Ny studie har använt en ny metod för att studera orkaner. Genom att beräkna hur stor area som blivit totalt förstörd, kan man göra bättre jämförelser.
Climate change: Bigger hurricanes are now more damaging
The biggest and most damaging hurricanes are now three times more frequent than they were 100 years ago, say researchers.
Using a new method of calculating the destruction, the scientists say the increase in frequency is "unequivocal".
Previous attempts to isolate the impact of climate change on hurricanes have often came up with conflicting results.
But the new study says the increase in damage caused by these big cyclones is linked by global warming.
…
Previous research has concluded that the rise in damages was related to wealth, and not to any statistically significant change in frequency.
However this new paper challenges that view.
Instead of looking at economic damage, the authors looked at the amount of land that was totally destroyed by more than 240 storms between 1900 and 2018, based on insurance industry databases.
As an example, the researchers examined Hurricane Irma that hit Florida in 2017.
Around 1.1 million people were living inside the 10,000 sq km closest to the storm's landfall.
With the wealth per capita estimated to be $194,000, the scientists concluded that the overall wealth in this 10,000 sq km region was $215bn.
As the storm caused $50bn worth of damage, this was 23% of the wealth in the region. Taking 23% of the 10,000 sq km gave an area of total destruction of 2,300 sq km.
The authors found that the frequency of the most damaging hurricanes had increased by a rate of 330% per century.
And they believe that is mainly due to rising temperatures.
https://www.bbc.com/news/science-environment-50380431
Studien:
Normalized US hurricane damage estimates using area of total destruction, 1900−2018
Significance
We present an approach to normalize hurricane damage, where damage is framed in terms of an equivalent area of total destruction. This has some advantages over customary normalization schemes, and we demonstrate that our record has reduced variance and correlates marginally better with wind speeds and pressure. That is, it allows us to better address climatic trends. We find that hurricanes are indeed becoming more damaging. The frequency of the very most damaging hurricanes has increased at a rate of 330% per century.
https://www.pnas.org/content/early/2019/11/05/1912277116
Bränderna i Australien verkar vara de värsta någonsin:
Bränderna i Australien är ett ”katastrofalt hot”
Publicerad igår 12.05
De våldsamma bränder som härjar i den australiska delstaten New South Wales har redan klassats som katastrofala, men nu ser de kommande dagarna ut att bli än värre än vad man tidigare har trott.
– Vi kan inte garantera en brandbil vid varje hem, säger räddningstjänstens chef.
Lugnet före stormen. Så beskrivs det dramatiska läget i hela New South Wales, inklusive femmiljonersstaden Sydney.
Varningarna inför tisdag och onsdag i storstadsregionen låg redan på den allra högsta nivån, ”Catastrophic fire danger”, när räddningstjänsten RFS på måndagen meddelade att bränderna kan bli än värre än de trott, och täcka ett ännu större område. I stort sett hela delstatens kuststräcka på 2 100 kilometer, har nu fått den högsta varningsgraden.
https://www.svt.se/nyheter/utrikes/australien-bavar-for-nya-brander