Allocation of global temperature change to consumers

Abstract

Climate policy is generally concerned with the mitigation of well-mixed greenhouse gases, allocated to the country where the emissions occur, and with different emissions weighted together with the Global Warming Potential (GWP) using a 100 year time horizon. This perspective is not unique. Recent research has considered the inclusion of Short-Lived Climate Forcers (SCLFs), allocated emissions to the consumption of goods and services, and used alternative emissions metrics. Here, for the first time, we combine these alternative perspectives to explore the potential policy implications of three alternative framings: 1) using the Global Temperature change Potential (GTP) to directly link current emissions to temperature change, 2) including SLCFs that have both warming and cooling effects on climate, and 3) allocating emissions to consuming sectors and regions. Collectively, we use these three aspects to allocate the future temperature response to the consumption of goods and services in a given year. We show, in order of importance, that the method of allocating emissions to economic sectors is the most important, followed by the emission metric (including time-horizon), and then the mix of short-lived and well-mixed climate forcers. The consumption perspective reallocates emissions from electricity and manufacturing to service sectors, which suggests different policy options for demand and supply. The net effect of multiple pollutants and GTP significantly change the importance of the sectors compared to when only considering CO₂ or when using the GWP. We argue that a focus on only one accounting system and framing in climate policy can potentially limit consideration of mitigation options to a reduced set of activities, and thereby missing significant opportunities for mitigation in other aspects.