by C. Rotter, May 15, 2025 in WUWT
One would think that James Hansen—once lionized as the father of modern climate alarmism—might bask in the limelight after a fresh round of histrionics about Earth hurtling toward a “point of no return.” Instead, we find him on the pages of his latest blog-style polemic, “Large Cloud Feedback Confirms High Climate Sensitivity”, complaining that he’s being ostracized by the very media and institutions he helped train to bark on command every time the CO2 concentration ticks up another ppm.
“A strange phenomenon occurred… almost uniformly, these reports dismissed our conclusions as a fringe opinion… Are there important repercussions for the public… indeed, for the future of all people? The answer… is ‘yes.’”
https://www.columbia.edu/~jeh1/mailings/2025/CloudFeedback.13May2025.pdf
One might suggest that after decades of theatrics, people have simply stopped buying tickets to the same show.
But let’s not be hasty. His newest round of publications deserves scrutiny, not for its recycled gloom, but for the increasingly acrobatic logic and interpretive liberties embedded within.
The ‘Big FXcking Deal’ and the Cloud Feedback Feedback
At the heart of Hansen’s thesis is the observed decrease in Earth’s albedo—the fraction of sunlight reflected back into space. Hansen pegs this decline at 0.5% over the last two decades, translating to a 1.7 W/m² increase in absorbed solar radiation. This, he insists, proves that cloud feedback must be large and positive, confirming an equilibrium climate sensitivity of 4.5°C ± 0.5°C for doubled CO2.
“Earth’s albedo… has decreased about 0.5%… we described this change as a BFD… because it has staggering implications.”
https://www.columbia.edu/~jeh1/mailings/2025/CloudFeedback.13May2025.pdf
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