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Comment by wcunning | Hacker News Reader

Even at the end of the parent article here, it says that scientists have no proof that hurricanes are hitting land more often. Other sources I've read say that they're not even more powerful or more frequent (the data is too noisy to draw a conclusion), though this one says that they are bringing greater masses of water onto land, which increases flooding. The real stat that's generally used to support worsening impacts is the cost of each storm. That's a poor statistic because it conflates the increased urbanization, general higher cost of buildings and real property and the greater number of buildings in coastal areas.

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Climate change is nothing to sneer at but it seems like it's now acceptable to make dubious claims about weather disasters and link every single one to climate change in some fashion. When really the picture is more nuanced; there's not necessarily any solid proof beyond cost of rebuilding that link recent hurricanes to climate change. Perhaps another example of primarily-political "junk" climate science is the 12-year figure. All these claims with no proof actually hurt the movement to remedy the very real, yet long-term issue facing us.

When discussing climate change with the average person, I get strong vibes of post-9/11 US, the idea that there is now a problem so incredibly urgent that any justification for extreme and illiberal policy is suddenly acceptable. Reddit now casually bandies about the idea of raiding Brazil to preserve its forest, in a rather disappointing mirror-image of early-2000s neoconservatism. In the face of fear we seem lose our values as Americans incredibly quickly.

Any extreme and illiberal policy is now acceptable - - except for just burning less fossil fuel.

I am not sure about what other weather disasters you are referring to but hurricanes in particular are closely tied to ocean temperatures. Warmer water increases both the formation rate and severity of hurricanes[1][2]. As the oceans get warmer, we should expect longer hurricane seasons more intense storms as a result.

[1]: https://spaceplace.nasa.gov/hurricanes/en/

[2]: https://en.wikipedia.org/wiki/Gulf_Stream

But the data are too noisy to draw the conclusion that we are already observing that predicted effect with certainty. It's not that that hypothesis is unreasonable, in fact my non-climatologist understanding is that it's very likely true. The question is what is the effect size for the recorded temperature increase to date, and what I've read says that it's both been up and down enough that we're not sure yet [0]. This is in contrast to the myriad news stories that state that we're losing billions of dollars per year due to global warming caused hurricanes. They do not provide nuance, but rather use terms that outright state causal links and major consequences.

Also, before you say that Reason is right wing (sorta granted, though less so these days as libertarians move out of coalition with the right), Ron Bailey is not a climate change denier. Read some of his other coverage before you slam the source.

[0] https://reason.com/2019/01/17/hurricane-losses/

I see the number of category 5 hurricanes since 2000 (that's 19 years ago) was 13. The previous 13 were since 1955 (that's 45 years before that). Is it unfounded to think there's been a statistically significant increase?

https://en.wikipedia.org/wiki/List_of_Category_5_Atlantic_hu...

Could be. Until someone does the analysis to look at variability over decades, that could be due to natural variations.

You are imagining this >3x increase "could be" natural variation... with what probability? Are you sure you're hanging on to something more like a 50% hope rather than a <5% hope here? Until someone does the analysis (which I bet they very much have, if you look for it), you find it somehow more plausible that it's natural variation, rather than the quite-obvious explanation that the rate has in fact increased?

It appears that Hurricanes are fairly clustered when broken down by decades so that the most active time period for category 5 hurricanes was the 2000's with the second most active being the 1930's followed by the 1960's. It's also difficult to determine the actual number of Cat 5 hurricanes in the past because previously they could only be measured roughly at Landfall and more modern measures can monitor any hurricane in existence meaning that there will be an increase in Cat 5's because of measurement bias. The impact of this is unfortunately, almost impossible to say with certainty. This is all covered in the first few paragraphs of the link you posted.

To claim a 3x increase would be an example of binning your data to exaggerate effect.

Wow, this is me "binning to exaggerate effect"? So much for assuming good faith. You yourself admit this is the most active period for hurricanes, and that it's merely "difficult to say with certainty" if it's statistical variation, and you completely dodged my question of how likely you reckon such a possibility actually is. Meanwhile I haven't even tried to look at different bins, I just picked 2000 randomly. If you're going to claim I'm cherrypicking the bins here, then wouldn't it make sense to show me a more reasonable bin that that would contradict mine?

Well no, what I said was, a decade ago was the most active period for Hurricanes. This current decade is less active than the previous one, or the 1930's or the 1960's. Most decades have little to no Cat 5 hurricane activity so if you take the last 2 decades and compare them to the previous 10, then Hurricane density seems 3 times higher even though it is currently lower than it was 70 or 100 years ago depending on your measurement period. If we were to bin in 20 year chunks, then it would put this bin as the most active by a small margin. The most reasonable way to organize it would probably be year by year but category 5's are a relatively rare event so you don't see much variation if you just compare individual years. Most are 0, with high points being 2 a year, and a very rare 3 in a year. The real issue is that extreme hurricanes are clustered events. There seem to be a number of years where they hit heavily, then stop for a while before starting back up and we only have about 100 years worth of records which isn't enough to make a lot of meaningful predictions for something that seems to run on a 30 to 40 year cycle.

This is without touching on the issue of measurement bias, which is extremely difficult to determine the level of.

According to this article [0], "But are fiercer hurricanes becoming more frequent? A July 18 article by the Colorado State University climatologist Philip Klotzbach and his colleagues in the Bulletin of the American Meterological Association finds that 'since 1900 neither observed CONUS [continental United States] landfalling hurricane frequency nor intensity shows significant trends.'" Sounds like it is natural variation.

[0] https://reason.com/2019/01/17/hurricane-losses/

Did we change how hurricanes are monitored over that period? I would imagine that with satellite imagery now we'll catch every storm that touches category 5, where before that we'd only know if the storm was category 5 at landfall or some other sensor intercept.

>scientists have no proof that hurricanes are hitting land more often

For the curious, data by decade is here (for the US):

https://www.nhc.noaa.gov/pastdec.shtml

This topic sometimes comes up because there are graphs that show the total number of hurricanes increasing, but the criticism is that shows bias because over time we began to observe more hurricanes that never made landfall.

[edit] and here is by-year, up to 2018.

https://www.aoml.noaa.gov/hrd/tcfaq/E23.html

By a quick check it seems these numbers do not match the landfall-by-decade counts above. But these are labeled "impacts/landfalls", so maybe there is some categorization difference? Is an "impact" different from a "landfall"?

[edit 2] here's one difference:

* - Indicates that the hurricane center did not make a U.S. landfall (or substantially weakened before making landfall), but did produce the indicated hurricane-force winds over land. In this case, central pressure is given for the time that the hurricane winds along the coast were the strongest.

In 2019 we assess the current state of the world by using data that goes until... 2004?!

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