Sunday, July 23, 2017

When statistics don't tell the story you want to tell

On Friday, climate change propagandist extraordinaire and one of the world's most dislikable and obnoxious people, Marc Morano, tweeted something on his Twitter feed that caught my eye.  Here, take a look:

Here's what it said:

Climate Change Causes Less Natural Disasters in 2017 Than 10 Years Ago: Munich Re

Now, it was necessary to connect the dots from the Climate Depot article to this:

Cost of Natural Disasters Declined in Recent Years:  Munich Re

(Not exactly the same tone, is it?  This is from the Global Warming Policy Forum, a climate-denier friendly site and group;  since they call standard climate science "alarmism", you can tell.)

Back to the article.  Here's how it starts:
Frankfurt am Main (AFP) – Natural catastrophes worldwide were less devastating in the first half of 2017 than the average over the past 10 years, reinsurer Munich Re said Tuesday, while highlighting the role of climate change in severe US storms.
Interesting how the Climate Depot headline says that climate change is causing less natural disasters, while the actual article highlights the role of climate change in severe storms.  At which point I add, there's a statistically significant trend in increasing extreme 1-day rainfall events -- ascribed to climate change -- which can cause disasters like flash floods and landslides.

But here's what caught my suspicious eye, and this the wording of the Agence France Presse (AFP) article:
"Some 3,200 people lost their lives to disasters between January and June, the German group found — well short of the 10-year average of 47,000 for the period or the 5,100 deaths in the first half of 2016. "
WAIT A MINUTE.  (Deaths caused by disasters are always tragic, by the way.)  A year ago, in the first half of the year, 5100 people died in natural disasters.  This year, 3200.   But the 10-year average is 47,000.

At first I thought that was simply a factor of 10 mistake, an extra zero.  But after searching down to the actual article, and even the Munich Re numbers (Natural catastrophes in the first half of 2017), I realized it was a real number.

At which point I suspected that most of these tragic deaths weren't related to climate change at all.

Turns out I was only partially right about that.  Here's the breakdown.

Why is the 10-year average of fatalities due to natural disasters, January-June, equal to 47,000?

Two main reasons: the Haiti earthquake in January 2010, with over 220,000 fatalities, and  Cyclone Nargis in May 2008, with just under 140,000 fatalities. Add to that the Japanese tsunami, about 20,000, in March 2011, and

the total is about 400,000 fatalities. So, if without those three events the "baseline" average is around 7,000, which still seems high (the number of fatalities in the first half of 2016 was 5,100), then that gets to a 10-year average of 47,000 fatalities.

But wait! There's one more:

Russian heatwaves in June 2010: 55,000. So those four events push the total to 455,000. Bingo!

Here's where it gets interesting:

The point of Morano's tweet, and the GWPF post, was to use the Munich Re numbers to contend that climate change is causing less deaths and destruction over the past 10 years (and not, ahem, the number of deaths from disasters 10 years ago!!) But there's a lot wrong with that effort.

A. The main causes of death from natural disasters didn't have a climate element at all.  The biggest one was an earthquake, as was the fourth-largest. The second one, a cyclone, was bad because of where it hit, a low-lying highly-populated river delta. It might be possible to talk about the potential increasing strength of tropical storms, hurricanes, typhoons, and cyclones with warmer sea surface temperatures, but I don't think that is fruitful right now. Neither is a discussion of how rising sea level will make storm surges worse. So, as we've always known, these types of storms happen and they can be bad.

But there's those Russian heat waves.  Heat waves are expected to get worse and more intense with climate change (i.e., global warming).  Current Extreme Weather and Climate Change  (see quote at end)

So, buried in these statistics of tragic natural disasters is a natural disaster that climate change likely made worse, and killed about 55,000 people.  That isn't exactly the story that Climate Depot and the GWPF wanted to tell, is it?

This is the story that needs to be told:
"Natural variation alone cannot explain the increase in hot weather. Only with the inclusion of human influences can computer models of the climate reproduce the observed changes in frost days, growing season length, the number of warm nights in a year, warming on the warmest night of the year, warming on the coldest nights and days of the year, warming on the hottest day of the year, unusually hot days throughout the year, and heat waves. The increase in hot weather is a direct result of climate change, and human influence is estimated to have more than doubled the likelihood of the warming trends experienced recently in virtually every region of the globe."

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