Publications by Raymond Pierrehumbert

Climate Intervention: Reflecting Sunlight to Cool Earth

National Academies Press, 2015

Committee on Geoengineering Climate, RT Pierrehumbert

Weather modification, which could also be called “weather intervention,” is the intentional alteration of the composition, behavior, or dynamics of the atmosphere occurring over a specified area and time period to accomplish a particular goal ...

Climate Intervention Carbon Dioxide Removal and Reliable Sequestration

National Academies Press, 2015

Committee on Geoengineering Climate, RT Pierrehumbert

Carbon Dioxide Removal and Reliable Sequestration Committee on Geoengineering Climate: Technical Evaluation and Discussion of Impacts, Board on Atmospheric Sciences and Climate, Ocean Studies Board, Division on Earth and Life ...

A simple carbon cycle representation for economic and policy analyses

CLIMATIC CHANGE 126 (2014) 319-335

MJ Glotter, RT Pierrehumbert, JW Elliott, NJ Matteson, EJ Moyer

Short-Lived Climate Pollution


RT Pierrehumbert



R Wordsworth, R Pierrehumbert



RD Wordsworth, RT Pierrehumbert

Hot climates, high sensitivity.

Proceedings of the National Academy of Sciences of the United States of America 110 (2013) 14118-14119

RT Pierrehumbert

The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets.

Astrobiology 13 (2013) 715-739

AL Shields, VS Meadows, CM Bitz, RT Pierrehumbert, MM Joshi, TD Robinson

Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. In this study, we explored this effect with a one-dimensional (1-D), line-by-line, radiative transfer model to calculate broadband planetary albedos as input to a seasonally varying, 1-D energy balance climate model. A three-dimensional (3-D) general circulation model was also used to explore the atmosphere's response to changes in incoming stellar radiation, or instellation, and surface albedo. Using this hierarchy of models, we simulated planets covered by ocean, land, and water-ice of varying grain size, with incident radiation from stars of different spectral types. Terrestrial planets orbiting stars with higher near-UV radiation exhibited a stronger ice-albedo feedback. We found that ice extent was much greater on a planet orbiting an F-dwarf star than on a planet orbiting a G-dwarf star at an equivalent flux distance, and that ice-covered conditions occurred on an F-dwarf planet with only a 2% reduction in instellation relative to the present instellation on Earth, assuming fixed CO(2) (present atmospheric level on Earth). A similar planet orbiting the Sun at an equivalent flux distance required an 8% reduction in instellation, while a planet orbiting an M-dwarf star required an additional 19% reduction in instellation to become ice-covered, equivalent to 73% of the modern solar constant. The reduction in instellation must be larger for planets orbiting cooler stars due in large part to the stronger absorption of longer-wavelength radiation by icy surfaces on these planets in addition to stronger absorption by water vapor and CO(2) in their atmospheres, which provides increased downwelling longwave radiation. Lowering the IR and visible-band surface ice and snow albedos for an M-dwarf planet increased the planet's climate stability against changes in instellation and slowed the descent into global ice coverage. The surface ice-albedo feedback effect becomes less important at the outer edge of the habitable zone, where atmospheric CO(2) could be expected to be high such that it maintains clement conditions for surface liquid water. We showed that ∼3-10 bar of CO(2) will entirely mask the climatic effect of ice and snow, leaving the outer limits of the habitable zone unaffected by the spectral dependence of water ice and snow albedo. However, less CO(2) is needed to maintain open water for a planet orbiting an M-dwarf star than would be the case for hotter main-sequence stars.

Robust elements of Snowball Earth atmospheric circulation and oases for life


DS Abbot, A Voigt, D Li, G Le Hir, RT Pierrehumbert, M Branson, D Pollard, DDB Koll

Strange news from other stars

NATURE GEOSCIENCE 6 (2013) 81-83

RT Pierrehumbert

Hydrogen-nitrogen greenhouse warming in Earth's early atmosphere.

Science (New York, N.Y.) 339 (2013) 64-67

R Wordsworth, R Pierrehumbert

Understanding how Earth has sustained surface liquid water throughout its history remains a key challenge, given that the Sun's luminosity was much lower in the past. Here we show that with an atmospheric composition consistent with the most recent constraints, the early Earth would have been significantly warmed by H(2)-N(2) collision-induced absorption. With two to three times the present-day atmospheric mass of N(2) and a H(2) mixing ratio of 0.1, H(2)-N(2) warming would be sufficient to raise global mean surface temperatures above 0°C under 75% of present-day solar flux, with CO(2) levels only 2 to 25 times the present-day values. Depending on their time of emergence and diversification, early methanogens may have caused global cooling via the conversion of H(2) and CO(2) to CH(4), with potentially observable consequences in the geological record.

Cumulative Carbon and Just Allocation of the Global Carbon Commons

Chicago Journal of International Law 13 (2013) 12

RT Pierrehumbert

The Warming Papers The Scientific Foundation for the Climate Change Forecast

John Wiley & Sons, 2013

D Archer, R Pierrehumbert

Global warming is arguably the defining scientific issue of modern times, but it is not widely appreciated that the ... together the classic scientific papers that are the scientific foundation for the forecast of global warming and its consequences.

Nonlinear Phenomena in Atmospheric and Oceanic Sciences

Springer, 2013

G Carnevale, RT Pierrehumbert

This IMA Volume in Mathematics and its Applications NONLINEAR PHENOMENA IN ATMOSPHERIC AND OCEANIC SCIENCES is based on the proceedings of a workshop which was an integral part of the 1989-90 IMA program on "Dynamical Systems and their ...

Atmospheric composition, irreversible climate change, and mitigation policy.

in Climate Science for Serving Society Research, Modeling and Prediction Priorities, Springer Science & Business Media (2013) 15

S Solomon, RT Pierrehumbert, HD matthews, JS Daniel, P Friedlingstein

This volume offers a comprehensive survey and a close analysis of efforts to develop actionable climate information in support of vital decisions for climate adaptation, risk management and policy.

Cumulative carbon as a policy framework for achieving climate stabilization.

Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 370 (2012) 4365-4379

HD Matthews, S Solomon, R Pierrehumbert

The primary objective of the United Nations Framework Convention on Climate Change is to stabilize greenhouse gas concentrations at a level that will avoid dangerous climate impacts. However, greenhouse gas concentration stabilization is an awkward framework within which to assess dangerous climate change on account of the significant lag between a given concentration level and the eventual equilibrium temperature change. By contrast, recent research has shown that global temperature change can be well described by a given cumulative carbon emissions budget. Here, we propose that cumulative carbon emissions represent an alternative framework that is applicable both as a tool for climate mitigation as well as for the assessment of potential climate impacts. We show first that both atmospheric CO(2) concentration at a given year and the associated temperature change are generally associated with a unique cumulative carbon emissions budget that is largely independent of the emissions scenario. The rate of global temperature change can therefore be related to first order to the rate of increase of cumulative carbon emissions. However, transient warming over the next century will also be strongly affected by emissions of shorter lived forcing agents such as aerosols and methane. Non-CO(2) emissions therefore contribute to uncertainty in the cumulative carbon budget associated with near-term temperature targets, and may suggest the need for a mitigation approach that considers separately short- and long-lived gas emissions. By contrast, long-term temperature change remains primarily associated with total cumulative carbon emissions owing to the much longer atmospheric residence time of CO(2) relative to other major climate forcing agents.

Clouds and Snowball Earth deglaciation


DS Abbot, A Voigt, M Branson, RT Pierrehumbert, D Pollard, G Le Hir, DDB Koll

Climate of the Neoproterozoic


RT Pierrehumbert, DS Abbot, A Voigt, D Koll

Sea glacier flow and dust transport on Snowball Earth


D Li, RT Pierrehumbert

Some fine points on radiative forcing Reply

PHYSICS TODAY 64 (2011) 12-12

RT Pierrehumbert