Links tagged “floods”

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 Two: All event attribution studies should be preregistered, which means “committing to analytic steps without advance knowledge of the research outcomes.” All methodological choices should be made transparent in advance of any event attribution study and submitted to an independent registry...

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.

During the last 30 years the mortality risk from climate-related disasters plunged more than six-fold and the economic loss rates went down five-fold...

A paper published in the scientific literature in July 2019 had the refreshingly plain-language title “Empirical evidence of declining global vulnerability to climate-related hazards”. Care to guess what it’s about? In slightly less plain-language, the authors say:

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.

That is not simply my conclusion, but the consensus view of the Intergovernmental Panel on Climate Change, the U.S. National Climate Assessment, and the World Meteorological Organization.