Michael Mann echoing Keven Trenberth’s position that all weather now has a climate change component since it is occurring in an altered atmosphere (one with more GHGs, heat and water vapour amongst many other factors).
But herein lies the crux—we no longer live in a world without warming. Given that 1985 was the last year with temperatures below the 20th century average, and 2000-2010 was the hottest decade on record, it has become impossible to say for certain that any given storm is free from the influence of our warmed world.
While contrarians may dislike it when activists or actors like George Clooney point out the linkage between climate change and extreme weather, the bottom line is this: climate change makes tropical storms more damaging. Not only through increased wind speed and rainfall, but most notably through rising sea levels. This means greater damage and loss of property and life.
I think the last paragraph is the most important and where the focus should be. One can make credible arguments and dive deep into technical arguments arguing whether or not Haiyan was caused or intensified by climate change. These arguments may be scientifically important but they send a message to the public that scientists are still debating and that therefore us lay people can’t drawn any conclusions or lessons from Haiyan. Though obviously we can. As Mann says “climate change makes tropical storms more damaging. Not only through increased wind speed and rainfall, but most notably through rising sea levels. This means greater damage and loss of property and life.“. This is true whether or nor Haiyan was caused by climate change. And this is where I think the focus should to be.