This is the fifth in a series by Cornwall Alliance Senior Fellow Roy W. Spencer, Ph.D. (Meteorology), Principal Research Scientist, University of Alabama at Huntsville, exposing media bias in reporting about climate change. This first appeared as part of a longer article by Dr. Spencer on his blog.

This is one of my favorites.

As part of Al Gore’s Climate Reality Project, Bill Nye produced a Climate 101 video of an experiment where two glass jars with thermometers in them were illuminated by lamps. One jar had air in it, the other had pure CO2. The video allegedly shows the jar with CO2 in it experiencing a larger temperature rise than the jar with just air in it.

Of course, this was meant to demonstrate how easy it is to show more CO2 causes warming. I’m sure it has inspired many school science experiments. The video has had over 500,000 views.

The problem is that this experiment cannot show such an effect. Any expert in atmospheric radiative transfer can tell you this. The jars are totally opaque to infrared radiation anyway, the amount of CO2 involved is far too small, the thermometers were cheap and inaccurate, the lamps cannot be exactly identical, the jars are not identical, and the “cold” of outer space was not included the experiment. TV meteorologist Anthony Watts demonstrated that Bill Nye had to fake the results through post-production video editing.

The warming effect of increasing atmospheric CO2 is surprisingly difficult to demonstrate. The demonstration is largely a theoretical exercise involving radiative absorption calculations and a radiative transfer model. I believe the effect exists; I’m just saying that there is no easy way to demonstrate it.

The trouble is that this fraudulent video still exists, and many thousands of people are being misled into believing that the experiment is evidence of how obvious it is that CO2 emissions are driving dangerous warming.

Photo by Ed Shipul/Flickr CC.