didn't anyway, as climate change is a permanent ongoing signal imposed on top of the system as it was before), but once the probabilities are skewed far enough - it becomes scientifically accurate to say that most of our extreme weather recently is in fact a result of climate change (for certain types of extreme event).
If heat events above three standard deviations of the norm are now occurring 10x as often, you could event insist it was "due to climate change" with a 90% chance to be correct, is one way to look at it.
Notwithstanding that any single event in isolation
might have occurred anyway (and even this may cease to be true later as things change radically), I think there is a very convincing case most extreme weather is now caused by climate change (and that some types are empirically increasing).