Open AccessThe integrated global temperature change potential (iGTP) and relationships between emission metrics
Author(s) -
Glen P. Peters,
Borgar Aamaas,
Terje Berntsen,
Jan S. Fuglestvedt
Publication year - 2011
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/6/4/044021
Subject(s) - global temperature , greenhouse gas , metric (unit) , global warming , time horizon , environmental science , kyoto protocol , tonne , range (aeronautics) , climate change , econometrics , economics , mathematics , mathematical optimization , chemistry , engineering , ecology , operations management , organic chemistry , biology , aerospace engineering
The Kyoto Protocol compares greenhouse gas emissions (GHGs) using the global warming potential (GWP) with a 100 yr time-horizon. The GWP was developed, however, to illustrate the difficulties in comparing GHGs. In response, there have been many critiques of the GWP and several alternative emission metrics have been proposed. To date, there has been little focus on understanding the linkages between, and interpretations of, different emission metrics. We use an energy balance model to mathematically link the absolute GWP, absolute global temperature change potential (AGTP), absolute ocean heat perturbation (AOHP), and integrated AGTP. For pulse emissions, energy conservation requires that AOHP = AGWP − iAGTP/λ and hence AGWP and iAGTP are closely linked and converge as AOHP decays to zero. When normalizing the metrics with CO 2 (GWP, GTP, and iGTP), we find that the iGTP and GWP are similar numerically for a wide range of GHGs and time-horizons, except for very short-lived species. The similarity between the iGTP X and GWP X depends on how well a pulse emission of CO 2 can substitute for a pulse emission of X across a range of time-horizons. The ultimate choice of emission metric(s) and time-horizon(s) depends on policy objectives. To the extent that limiting integrated temperature change over a specific time-horizon is consistent with the broader objectives of climate policy, our analysis suggests that the GWP represents a relatively robust, transparent and policy-relevant emission metric.