Uncertainty in the predictions of the climate response to rising levels of greenhouse gases

The range of possibilities for future climate evolution needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty. Statistical estimates of model response uncertainty, based on observations of recent climate change admit climate sensitivities—defined as the equilibrium response of global mean temperature to doubling levels of atmospheric carbon dioxide—substantially greater than 5 K. But such strong responses are not used in ranges for future climate change because they have not been seen in general circulation models. Here we present results from the 'climateprediction.net' experiment, the first multi-thousand-member grand ensemble of simulations using a general circulation model and thereby explicitly resolving regional details. We find model versions as realistic as other state-of-the-art climate models but with climate sensitivities ranging from less than 2 K to more than 11 K. Models with such extreme sensitivities are critical for the study of the full range of possible responses of the climate system to rising greenhouse gas levels, and for assessing the risks associated with specific targets for stabilizing these levels

Learning-Based Project Reviews: Observations and Lessons Learned from the Kennedy Space Center

This research focuses on understanding and developing best practices for effective “learning-based program/project reviews” (LBPRs). LBPRs are defined as program/project reviews that provide an opportunity to learn while sharing status for project control. These LBPRs aim to be an evolution from the traditional status and control reviews to an improvement conversation that drives both learning and improvement within the project environment. LBPRs are important because they provide the real-time, routine opportunity to create, capture, share, and apply both tacit and explicit knowledge throughout a project life-cycle—not just during “lessons learned” at project closeout. Some organizations do complete lessons learned throughout the life cycle of the project. To accomplish this research, an action research approach was implemented using NASA programs and organizations associated with the Kennedy Space Center. © 2005 by the American Society for Engineering Management