John Raymond Christy is a climate scientist at the University of Alabama in Huntsville (UAH) whose chief interests are satellite remote sensing of global climate and global climate change. In February 2019 he was named as a member of the EPA Science Advisory Board.
Grégoire Canlorbe: You have been at pains to show that climate models are over-predicting warming by roughly a factor of two. Could you come back to this alleged falsification?
John Christy: We should be applying the scientific method to claims scientists (and others) are making about the climate. In this case I downloaded the output from 102 climate model simulations used by the IPCC and compared the tropospheric temperature since 1979 between the models and several observational datasets, including the satellite dataset we generate. The models on average were warming the atmosphere at a rate significantly greater than the observations. This is a test result from which we can say the models failed, and thus one shouldn’t depend on model output to characterize the future climate.
Grégoire Canlorbe: You are notably known for your involvement—along with Roy Spencer—in devising the first successful satellite temperature record. It turns out that beforehand you had already built your “first climate datasets” at the age of twelve, “using a mechanical pencil, graph paper, and long-division (no calculators back then.)” Could you tell us more about this life of invention?
John Christy: I was fascinated with the weather conditions around my home in the San Joaquin Valley of California (a desert basically) and the contrast with the climate of the Sierra Nevada Mountains immediately to the East. I was curious as to why some years were wet, others dry… why the Sierras had more precipitation and why the snow levels varied so much. I was the first high school student in California to write a simple program to predict the weather and to calculate the snow level in the mountains. These were very crude, statistical models in 1968, written for computers that were far less sophisticated than today’s cell phone. But, they introduced me to computer coding and to the power that was required to study. That was over 50 years ago.