Headline #2 from New Scientist:
Abstract: The sensitivity of the climate system to an imposed radiative imbalance remains
the largest source of uncertainty in projections of future anthropogenic climate change.
Here we present further evidence that this uncertainty from an observational perspective is
largely due to the masking of the radiative feedback signal by internal radiative forcing,
probably due to natural cloud variations. That these internal radiative forcings exist and
likely corrupt feedback diagnosis is demonstrated with lag regression analysis of satellite
and coupled climate model data, interpreted with a simple forcing-feedback model. While
the satellite-based metrics for the period 2000–2010 depart substantially in the direction of
lower climate sensitivity from those similarly computed from coupled climate models, we
find that, with traditional methods, it is not possible to accurately quantify this discrepancy
in terms of the feedbacks which determine climate sensitivity. It is concluded that
atmospheric feedback diagnosis of the climate system remains an unsolved problem, due
primarily to the inability to distinguish between radiative forcing and radiative feedback in
satellite radiative budget observations.