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Stronger negative cloud feedback due to a shift from supercooled clouds to warm clouds under climate warming weakens extratropical cloud feedback and impacts climate sensitivity and uncertainty in recent climate models, suggests an analysis of satellite observations and simulations.

Marine low clouds cool the planet, but their response to warming is uncertain and dominates the spread in model-based climate sensitivities. Observational constraints suggest smaller cloud feedbacks than previously reported and imply a more moderate climate sensitivity.

Global mean surface and tropospheric temperatures have shown slower warming since 1998 than found in climate model simulations. A detailed analysis of observations and climate model simulations suggests that the observed influence of volcanic eruptions on tropospheric temperature has been significant, and that the discrepancy between climate simulations and observations is reduced by up to 15% when twenty-first century volcanic eruptions are accounted for in the models.

Cloud feedbacks strongly influence the magnitude of global warming. Climate model simulations show that these feedbacks vary strongly as the spatial patterns of sea surface temperatures change over time.

Earth’s energy budget depends on the global sea surface temperature pattern, which is currently counteracting warming more strongly than expected in the future. Including this pattern effect in projections causes committed warming with present-day forcing to exceed the Paris goals, implying less leeway than anticipated.

CMIP6 models simulate higher and more accurate cloud liquid water fraction relative to CMIP5, but both ensembles overestimate warm cloud precipitation. Correcting these warm cloud processes in a model exposes compensating biases large enough to offset CMIP5–CMIP6 climate sensitivity differences.

The sixth and latest IPCC assessment weights climate models according to how well they reproduce other evidence. Now the rest of the community should do the same.

Since 1990, the wide range in model-based estimates of equilibrium climate warming has been attributed to disparate cloud responses to warming. However, major progress in our ability to understand, observe, and simulate clouds has led to the conclusion that global cloud feedback is likely positive.

Satellite records show that the global pattern of cloud changes between the 1980s and the 2000s are similar to the patterns predicted by models of climate with recent external radiative forcing, and that the primary drivers of the cloud changes appear to be increasing greenhouse gas concentrations and a recovery from volcanic radiative cooling.

Climate science celebrates three 40th anniversaries in 2019: the release of the Charney report, the publication of a key paper on anthropogenic signal detection, and the start of satellite temperature measurements. This confluence of scientific understanding and data led to the identification of human fingerprints in atmospheric temperature.

The magnitude of global precipitation increase predicted by climate models has a large uncertainty that has been difficult to constrain, but much of the range in predictions is now shown to arise from shortcomings in the modelling of atmospheric absorption of shortwave radiation; if the radiative transfer algorithms controlling the absorption were more accurate, the model spread would narrow and the mean estimate could be about 40% lower.