The research on earth system science conducted within CMI facilitates its integration efforts. The Pacala and Oppenheimer groups use state-of-the art models to provide descriptions of climate risks that are relevant to policymakers.


Focus on short-term climate variability

To help anticipate the risks of nearterm climate change, in 2012 bp agreed to sponsor a new research program at Princeton entitled “Climate Variability over the Next 25 Years.” Headed by Steve Pacala and Elena Shevliakova, the program involves collaborative research among bp, CMI, GFDL and the bp-sponsored team at Imperial College. The researchers are using high-resolution climate models to predict climate variability, changes in climate variability, and impacts of climate variability over the next quarter century.

Research highlights for 2013 include:

  • An investigation of the current temperature pause/hiatus. The team believes the hiatus could be related to the Atlantic Meridional Oscillation (AMO) and is working to develop a tool by this fall to estimate when this hiatus might end.
  • Completion of an analysis of Chinese drought/heat waves. Model results have not accurately reproduced historic patterns, which has led the group to hypothesize that aerosols were deficient in the model, particularly in China. They have built an aerosol and dust package into a high-resolution model to solve the problem.
  • Development of a tool for analysis of extreme precipitation data. A new extreme precipitation data set has been created and the teams are working to produce an analysis documenting patterns of extreme precipitation worldwide at 25 km resolution.

Future plans include providing global predictions for extreme precipitation, predictions for city-generated weather (e.g., heat waves) globally through 2050, and production of a refined drought analysis.


Assessing the risk of sea level rise

In recent years the Oppenheimer group’s focus has been on creating projections for sea-level rise that account for all relevant physical processes and are useful for risk management.

Quantifying the risk associated with future sea level rise requires the projection and aggregation of many physical processes – including ocean thermal expansion, ice sheet and glacier mass loss, and vertical land motion. Chris Little and Michael Oppenheimer remain focused on comprehensively and consistently including these processes in sea level projections, providing a more conducive basis for a risk management approach to climate change.



This year, projections derived using the researchers’ novel approach to quantifying future Antarctic ice loss were heavily cited in the IPCC’s Fifth Assessment report. The group continues to develop this framework, with ongoing efforts designed to include: 1) changes in the Greenland ice sheet mass balance; 2) the solid earth and gravitational responses that modulate sea level changes at the local level; and 3) new constraints from process-based ice sheet models, smaller-scale observations of ice
loss, paleo-sea-level observations, and expert judgment.

Along with former Oppenheimer post-doc Robert Kopp, they are generating fully probabilistic projections of sea level rise at global tide gauge locations (Figure 1). These projections – which account for processes that result in sea level changes over annual to decadal timescales – are being combined with projections of short-term sea level variability (storm surge) developed by other Princeton researchers. The merged projections will be used to generate a risk assessment of coastal flooding at four coastal tide gauge locations on the East coast of the U.S. through the year 2100.

Figure 1. Median projection (top, in meters) and width of 17th-83rd percentile range (bottom, in meters) of local sealevel rise at global sites in 2100 under RCP 8.5 (median global sea level rise of 0.78 meters). From Kopp et al. (submitted).