The Atlantic hurricane season has produced its first storm while a typhoon threatens Japan. This seems like a good time to talk about hurricanes, starting with this re-post from last year.
Typhoon Haiyan was one of the most powerful storms to make landfall in history. It brought moments of terrible clarity and it raised a lot of questions.
The storm’s timeline began on November 2, 2013, as a low pressure area east of Micronesia. By November 4th it had become a tropical storm and Japanese and International authorities named it Haiyan. The next day, Haiyan intensified into a typhoon—what, in the Atlantic, would be called a hurricane. By November 6th, Haiyan had sustained winds of over 150 mph and was heading towards the Philippines. That country’s authorities use a separate system for naming typhoons and designated the storm Yolanda. They posted warnings and then began evacuations
At 4:40 AM on November 8th, the storm made landfall, bringing record-breaking, 195 mph winds. That day, the typhoon cut across Leyte Island, pushing a massive storm surge up a narrow bay and into Tacloban City, essentially flattening it. Thousands of people died. In the afternoon, Haiyan/Yolanda weakened and then left the country, hitting the northwest corner of Vietnam as a tropical storm before moving into China, killing six people.
The following Monday, on November 11th, a Filipino diplomat named Naderev Sano took the floor of the UN climate talks in Warsaw, Poland. He blasted the rich countries and climate deniers of the world for allowing global climate change to cause disasters such as Haiyan/Yolanda. He later pledged to not eat until the meeting made some sort of substantive progress on climate change. No one knew how bad the damage in Layte was or how many thousands of people had died. Sano had family in Tacloban; when he made his speech, he didn’t know where all of them were.
The Philippines have always gotten a lot of typhoons, and the tropical cyclones of the Pacific are typically more serious than those of the Atlantic. Storm like Haiyan are a rare but predictable tragedy for the region. But, as global warming causes more and more extreme weather, tropical cyclones like Haiyan are likely to get more frequent. Changing weather patterns could also bring more storms to unusual areas, like Vietnam and China.
But was Typhoon Haiyan really a record-breaking example of the new, globally warmed normal? And what does it mean for us if the answer is “maybe”?
Warm water fuels tropical cyclones, so warmer water should mean more powerful storms, everything else being equal. But, everything else is not equal; there are other factors that influence tropical cyclone development, and how all these factors will interact is still not clear. So while scientists are fairly sure that global warming will lead to more intense and possibly more frequent storms, they are still arguing over the details of their predictions.
It’s not even clear whether climate change has already increased storm frequency or severity. The problem is that tropical cyclones have always varied. There have always been occasional bad storms, so one bad storm doesn’t mean anything. To spot the effects of climate change, researchers need to look at multiple storms to see if there is a trend. But human industry has been causing climate change since the Industrial Revolution, and we really only have good tropical cyclone data for a couple of decades. Storms vary a lot from year to year, and how data are collected and analyzed has also changed over the years.
While some studies conclude that tropical cyclones have definitely gotten windier due to climate change, other researchers are not so sure. The scientific consensus is still “probably.”
It’s actually debatable whether Haiyan even deserves the title of most powerful winds at landfall. The previous record is 190 mph at landfall, by Hurricane Camille, in 1969. However, various inconsistencies of data collection and analysis (including the fact that Camille destroyed all the wind gauges as it came a ashore, meaning that 190 mph is an estimate) mean that Camille could have had stronger winds and Haiyan less strong winds than each storm gets credit for.
All of this uncertainty causes a lot of confusion but, realistically, none of it really matters.
The fact is that most people who die in hurricanes don’t die of wind. They die of water, in coastal storm surges and rain-driven floods. And we know that storm surges are getting more destructive because the sea level is rising. We know, too, that storms have more rain in them now because a warmer atmosphere carries more water faster (because rain storms are bigger the droughts between storms are bigger, too). There is no scientific uncertainty about either of these factors.
So, whether hurricanes have been getting stronger or more frequent or not, and whether either trend continues or not, hurricanes either have or will cause more flooding which will kill more people. And this intensification is unambiguously part of climate change.
And of course, the ultimate killer in these big storms is poverty. Wealthy people can leave ahead of the storm and they generally do. Wealthy countries, like the United States, have the infrastructure for efficient evacuations and can rebuild again afterwards. The Philippine government did order evacuations, but a lot of people couldn’t get out or had nowhere to go. In the months following the storm, the recovery in Tacloban went smoothly, but most people were forced to rebuild using only storm debris. These repairs are going to be more vulnerable in the next storm. Something similar happened with Hurricane Katrina, of course, but while the United States as a whole is wealthy, the people most hurt by Katrina were not.
That means that hurricanes and typhoons are one more area where the weight of global warming is born disproportionately by the poor. While something can and should be done to alleviate poverty, it is unrealistic to expect economic policies and coastal zoning changes to completely eliminate the disparity between rich and poor during big storms. The bottom line is that climate change is real, it is here, and it is killing people. It just isn’t killing anybody the rich and powerful of the world know personally.
So, did Typhoon Haiyan (or Yolanda) have the highest sustained wind speed ever? Maybe. Are so-called superstorms getting more frequent and more powerful? Maybe. Is climate change going to make tropical cyclones more powerful and more frequent in the future? Maybe.
Do any of those “maybes” really matter? No.
Because while the world argues about hurricane wind speed averages and scientific uncertainty, the one thing climate scientists are not at all uncertain about—moving water—is going to keep killing more people, until we do something about it.