Raymond T. Pierrehumbert is Halley Professor of Physics at the University of Oxford. He was a lead author on the IPCC Third Assessment Report, and co-author on several National Research Council reports concerning climate change. He was awarded a John Simon Guggenheim Fellowship in 1996, which was used to launch collaborative work on the climate of Early Mars with collaborators in Paris. He is a Fellow of the American Geophysical Union, and of the American Academy of Arts and Sciences, and has been named Chevalier de l'Ordre des Palmes Académiques by the Republic of France. Pierrehumbert's central research interests concern the physics of Earth’s climate over time, as well as the climates of planets in our solar system and the exoplanets beyond.
Despite all the hype, geoengineering would not be simple or easy, or a one-time solution, or buy us any time. Instead, geoengineering would be a difficult undertaking that humanity would have to commit to essentially forever—and still not fix the underlying problem. Assuming it even works.
Bringing global warming to a halt requires that worldwide net emissions of carbon dioxide be brought to essentially zero; the sooner this occurs, the less warming our descendants for the next 1000 years and more will need to adapt to.
Lynn EdenRobert RosnerRod EwingLawrence M. KraussSivan KarthaThomas R. PickeringRaymond T. PierrehumbertRamamurti RajaramanJennifer SimsRichard C. J. SomervilleSharon SquassoniDavid Titley
In keeping the hands of the Doomsday Clock at three minutes to midnight, the members of the Bulletin of the Atomic Scientists Science and Security Board mean to make a clear statement: The world situation remains highly threatening to humanity, and decisive action to reduce the danger posed by nuclear weapons and climate change is urgently required.
Lynn EdenRobert RosnerRod EwingSivan KarthaEdward "Rocky" Kolb Lawrence M. KraussLeon LedermanRaymond T. PierrehumbertM. V. RamanaJennifer SimsRichard C. J. SomervilleSharon SquassoniElizabeth J. WilsonDavid TitleyRamamurti Rajaraman
Today, more than 25 years after the end of the Cold War, the members of the Bulletin of the Atomic Scientists Science and Security Board have looked closely at the world situation and found it so threatening that the hands of the Doomsday Clock must once again be set at three minutes to midnight.