As our oceans warm up, precipitation and hurricane intensity will increase. But more water and wind are not the reason why today's storms are destroying more communities in their wake: it's just that more and more communities are moving in that direction.
From 1970 to 2016, the number of Americans living in states directly exposed to tropical cyclones increased by 60 million. Most of this growth has occurred in coastal counties, although many people living inland still can see the impacts of persistent storms. Along with the growth of the coastal population, the number of houses has increased. The Atlantic and Gulf Coast regions, the two most exposed to hurricanes, have 34 million more homes in the current decade than in 1940.
This shift to vulnerable areas, and not an increase in the severity of storms, is what climatologists believe to be causing the rapid increase in apparent destructive power. A new analysis supporting this conclusion appeared in Sustainability of nature This week, it was conducted by a group of researchers from the National Oceanic and Atmospheric Administration and several other leading climate research centers. Their work is not new, however, it is an update of the data that these scientists have been working on for decades. We do not hear much about it, because the most common way of hearing about the destructiveness of hurricanes is simply the cost of each storm corrected for inflation. Here's what it looks like:
From this chart, you conclude that hurricanes cause far more damage than today. And it's true. But it misses a crucial point.
"In the aftermath of a natural disaster, people are quick to blame nature:" The hurricane has caused billions of dollars in damage. "However, it is common for" natural "catastrophes to be the consequence of human failures." Roger Pielke Jr., an environmental scientist at the University of Colorado at Boulder, presented it at a workshop on the social and economic impacts of weather conditions. He is also co-author of this recent paper, just as he had already been estimated on the destruction caused by natural disasters. His research has shown that it is hurricane exposure and not the intensity or frequency of the storms themselves that has dramatically increased the damage in recent years.
To understand this, he and other researchers use a measure called standardized losses. Rather than considering only inflation, this method also takes into account societal changes such as the increase in the number of dwellings or the population over time. Standardized losses therefore allow you to directly compare the damage done by a storm in the years 1910 and 2010. When Pielke and his colleagues discuss it, it looks very different from the inflation only data:
These figures show no overall trend towards more destruction when the influence of a changing society is removed.
Does this mean that hurricanes do not get worse? It may sound a bit confusing, but no.
In its overview of global warming and hurricanes, NOAA notes that "it is likely that warmer greenhouse gases will heighten the intensity of hurricanes in the next century to come. global level and will result in higher precipitation rates than current hurricanes ", but also not necessarily been proven yet. Storm surges are also likely to get worse as sea level rises, but again, these increases have not been as significant. Similarly, we found a very small increase in the number of high-grade storms, but the NOAA summary indicates that the increase in the Atlantic basin is unlikely to be statistically significant. Projections suggest that this may become important, but no significant effects should occur before the second half of this century.
The apparent overall increase in the number of hurricanes is probably due to changes in the way we detect them. At the beginning of the 20th century, the only hurricanes recorded were those encountered by humans – those who hit land or struck a ship. Today, we have satellites that capture every storm, no matter where it is. When researchers adapt to this change of observation, it becomes clear that the number of hurricanes has not changed and that we may have fewer storms.
None of this means that global warming has no impact on hurricanes. These storms are likely to become worse with increasing ocean surface temperature and rising sea levels. so much worse they cause a lot more damage to the coastal US. We can not blame nature for that: it all depends on where we build.