Did global warming cause the Philippines typhoon?

When the Greens’ Adam Bandt decided to refer to the PM as ‘Typhoon Tony’ I decided to let that one go through to the keeper. But it seems that David Cameron, the UK Prime Minister, has also decided that the destructive typhoon was caused by global warming, and of course Michael Mann, he of the hockeystick, has no doubt about it all. And because news media pick up and repeat what politicians and climate scientists say, this attribution is now widespread.

But there’s not a lot in it — in fact, nothing, so far as I can see. Typhoons are mature tropical cyclones, and about a third of all of them have their genesis in the north-western Pacific, and can strike the Philippines, Japan and China. Most of them don’t reach land at all, but start and die in the wide ocean (the Pacific does, after all, take up nearly half the water surface of the globe and a third of its total surface). There are two intertwined statements being made about the most recent one, Haiyan, which devastated a city in the Philippines, with 3,200 established deaths so far. The first is that this is the worst typhoon so far (which suggests to the orthodox and their followers that since the world is warmer now than it was twenty or more years ago, warming must be responsible for the typhoon’s destructive force). The second is that we are going to see a lot more typhoons like this unless we reduce emissions.

Whether or not it was the worst depends on what you are measuring. Wind speed? Typhoon Haiyan may have been the one with the fastest speeds, but we have no way  of knowing: anenometers will be destroyed if they encounter such speeds. Haiyan was measured by satellites, but satellite measurements don’t go back past 1979. Hurricane Camille, which hit the US Gulf Coast in 1969 was thought to have had a similar speed. The Philippines weather bureau (PAGASA) says that Haiyan is the seventh strongest storm to have hit the nation.

Low pressure (the lower the pressure the more destructive the winds)? Haiyan is apparently the 58th super typhoon since 1950 to have a lower central pressure than 900 millibars, according to a website that presents a lot of data, and is not given to exaggeration. What about deaths? Wikipedia, no supporter of the sceptic approach to the AGW scare, provides a lot of detail about record typhoons. The deadliest hit China in 1975 and killed 100,000 people, mostly because the intense rain caused a dozen reservoirs to collapse. That wasn’t the wettest, however, which occurred in 2009 in Taiwan, where one county endured 2327 mm of rain in a few days (that’s not quite four year’s worth in Canberra).

Are such super typhoons becoming more frequent? That doesn’t seem to be the case either, according to the same source as that for the table above. In fact, for southern China, where there excellent records for such events, which extend back for  a thousand years, ‘the most active decades for typhoon strikes were the 1660s and 1670s’ (Wikipedia again).

 

 

In short, we have been the distressed spectators of a natural event that cost thousands of people their lives and thousands more the loss of their homes and livelihoods. It is natural to wish it otherwise, and no less natural to look for causes. There is, however, not a shred of evidence that greenhouse gas emissions from human activity had anything to do with Typhoon Haiyan, and to say confidently that they did, or allow listeners to infer such a cause, is reprehensible. Yes, climate models suggest that in a warming world typhoons will be more frequent. But the IPCC itself says that there is very little likelihood of that having occurred, and the diagram above shows why.

The Taiwan typhoon of 2009, named Morakot, did great damage in China, Japan and the Philippines as well. The deaths in 2013 seem to have been caused by inadequate infrastructure, which meant not only that the houses were insubstantial, but there were no roads that would allow the residents to get out quickly before the storm came. Others have said, and I join with them, that rapid development of countries like the Philippines would do vastly more good there than agonising about greenhouse gas emissions here.

[Footnote: I’m waiting for someone to say that the small but intense tornado that hit Hornsby this week was caused by global warming. I haven’t found a suspect yet, and I must say that the ABC in its TV news said there was no evidence that these tornadoes were becoming more frequent. Maybe someone there is reading this website! (joke)]