Policy Documents

Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration

William D. Braswell –
February 28, 2008

Feedbacks are widely considered to be the largest source of uncertainty in determining the sensitivity of the climate system to increasing anthropogenic greenhouse gas concentrations, yet the ability to diagnose them from observations has remained controversial. In this paper published in 2008 in the Journal of Climate, Roy W. Spencer and William D. Braswell provide a simple model to demonstrate that any non-feedback source of top-of-atmosphere radiative flux variations can cause temperature variability, which then results in a positive bias in diagnosed feedbacks.