PNNL

Abstract

The implications of anthropogenic climate change for the environment and society depend not only on the response of the Earth system to changes in atmospheric composition and land cover, but also on human responses. These responses are often classified into “adaptation”—changes in activities, infrastructure, or systems tailored to new climate conditions—and “mitigation”—actions to reduce net greenhouse gas emissions. Increasingly, analysts and researchers are examining adaptation and mitigation together, as both will involve changes in technology, economies, lifestyles, and policy that will interact in important ways geographically and sectorally. All of these processes—across the socioeconomic, environmental, and climate domains—are subject to extensive uncertainties. Scenarios are used by researchers and other analysts to evaluate how human choices about mitigation and adaption to future climate change will fare under uncertain future socioeconomic and climate conditions. Scenarios used in climate research and analysis cover a wide range of topics including human activities and systems, emissions of greenhouse gases and other pollutants, land use change, future climate conditions, environmental factors such as sea level rise and air/water quality, and attributes of society that influence vulnerability and resilience to climate change. This paper provides a brief overview of a new “parallel process” for developing and applying scenarios for climate change research and assessment. This parallel process was developed through a series of meetings and research papers from 2006-2010 and is described in the report of an expert meeting of the Intergovernmental Panel on Climate