Hot Climates, High Sensitivity. Pierrehumbert, R. T. 110(35):14118–14119.
Hot Climates, High Sensitivity [link]Paper  doi  abstract   bibtex   
Climate sensitivity is the Holy Grail of climate science; because CO2 is one of the principal control knobs for climate, sensitivity to changes in atmospheric CO2 concentration is of particular interest. This sensitivity is typically characterized by the change in global mean temperature per doubling of concentration. Because the determination of climate sensitivity is plagued by uncertainties about the operation of various feedbacks in the climate system – notably cloud feedback – it is natural to look to the past for clues about how well we can model those feedbacks. The chilly climate of the Last Glacial Maximum has been extensively exploited for this purpose (1), but the high CO2 hothouse climates such as the Pliocene (∼5 Mya) or Eocene (∼55 Mya) may be better analogs for where we are headed with our present adventure in turning fossil fuels into atmospheric CO2. In this issue, Caballero and Huber (2) throw some cold water on this hot topic by providing evidence that hothouse states may have different climate sensitivity per doubling of CO2 than the present state. None of this means that study of past hot climates is worthless in the Grail quest; it means only that the Parsifals of climate will have to work harder to extract the treasure. Better information about the past wouldn't hurt either. As Caballero and Huber note, there have already been great strides in understanding the magnitude and pattern of warmth in hothouse climates, which have helped resolve some earlier modeling paradoxes, but much remains to be done. In particular, narrowing the broad error bars on past atmospheric CO2 is crucial to relating these climates to what is going on at present.
@article{pierrehumbertHotClimatesHigh2013,
  title = {Hot Climates, High Sensitivity},
  author = {Pierrehumbert, R. T.},
  date = {2013-08},
  journaltitle = {Proceedings of the National Academy of Sciences},
  volume = {110},
  pages = {14118--14119},
  issn = {1091-6490},
  doi = {10.1073/pnas.1313417110},
  url = {https://doi.org/10.1073/pnas.1313417110},
  abstract = {Climate sensitivity is the Holy Grail of climate science; because CO2 is one of the principal control knobs for climate, sensitivity to changes in atmospheric CO2 concentration is of particular interest. This sensitivity is typically characterized by the change in global mean temperature per doubling of concentration. Because the determination of climate sensitivity is plagued by uncertainties about the operation of various feedbacks in the climate system -- notably cloud feedback -- it is natural to look to the past for clues about how well we can model those feedbacks. The chilly climate of the Last Glacial Maximum has been extensively exploited for this purpose (1), but the high CO2 hothouse climates such as the Pliocene (∼5 Mya) or Eocene (∼55 Mya) may be better analogs for where we are headed with our present adventure in turning fossil fuels into atmospheric CO2. In this issue, Caballero and Huber (2) throw some cold water on this hot topic by providing evidence that hothouse states may have different climate sensitivity per doubling of CO2 than the present state. None of this means that study of past hot climates is worthless in the Grail quest; it means only that the Parsifals of climate will have to work harder to extract the treasure. Better information about the past wouldn't hurt either. As Caballero and Huber note, there have already been great strides in understanding the magnitude and pattern of warmth in hothouse climates, which have helped resolve some earlier modeling paradoxes, but much remains to be done. In particular, narrowing the broad error bars on past atmospheric CO2 is crucial to relating these climates to what is going on at present.},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-12661288,climate-change,cloudiness,communicating-uncertainty,feedback,overwhelming-uncertainty,paleo-climate,scientific-communication,uncertainty},
  number = {35}
}

Downloads: 0