Rising temperatures and the “snapshot scam”

February 29, 2012 | 1:38 pm | , Research Associate

Independent temperature records from around the world confirm that global temperatures are climbing. Ask NASA, ask NOAA, the UK’s Met Office, or the Japanese Meteorological Agency and they’ll tell you the same. Average surface temperatures around the world have increased by about 0.8°C (1.4°F) since 1880, when we began measuring. Nine of the ten warmest years on record have occurred since 2000.

Despite these facts, climate change deniers often claim that temperatures aren’t rising. We see this in a recent op-ed from the Chairman of the George C. Marshall Institute. (Yes, the same Marshall Institute that brought you denial of the dangers of smoking and the hole in the ozone layer.)

To see through the denier technique that underlies this claim, it’s important to understand the relationship between variation and trend. This animation of a man walking his dog helps to demonstrate that relationship. From minute-to-minute, the direction in which the dog’s heading varies. But by the end of the walk, a clear trend or path emerges.

© NRK. Produced by TeddyTV. Animation by Ole Christoffer Haga

Similarly, from year-to-year, annual global temperature varies. (Natural climate patterns like El Nino and La Nina contribute to this variation.) To see the overall warming trend through all the noise, you have to zoom out and look at the big picture.

It’s a textbook denier move to ignore the big picture and focus on an extremely brief “snapshot” of time instead. A graph that clearly shows the world is warming can be broken down into arbitrary chunks of time (decades, say) that show just the opposite.

This illustrated graph from Skeptical Science beautifully depicts how the “snapshot scam” works.

© 2012 cc by 3.0

In your efforts to “win the conversation” and spread the reality of the climate crisis, have you seen this tactic employed? Leave a comment and let us know.