Posts tagged ‘ACE’

Most College-Age Kids Probably Can't Remember A Major Hurricane Landfall

Most folks, even those who say they are data-driven, are not data-driven.  They react to their perception.  If some sort of activity suddenly makes the news more, we assume that activity is increasing, even if all that is happening is that the activity is simply making the news more.

A lot of the folks who want to blame this year's landfalling hurricanes on global warming are making this mistake.  If you are 20, the last major hurricane landfalls were in 2005 when you were 8.  The last decade has seen a nearly unprecedented drought in US major hurricane landfalls, so against the backdrop of this drought, several major Atlantic storms seems highly unusual.  But I grew up in the 1960's to the 1980's on the Gulf Coast and hurricanes were a regular part of our life then.  When I lived in Clear Lake City, Texas, we had so many in a few years in the 1980's that I had a special spot picked out to park my car to keep it above flood waters.  In the 1990's, we had a memorable vacation where we rented a house on the North Carolina coast for a month and got hit by three hurricanes -- we spent the whole trip hiding in the laundry room from tornado warnings and evacuating back and forth to the interior of the state.

For those who like simple charts, the WSJ had a good one the other day:

Making this a chart of hurricane landfalls deals with the public perception issue, as landfalls tend to be the only ones we really remember.  But this is actually a terrible metric (even though it makes my point about Irma and Harvey not representing any sort of upward trend) because landfalls are random and may not really represent actual hurricane activity.  A better metric is accumulated cyclonic energy of tropical storms, which looks at a sort of integral of storm strength over time.  This does not show a trend either, but since I cannot find a chart of ACE updated with recent activity I am not going to put it up here.   Here it was as of June of this year, and this chart only goes back to 1970 -- if we had good data early in the 20th century it would have been much higher.

 

 

Trend That is Not A Trend: Increase in Typhoons and Hurricanes

The science that CO2 is a greenhouse gas and causes some warming is hard to dispute.  The science that Earth is dominated by net positive feedbacks that increase modest greenhouse gas warming to catastrophic levels is very debatable.  The science that man's CO2 is already causing an increase in violent and severe weather is virtually non-existent.

Seriously, of all the different pieces of the climate debate, the one that is almost always based on pure crap are the frequent media statements linking manmade CO2 to some severe weather event.

For example, Coral Davenport in the New York Times wrote the other day:

As the torrential rains of Typhoon Hagupit flood thePhilippines, driving millions of people from their homes, the Philippine government arrived at a United Nationsclimate change summit meeting on Monday to push hard for a new international deal requiring all nations, including developing countries, to cut their use of fossil fuels.

It is a conscious pivot for the Philippines, one of Asia’s fastest-growing economies. But scientists say the nation is also among the most vulnerable to the impacts of climate change, and the Philippine government says it is suffering too many human and economic losses from the burning of fossil fuels....

A series of scientific reports have linked the burning of fossil fuels with rising sea levels and more powerful typhoons, like those that have battered the island nation.

It is telling that Ms. Davenport did not bother to link or name any of these scientific reports.  Even the IPCC, which many skeptics believe to be exaggerating manmade climate change dangers, refused in its last report to link any current severe weather events with manmade CO2.

Roger Pielke responded today with charts from two different recent studies on typhoon activity in the Phillipines.  Spot the supposed upward manmade trend.  Or not:

 

I am not a huge fan of landfalling cyclonic storm counts because whether they make landfall or not can be totally random and potentially disguise trends.  A better metric is the total energy of cyclonic storms, land-falling or not, where again there is no trend.

Via the Weather Underground, here is Accumulated Cyclonic Energy for the Western Pacific (lower numbers represent fewer cyclonic storms with less total strength):

 

And here, by the way, is the ACE for the whole globe:

 

Remember this when you see the next storm inevitably blamed on manmade global warming.  If anything, we are actually in a fairly unprecedented (in the last century and a half) hurricane drought.

Did Your SUV Cause the Haiti Earthquake?

The other day, environmental blog the Thin Green Line wrote:

At the American Geophysical Union meeting late last month, University of Miami geologist Shimon Wdowinski argued that the devastating earthquake a year ago may have been caused by a combination of deforestation and hurricanes (H/T Treehugger). Climate change is spurring more, stronger hurricanes, which are fueled by warm ocean waters....

The 2010 disaster stemmed from a vertical slippage, not the horizontal movements that most of the region's quakes entail, supporting the hypothesis that the movement was triggered by an imbalance created when eroded land mass was moved from the mountainous epicenter to the Leogane Delta.

I have heard this theory before, that landslides and other surface changes can trigger earthquakes.  Now, I am not expert on geology -- it is one of those subjects that always seems like it would be interesting to me but puts me in a coma as soon as I dive into it.   I almost failed a pass-fail geology course in college because in the mineral identification section, all I could think to say was "that's a rock."

However, I do know enough to say with some confidence that surface land changes may have triggered but did not cause the earthquake.  Earthquakes come from large releases of stored energy, often between plates and faults.  It's remotely possible land surface changes trigger some of these releases, but in general I would presume the releases would happen at some point anyway.  (Steven Goddard points out the quake was 13km below the surface, and says "It is amazing that anyone with a scientific background could attempt to blame it on surface conditions.")

The bit I wanted to tackle was the Thin Green Line's statement that "Climate change is spurring more, stronger hurricanes."   This is a fascinating statement I want to attack from several angles.

First, at one level it is a mere tautology.  If we are getting more hurricanes, then by definition the climate has changed.   This is exactly why "global warming" was rebranded into "climate change," because at some level, the climate is always changing.

Second, the statement is part of a fairly interesting debate on whether global warming in general will cause more hurricanes.  Certainly hurricanes get their power from warm water in the oceans, so it is not unreasonable to hypothesize that warmer water would lead to more, stronger hurricanes.  It turns out the question, as are most all questions in the complex climate, is more complicated than that.  It may be hurricanes are driven more by temperature gradients, rather than absolute temperatures, such that a general warming may or may not have an effect on their frequency.

Third, the statement in question, as worded, is demonstrably wrong.  If he had said "may someday spur more hurricanes," he might have been OK, but he said that climate change, and by that he means global warming, is spurring more hurricanes right now.

Here is what is actually happening (paragraph breaks added)

2010 is in the books: Global Tropical Cyclone Accumulated Cyclone Energy [ACE] remains lowest in at least three decades, and expected to decrease even further... For the calendar year 2010, a total of 46 tropical cyclones of tropical storm force developed in the Northern Hemisphere, the fewest since 1977. Of those 46, 26 attained hurricane strength (> 64 knots) and 13 became major hurricanes (> 96 knots).

Even with the expected active 2010 North Atlantic hurricane season, which accounts on average for about 1/5 of global annual hurricane output, the rest of the global tropics has been historically quiet. For the calendar-year 2010, there were 66-tropical cyclones globally, the fewest in the reliable record (since at least 1970) The Western North Pacific in 2010 had 8-Typhoons, the fewest in at least 65-years of records. Closer to the US mainland, the Eastern North Pacific off the coast of Mexico out to Hawaii uncorked a grand total of 8 tropical storms of which 3 became hurricanes, the fewest number of hurricanes since at least 1970.

Global, Northern Hemisphere, and Southern Hemisphere Tropical Cyclone Accumulated Energy (ACE) remain at decades-low levels.

The source link has more, and graphs of ACE over the last several decades (ACE is a sort of integral, combining the time-average-strength of all hurricanes during the year.  This is a better metric than mere counts and certainly better than landfall or property damage metrics).

So, normally I would argue with alarmists that correlation is not causation.   There is no point in arguing about causation, though, because the event he claims to have happened (more and stronger hurricanes) did not even happen.  The only way he could possibly argue it (though I am pretty sure he has never actually looked at the hurricane data and simply works from conventional wisdom in the global warming echo chamber) is to say that yes, 2010 was 40-year low in hurricanes, but it would have been even lower had it not been for global warming.  This is the Obama stimulus logic, and is just as unsupportable here as it was in that context.

Postscript: By the way, 2010 was probably the second warmest year in the last 30-40 years and likely one of the 5-10 warmest in the last century, so if warming was going to be a direct cause of hurricanes, it would have been in 2010.    And yes, El Ninos and La Ninas and such make it all more complicated.  Exactly.  See this post.