Saturday, July 27, 2019

Another grossly incompetent lying chart by climate deniers

Climate deniers are a reliable source of grossly incompetent lying charts. Just remember this one, which you'll see in How Charts Lie. Nigel Hawtin has just sent me a link to the gem below by The Global Warming Policy Forum, a British organization that says that the scientific consensus is climate “alarmism”, and then engages in some actual alarmism by warning us about something called “climate communism”.

The GWPF director is Benny Peiser, whose academic specialty is analyzing sports and physical activity. That means that he is as qualified as I am to discuss climate science with rigor (disclosure: neither of us is qualified at all.) However, and unfortunately for the GWPF, I can discuss charts, and the one above is a blatant example of cherry-picking by conveniently cropping the X-axis to select the time frame that “proves” what you want to believe.

It's perhaps not a coincidence that the GWPF chose 2014 as the starting point for the chart; 2014-2016 were El NiƱo years, and these tend to be warmer. Moreover, you can see the temperature slightly picking up by the beginning of 2019. NASA has a comprehensive article about why the Earth isn't really cooling, and it discusses the GWPF chart.

Anyway, if we want to discuss temperature variation and anthropogenic impact on it we need to go back in time to display long-term trends. Here's an example from the same thread.

Chart by Datagraver

(Another trick liars use—but not in this case, this is a warning about other charts—is to select their data carefully before making any graphic. Climate deniers don't just crop chart axes, but also favor nominal temperatures, often from specific regions. Real scientists recommend to show temperature anomalies instead. Anomalies are differences from a baseline temperature that is often the average of decades of data. This is a good explanation of how anomalies work and why they are a better choice if the goal is to have an informed conversation, not to lie.)