Development and application of earth system models

Abstract

The global environment is a complex and dynamic system. Earth system modeling is needed to help understand changes in interacting subsystems, elucidate the influence of human activities, and explore possible future changes. Integrated assessment of environment and human development is arguably the most difficult and most important "systems" problem faced. To illustrate this approach, we present results from the integrated global system model (IGSM), which consists of coupled submodels addressing economic development, atmospheric chemistry, climate dynamics, and ecosystem processes. An uncertainty analysis implies that without mitigation policies, the global average surface temperature may rise between 3.5°C and 7.4°C from 1981-2000 to 2091-2100 (90% confidence limits). Polar temperatures, absent policy, are projected to rise from about 6.4°C to 14°C (90% confidence limits). Similar analysis of four increasingly stringent climate mitigation policy cases involving stabilization of greenhouse gases at various levels indicates that the greatest effect of these policies is to lower the probability of extreme changes. The IGSM is also used to elucidate potential unintended environmental consequences of renewable energy at large scales. There are significant reasons for attention to climate adaptation in addition to climate mitigation that earth system models can help inform. These models can also be applied to evaluate whether "climate engineering" is a viable option or a dangerous diversion. We must prepare young people to address this issue: The problem of preserving a habitable planet will engage present and future generations. Scientists must improve communication if research is to inform the public and policy makers better.climate change | energy and environment | climate policy A wide range of everyday human activity affects our environment: food production, transportation, manufacturing, urban development, population growth, supplying potable water, and waste disposal. The environmental effects include climate change, urban air pollution, lowered water quality, land degradation, ecosystem disruption, and human health. The climate issue exemplifies the challenge for sustaining a habitable earth. To forecast climate change and develop sound responses, we need to couple the human and natural components of the earth system. Such integrated assessments have many additional potential benefits: discovery of new interactions among natural and human climate system components, objective assessment of uncertainty in economic and climate projections, critical and quantitative analysis of policy proposals, and understanding connections to other science and policy issues (e.g., air pollution). Today, there are very significant policy debates regarding global climate change within most nations, contentious negotiations under the Framework Convention on Climate Change, and periodic assessments under the Intergovernmental Panel on Climate Change (IPCC) (1-3).Over the past 2 centuries, the concentrations of carbon dioxide and ma...

Modeling plant–water interactions: an ecohydrological overview from the cell to the global scale

“…The request for quantifications of global carbon and water cycles and plant biogeography, especially in the context of understanding the consequences of climate change, was conducive to the development of models able to simulate vegetation dynamics (Box ) on a global scale . These models appear with various names: dynamic global vegetation models (DGVMs), terrestrial biosphere models, terrestrial ecosystem models, and more recently, as vegetation components of ESMs (e.g., Refs ). Here, the term terrestrial biosphere model is used to refer to this family of models .…”

What Do We Learn from the Weather? The New Climate-Economy Literature

“…It can be used to simulate the impacts of different emission scenarios and to assess whether a given carbon tax rate is likely to meet a target to limit warming, but it lacks a damage function and thus cannot be used to solve for the optimal carbon tax. The MIT ITSM model is another well-known example of this type of model (Prinn 2013). 53 The DICE/RICE, PAGE, and FUND models were discussed in detail in the IPCC 4th assessment report and in the U.S. government review of social cost of carbon estimates (Greenstone, Kopits, and Wolverton forthcoming).…”

Impact of Aviation on Climate: FAA’s Aviation Climate Change Research Initiative (ACCRI) Phase II

“…Other models predicted a decrease in HO 2 because of predicted higher NO x as a result of less conversion to other gases or aerosol particle components. Global tropospheric ozone burdens for background ozone range from about 275 Tg for Integrated Global System Modeling framework (IGSM;Sokolov et al 2009;Prinn 2012) Overall, the seven models show large differences in the calculated species composition due to aviation emissions, a part of which is due to differences in their simulated background atmosphere. The offline CTM model results as a group (e.g., CAM4, CAM5, GEOSChem), with fixed prescribed meteorology, tend to be similar in their responses and sensitivities.…”