Number: RS22970
Title: Are Carbon Dioxide Emissions Rising More Rapidly Than Expected?
Authors: Jane A. Leggett and Jeffrey Logan, Resources, Science, and Industry Division 
Abstract: At least one recent report and numerous news articles suggest that carbon dioxide (CO2) emissions are rising more rapidly than expected. This contention is often made by comparing recent emissions estimates with the greenhouse gas (GHG) scenarios published by the Intergovernmental Panel on Climate Change (IPCC) in 2000. While CO2 emissions associated with human activities continue to rise - and may be worthy of alarm because of their influence on climate change - any short-term comparisons between actual emissions and IPCC scenarios miss the mark. First, the IPCC scenarios explicitly are not predictions. Second, the IPCC scenarios are meant to represent different possible GHG trajectories over many decades, and represent smooth emissions paths averaged over at least 10 years. Just as the actual weather over a few years is not necessarily representative of long-term climate, variability of emissions over one or several years is not necessarily representative of long-term trends. Nonetheless, monitoring of CO2 emissions and concentrations, and analysis of the factors driving changes, is important to designing and evaluating policies to address climate change.
Pages: 6
Date: October 17, 2008