Anthony Watts: Twitter Hits No Substitute for Science in Understanding Climate

The headline of a recent story on CNBC claimed, “Scientists Are Using Twitter to Measure the Impact of Climate Change.” I did a double-take and checked the calendar to make sure this was not April Fools’ Day, thinking this had to be some sort of a joke.

Sadly, it was not.

Incredibly, scientists are basing claims of a climate crisis on the number of people tweeting about climate events—a very bad sign for science, indeed.

The CNBC story cited a study recently published in Nature Communications, “Using Remarkability to Define Coastal Flooding Thresholds”—‘remarkability’ being a fancy, sciencey-sounding name for Twitter volume. In this study, a pair of scientists from the University of California at Davis and the Max Plank Institute for Human Development in Germany examined Twitter messages to measure how often people complained about flooding nuisances—typically caused by backed-up stormwater drains—along coastal counties, including places such as Boston, Miami, and New York.

“Coastal floods and inundation are projected to produce some of the primary social impacts of climate change, imposing significant costs on communities around the world,” the study claims. “Flooding due to high tides, storm surges, or a combination of the two is increasingly common in many coastal areas and is projected to become more frequent and severe as sea-levels rise globally.”

However, the study ignored hard, objective data such as rainfall rates, choosing instead to build a scientific case for worsening coastal flooding by noting people are tweeting about it more often. The researchers defined a “remarkable threshold” for coastal flooding when the number of Twitter posts in a particular county complaining about flooding rose by 25 percent. They then compared the Twitter data with official flood records.

The kinds of Tweets that would qualify as scientific evidence of increasing, climate-driven flooding would include, “Hey neighbors! The street is flooded again because the city didn’t clear the storm drain of junk and leaves. Don’t park out front.”

The study reveals trends of social media commentary, but certainly not objective, factual data about climate or unusual instances of flooding related to climate. It also reflects trends of social media volume in general, as well as the influence of climate propaganda coming from media sources. None of these are scientific evidence of climate change or its effects.

Here is another interesting tidbit: For some strange reason, the researchers limited the scope of their study to a relatively short period: March 2014 to November 2016. I’m always suspicious of any scientific study that doesn’t use the entire available dataset. Why not from 2014 to 2018? In many cases, analysts limit their choice of data because when they analyze data for a study and the full dataset does not provide the answer they were hoping to find, they report misleading results from a partial dataset instead.

To their credit, the researchers note Twitter data might be misleading. They mention research has demonstrated the more people experience things, the less remarkable they become. In other words, when storms and floods occur less often, they are more likely to be exciting and deserving of a Twitter post when they finally do occur.

Here is the biggest flaw in the study: nowhere in the study did the authors look at the increase of Twitter users or tweets during the same period. That’s a shocking oversight on their part. According to data for the United States compiled by Statista, Twitter’s audience grew massively from the first quarter of 2014 to the fourth quarter of 2016, from 57 million to 67 million monthly active users. This 17.5 percent increase in the number of Twitter users overlapped the period studied in the previously mentioned, dubious flooding study.

Gosh, do you think there might have been an increase in tweets about street flooding because more people were using Twitter during the months at the end of the study period than were using Twitter at the beginning of the study period?

I weep for science, and I especially weep for climate science.

  Meteorologist Anthony Watts, a senior fellow at The Heartland Institute, operates the world’s most-viewed climate website - WattsUpWithThat.com.