Abstract
Climate sensitivity is defi ned as the change in global mean equilibrium temperature
after a doubling of atmospheric CO2 concentration and provides a simple measure of global
warming. An early estimate of climate sensitivity, 1.5–4.5°C, has changed little subsequently,
including the latest assessment by the Intergovernmental Panel on Climate Change. The
persistence of such large uncertainties in this simple measure casts doubt on our understanding
of the mechanisms of climate change and our ability to predict the response of the climate system
to future perturbations. This has motivated continued attempts to constrain the range with
climate data, alone or in conjunction with models. The majority of studies use data from the
instrumental period (post-1850), but recent work has made use of information about the large
climate changes experienced in the geological past. In this review, we first outline approaches
that estimate climate sensitivity using instrumental climate observations and then summarize
attempts to use the record of climate change on geological timescales. We examine the limitations
of these studies and suggest ways in which the power of the palaeoclimate record could be better
used to reduce uncertainties in our predictions of climate sensitivity.
Translated title of the contribution | Using the past to constrain the future: how the palaeorecord can improve estimates of global warming |
---|---|
Original language | English |
Pages (from-to) | 481 - 500 |
Journal | Progress in Physical Geography |
Volume | 31(5) |
Publication status | Published - 2007 |