Search

First steps toward a broad climate agreement, such as the Kyoto Protocol, have focused on less than global geographic coverage. We consider instead a policy that is less comprehensive in term of greenhouse gases (GHGs), including only the non-CO2 GHGs, but is geographically comprehensive. Abating non-CO2 GHGs may be seen as less of a threat to economic development and therefore it may be possible to involve developing countries in such a policy even though they have resisted limits on CO2 emissions. The policy we consider involves a GHG price of about $15 per ton carbon-equivalent (tce) levied only on the non-CO2 GHGs and held at that level through the century. We estimate that such a policy would reduce the global mean surface temperature in 2100 by about 0.55° C; if only methane is covered that alone would achieve a reduction of 0.3° to 0.4° C. We estimate the Kyoto Protocol in its current form would achieve a 0.25° C reduction in 2100 if Parties to it maintained it as is through the century. Furthermore, we estimate the costs of the non-CO2 policies to be a small fraction of the Kyoto policy. Whether as a next step to expand the Kyoto Protocol, or as a separate initiative running parallel to it, the world could well make substantial progress on limiting climate change by pursuing an agreement to abate the low cost non-CO2 GHGs. The results suggest that it would be useful to proceed on global abatement of non-CO2 GHGs so that lack of progress on negotiations to limit CO2 does not allow these abatement opportunities to slip away. [ABSTRACT FROM AUTHOR]

Current climate policies are based on the use of Global Warming Potentials (GWPs) to compare emissions of various greenhouse gases. Yet, from an economic point of view, more efficient methods exist. We compare the potential costs of implementing some long-term goal for stabilization of the climate in three cases: Reduce CO2 emissions only, reduce emissions of the four greenhouse gases CO2, CH4, N2O and SF6 using the standard IPCC GWPs and reduce emissions of the same four gases with efficient and flexible, time dependent metrics. A multi-gas approach with GWPs reduces the costs by 8 percent when compared with CO2 reductions only, whereas the costs may be reduced by an additional 2 percent if using flexible metrics. If compared with the use of GWPs, we find that efficient weights increase the cost savings of including non-CO2 gases in climate policy by 15-40%, depending on the stabilization goal. [ABSTRACT FROM AUTHOR]

I analyse the costs of policies aimed at stabilising global climate change. I show that abatement of all major greenhouse gases is important to the costs of climate policies and that flexible reduction of methane and other non-CO2 gases may reduce costs significantly. The non-CO2 gases offer many low-cost abatement options and this reduces the need for abatement of CO2 to stabilise climate change. Multi-gas flexibility may be important if climate policies reflect not only long-term stabilisation, but also the rate at which the climate changes, as the latter may require large reductions in emissions in the short-term. [ABSTRACT FROM AUTHOR]

When conducting a multi-gas analysis, there are distinct advantages in moving from concentrations to radiative forcing. With the former, it is customary to use Global Warming Potentials (GWPs) for making tradeoffs among greenhouse gases. A number of studies have shown the arbitrariness of this approach and have argued that tradeoffs should be based on the contribution of each gas to achieving a particular target. Focusing on radiative forcing bypasses the need to rely on GWPs and provides for tradeoffs among gases based on their relative value. [ABSTRACT FROM AUTHOR]

This paper examines the role of climate forcing agents other than carbon dioxide using the MiniCAM integrated assessment model for both no-climate-policy and policy emissions scenarios. Non-CO2 greenhouse-gas forcing is dominated by methane and tropospheric ozone. Assumptions about the prevalence of methane recovery and local air pollution controls in the no-policy cases are a critical determinant of methane and ozone-precursor emissions. When these factors are considered, emissions are substantially reduced relative to earlier estimates. This reduces their potential as climate mitigation agents through specific climate policies. Nevertheless, the addition of non-CO2 greenhouse gas and ozone precursor abatement options significantly reduces mitigation costs in the first half of the 21st century (by up to 40%) compared to the case where only CO2 abatement options are pursued. While the influences of aerosols are small by the end of the century, there is a significant interaction in the early 21st century between policies to reduce CO2 emissions and SO2 emissions, even in the presence of SO2-related pollution control policies. The attendant reduced aerosol cooling can more than offset the reduction in warming that accrues from reduced CO2. When non-CO2 gases are included in the policy, the net effect is that global-mean climate change to 2050 is practically unaffected by mitigation policy. [ABSTRACT FROM AUTHOR]

In this paper we examine the interaction between technology policy and its impact on the full basket of worldwide greenhouse emissions over the 21st century. The heart of the analysis is the Argonne National Laboratory's AMIGA Modeling System, a technology rich, general equilibrium model that (depending on data availability) characterizes as many as 200 sectors of the regional economies. We suggest in this paper that technologies and technology policies exist which could reduce carbon emissions enough to achieve stabilization targets at relatively modest costs given the size of the world economy. This can be accomplished largely through harnessing market forces and creating incentives with the use of efficient prices on greenhouse gas emissions, combined with complementary programs and policies to reduce market failures and to promote new technology improvements and investments. [ABSTRACT FROM AUTHOR]

The Second Generation Model (SGM) was developed to analyze policies designed to reduce greenhouse gas emissions. This paper documents how greenhouse gas emissions are calculated in the SGM, and provides an application to several Energy Modeling Forum scenarios that stabilize radiative forcing by using policies that either exclusively limit CO2 emissions or include both CO2 and non-CO2 greenhouse gases. Additionally, this paper discusses an extension which includes advanced fossil generating technologies with CO2 capture and storage in the USA region of the SGM. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to assess and compare regional welfare costs associated with alternative multi-gas strategies for a stabilization of global greenhouse gases (GHG) emissions in the long run. Mitigation costs of non-CO2 greenhouse gases are integrated into a multi-region multi-country CGE model of the world economy. Calibrations are based on GHG emissions projections from, and marginal abatement cost curves provided by, the EMF21 working group for the six greenhouse gases. We find that the introduction of non-CO2 GHGs in the mitigation strategy reduces significantly the welfare cost of a long term emissions stabilization policy but that benefits vary across regions. We also find that the various possible rules of emission quotas allocation may have large effects on the burden sharing among regions. [ABSTRACT FROM AUTHOR]