Constraints on radiative forcing and future climate change from observations and climate model ensembles

  title={Constraints on radiative forcing and future climate change from observations and climate model ensembles},
  author={Reto Knutti and Thomas F. Stocker and Fortunat Joos and Gian-Kasper Plattner},
The assessment of uncertainties in global warming projections is often based on expert judgement, because a number of key variables in climate change are poorly quantified. In particular, the sensitivity of climate to changing greenhouse-gas concentrations in the atmosphere and the radiative forcing effects by aerosols are not well constrained, leading to large uncertainties in global warming simulations. Here we present a Monte Carlo approach to produce probabilistic climate projections, using… Expand
Towards quantifying uncertainty in transient climate change
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AbstractPerturbed physics ensembles (PPEs) have been widely used to assess climate model uncertainties and have provided new estimates of climate sensitivity and parametric uncertainty inExpand
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Constraining uncertainties in climate models using climate change detection techniques
Predictions of 21st century climate by different atmosphere-ocean general circulation models depend on the sensitivities of the models to external radiative forcing and on their rates of heat uptakeExpand
Quantifying the uncertainty in forecasts of anthropogenic climate change
The range of warming rates over the coming 50 years is assessed that is relatively robust to errors in the models' climate sensitivity, rate of oceanic heat uptake or global response to sulphate aerosols as long as these errors are persistent over time. Expand
Quantifying Uncertainties in Climate System Properties with the Use of Recent Climate Observations
We derive joint probability density distributions for three key uncertain properties of the climate system, using an optimal fingerprinting approach to compare simulations of an intermediateExpand
An Observationally Based Estimate of the Climate Sensitivity
Abstract A probability distribution for values of the effective climate sensitivity, with a lower bound of 1.6 K (5th percentile), is obtained on the basis of the increase in ocean heat content inExpand
Causes of climate change over the past 1000 years
  • Crowley
  • Environmental Science, Medicine
  • Science
  • 2000
A 21st-century global warming projection far exceeds the natural variability of the past 1000 years and is greater than the best estimate of global temperature change for the last interglacial. Expand
On summing the components of radiative forcing of climate change
Abstract Radiative forcing is a useful concept in determining the potential influence of a particular mechanism of climate change. However, due to the increased number of forcing agents identifiedExpand
Interpretation of High Projections for Global-Mean Warming
This work interprets the new warming range in probabilistic terms, accounting for uncertainties in emissions, the climate sensitivity, the carbon cycle, ocean mixing, and aerosol forcing, and shows that the probabilities of warming values at both the high and low ends of the TAR range are very low. Expand
Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate Change (IPCC) Emission Scenarios
A coupled physical-biogeochemical climate model that includes a dynamic global vegetation model and a representation of a coupled atmosphere-ocean general circulation model is driven by theExpand
Attribution of twentieth century temperature change to natural and anthropogenic causes
Abstract  We analyse possible causes of twentieth century near-surface temperature change. We use an “optimal detection” methodology to compare seasonal and annual data from the coupledExpand
Causes of twentieth-century temperature change near the Earth's surface
Observations of the Earth's near-surface temperature show a global-mean temperature increase of approximately 0.6 K since 1900 (ref. 1), occurring from 1910 to 1940 and from 1970 to the present. TheExpand