To identify the cause of global warming, Doctor Anthony Broccoli of Rutgers University looks at the evidence just as Sherlock Holmes would. A review of physics leads to the primary suspect: heat-trapping greenhouse gases such as carbon dioxide.

Statue of Sherlock Holmes

Broccoli: “The earth’s temperature is maintained by a balance between the energy coming in from the sun and the energy that the earth radiates back to space in the form of infrared energy. Greenhouse gases make it harder for that infrared energy to escape to space.”

So Broccoli deduces that the greenhouse gases humans emit into the atmosphere will trap additional heat and warm the earth. Observations support the theory.

Broccoli: “We see warming in many forms in weather stations on land, warming ocean temperatures, glaciers retreating, and less ice on rivers and lakes.”

To determine if this warming can be explained by natural causes alone, Broccoli turns to computer models of the climate. They show that without human caused emissions, the earth’s climate would not have rapidly heated up, as it has over the last few decades.

So when you consider the evidence, it’s elementary, dear Watson . . . Recent global warming is primarily human-caused.

Reporting credit: ChavoBart Digital Media.
Photo: Statue of Sherlock Holmes in London (copyright protected).

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Bud Ward

Bud Ward was editor of Yale Climate Connections from 2007-2022. He started his environmental journalism career in 1974. He later served as assistant director of the U.S. Congress's National Commission...