John Holdren in 1971: “New ice age” likely

In 1971, John Holdren edited and contributed an essay to a book entitled Global Ecology: Readings Toward a Rational Strategy for Man. He wrote (along with colleague Paul Ehrlich) the book’s sixth chapter, called “Overpopulation and the Potential for Ecocide.” (Click here to view a photograph of the table of contents, showing Holdren’s essay on pages 64-78; click on the image to the left to view the cover.) In their chapter, Holdren and Ehrlich speculate about various environmental catastrophes, and on pages 76 and 77 Holdren the climate scientist speaks about the probable likelihood of a “new ice age” caused by human activity (air pollution, dust from farming, jet exhaust, desertification, etc.).Below is a direct scan from pages 76-77 in the book Global Ecology, with an exact transcription on the right.(Following this section, scroll down to see the extended passage from which this quote was taken, with more context and more discussion.)John Holdren is now not only the “Science Czar” for the United States, but he’s also one of the original leaders of the “alarmist” wing of the Global Warming debate — and he now promotes the notion that the current climate data points to a looming planetary overheating catastrophe of unimaginable dimensions. (He helped make the charts and graphs for Al Gore’s film An Inconvenient Truth, for example.)My personal opinion is that Holdren is a “doom peddler” who latches onto the nightmare-scenario-du-jour — overpopulation, nuclear holocaust, global cooling, global warming (all of which he’s trumpeted at various points in his career) — and then wildly exaggerates it in order to scare the public into adopting his politicized “solutions.”But I’ll let you read the following quote and decide for yourself how you feel about John Holdren’s predictions. (And make sure to read the extended passage below, for more insight.)

It seems, however, that a competing effect has dominated the situation since 1940. This is the reduced transparency of the atmosphere to incoming light as a result of urban air pollution (smoke, aerosols), agricultural air pollution (dust), and volcanic ash. This screening phenomenon is said to be responsible for the present world cooling trend—a total of about .2°C in the world mean surface temperature over the past quarter century. This number seems small until it is realized that a decrease of only