Bjørn Lomborg writes on his Facebook page
It is phenomenal. Climate campaigners like [John] Vidal in Guardian keeps arguing that the terrible typhoon Haiyan shows we need to do more about global warming.
Yet, even *after* Haiyan, the Accumulated Cyclone Energy of all cyclones in the Western North Pacific is below normal (99%, http://models.weatherbell.com/tropical.php). The global ACE is at 74%.
As you can see in the graph below (updated Nov 10), both Northern Hemisphere ACE and global ACE are at the lowest since the 1970s.
Graph of ACE: http://models.weatherbell.com/tropical.php
Yes, there are ferocious cyclones in the world, as they always have been. But first, you can’t argue that global warming is making them worse, when the indicators are *lower*. Second, claiming that CO₂ cuts is the way to tackle cyclone damages is simply immoral. Even if we cut emissions dramatically, it will have only little impact in 50-100 years. If you want to help places like Tacloban and the Philippines, it is all about adaptation.
Again, it is likely that global warming will make cyclones somewhat stronger, though likely also somewhat fewer. In total, cyclones cost 0.04% of global GDP now. Since a richer world will also be a world with better protection (Florida is much less vulnerable to cyclones than Guatemala), by the end of the century, cyclones will cost 0.01% of global GDP. And because of increasing damages from global warming, the total cost will probably go to 0.02% of global GDP. http://www.nature.com/nclimate/journal/v2/n3/full/nclimate1357.html
But overall cyclones will destroy *less*. We will see a reduction from 0.04% to 0.02% of GDP.
And finally, remember, that we cannot see the global warming fingerprint in cyclones today or anytime soon. GFDL from NOAA estimate that an “increase may not be detectable until the latter half of the century” http://www.gfdl.noaa.gov/global-warming-and-hurricanes)
Vidal in Guardian: http://www.theguardian.com/commentisfree/2013/nov/08/typhoon-haiyan-rich-ignore-climate-change