The Global Temperature Potential (GTP) has recently been proposed as an alternative to the Global Warming Potential (GWP). Using two different Earth Models of Intermediate Complexity, we show that the solution to the 100-year sustained GTP for methane is significantly larger than the equivalent GWP due to the inclusion of future changes in greenhouse gas concentrations in the reference scenario and different atmospheric chemistry assumptions. This result suggests that methane reductions may be undervalued when using GWPs, but the policy implications depend on how the objectives of greenhouse gas policy are defined.

© 2012 Springer Science+Business Media B.V.