Thursday, April 28, 2016

On Baseball and Climate Change

So last week Bill Nye (the "Science Guy") tweeted an insinuation that climate change may be responsible for the Houston floods that cost the lives of seven people and five billion in damages. Here's the exact tweet:

This isn't the first time Mr. Nye has issued similar tweets after various weather events. For example, here's a tweet when Tropical Storm Bill was approaching Texas while Alaska was receiving above normal temperatures:

Last year, Nye lashed out at meteorologists for failing to link the 2015 Texas floods and Oklahoma tornadoes to climate change:

Combining these events with other notable recent weather events ... Hurricane Sandy (largest Atlantic storm measured by diameter), Hurricane Patricia (strongest 1-minute sustained winds on record) and the significant flooding in Myrtle Beach partly caused by Hurricane Joaquin ... and it certainly gives pause to consider the possibility of whether Bill Nye is correct, that these events are linked to climate change.

However, with all due respect to the Science Guy, his tweets are way off base and here's why. Even in an unchanging climate, new weather records and unusual weather events are guaranteed to occur on a regular basis. It's a mathematical inevitability. To see that in a simple way an analogy is presented from major league baseball, where baseball records are broken all the time without any changes to the sport. For example, below is a list of some of the new records that were made or broken in the 2015 playoffs:

  • First time a lead off batter hits inside-the-park home run to start a world series.
  • Longest game 1 in history of world series. 
  • NY Mets Daniel Murphy became the first player to hit a home run in six consecutive playoff games.
  • Chicago Cubs set a record for most home runs hit by a team in a single playoff game (6).
  • Wrigley Field in Chicago got its first playoff series win since opening 100 years ago.
  • Most post-season home runs on a single day (21).
  • Most post-season total runs on a single day (61).
  • Kyle Schwarber set a record for the most post-season home runs before turning 23 years of age.
  • Alcides Escobar sets the longest hitting streak in a single post-season (15 games).
  • Royals set single postseason record for the  most comeback wins after trailing by multiple runs (7).
  • Royals were the first team to score 5 runs in an extra inning of a world series game.
  • Royals only team in history to win 3 world series games after trailing the 8th inning or later.
  • Royals most runs scored in the 7th inning or later in a single postseason (51).
Now, did major league baseball change during 2015? Of course not, same rules and same baseball fields. Yet despite the lack of significant changes to the sport new records are made in baseball every year, and it doesn't require a change in the nature of baseball to do so. As mentioned above it's a statistical inevitability. As the sample size increases chances are something extreme will happen.

Here's another way to look at it, this time using analogies from other areas. For example, the more days you spend driving in a car the more likely over time it becomes that at some point you'll get in a car accident. The more rounds of golf you play the more likely it is that some day you'll make a hole-in-one. The more times you spend outside in a thunderstorm the more likely it becomes that one day you'll eventually get struck by lightning. The more days you invest in the stock market the more likely it will become that your money will be subject to a market crash.

Similarly, with thousands of cities around the world, chances are weather records are going to be broken somewhere on the planet in a given day/week/month and it doesn't mean that the climate is changing. That is the point I hope to drive home with this post, and the point that is lost by many who talk about climate change. New records and strong storms do not by themselves equate to climate change. To assess whether the climate is changing the long term frequency trends must be plotted.

For example, here is a plot of violent tornadoes vs. year. Note that there is no increase in the number of tornadoes over time.

Here's one for global tropical storms and hurricanes. Again note that there is no trend in these storms over time.

Here's one for extreme precipitation:

So, as much as Bill Nye wants to preach climate change is responsible for all the recent storms, unfortunately there is no signal in the data to support his tweets.

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