Rule Number One: Any model used in an event attribution study to quantify a linkage (weasel word) between climate change a specific extreme event should also produce accurate historical climate trends associated with the relevant phenomena. The claim that rainfall from Hurricane Florence was boosted 50% by climate change should have raised immediate doubts because observations have not shown an increase in rainfall related to landfalling hurricanes. Any event attribution study that cannot accurately replicate historical trends using the same model and methods is clearly fatally flawed...
Rule Number Three: All event attribution studies should integrate their findings with the traditional approach to detection and attribution of the IPCC. Event attribution studies often result is what is called “attribution without detection.”...
Individual event attribution studies are here to stay. They fill a strong demand in advocacy and in politics. Meeting such demand should be fully compatible with basic standards of scientific quality. For event attribution studies to be conducted with the highest degree of rigor they should (1) demonstrate consistency with historical observations, (2) be the product of preregistered studies, and (3) be fully integrated with the conventional methodologies of the IPCC. Until event attribution studies meet these basic rules, they will better serve purposes of advocacy rather than science.
We quantified the dynamics of socio-economic vulnerability to climate-related hazards. A decreasing trend in both human and economic vulnerability is evident. Global average mortality and loss rates have dropped by 6.5 and nearly 5 times, respectively, from 1980 to 1989 to 2007–2016. Results also show a clear negative relation between vulnerability and wealth.”
There are two main reasons for the decrease in weather-related disaster losses as a proportion of GDP.
The first reason is that many types of weather extremes associated with the greatest economic losses – including floods, drought, tornadoes and tropical cyclones (which includes landfalling U.S. hurricanes) – have not increased in frequency or intensity over the long-term.
The next figure depicts the number of strong (EF3 or greater) tornadoes observed in the U.S. each year during the same period from 1954 to 2017. Clearly, the trend is downward instead of upward; the average number of strong tornadoes annually from 1986 to 2017 was 40% less than from 1954 to 1985. Once more, global warming cannot have played a role. The most ferocious tornado outbreak ever recorded, spawning a total of 30 EF4 or EF5 tornadoes, was in 1974.