67. Bridging the Climate-corporate Gap: Utilizing GWP* with GWP100 for Livestock Companies' Greenhouse Gas Inventories.

Abstract The global warming potential (GWP) metric on a 100 year basis (GWP100) is currently the most common metric implemented by corporations in their greenhouse gas (GHG) inventories. However, GWP100 cannot adequately account for the short atmospheric lifespan of some GHG, such as CH4 which has a 12-yr atmospheric lifespan. As such, GWP100 is unable to adequately translate GHG emissions to climate warming contributions. More recently, GWP-star (GWP*) has been developed to resolve this issue. The GWP* and GWP100 result in different estimates of climate warming contributions by CH4. With the emergence of GWP* there has been increasing interest in adopting this metric into corporate reporting. However, the 20-year baseline data required to calculate GWP* has limited companies' ability to incorporate GWP* into their current GHG reporting inventories. To bridge the gap between GWP* and corporate accounting we developed a straightforward methodology to enable companies to dual report both GWP* and GWP100 within their inventories. Specifically, the methodology developed a “shadow company” technique that will allow GWP* to be This is a provisional file, not the final typeset article calculated from a specified baseline reporting year and onwards. To realistically model a corporate inventory we developed a mock beef company, titled the Global Beef Company that operated in Brazil, Australia, and the United States. Emission reduction and growth scenarios were modeled over an 80-year timescale. To evaluate the cumulative effect of warming over time, GHG were modeled using cumulative sum of GWP* and GWP100 values. With many companies reporting GHG on an intensity basis, a new metric was formulated entitled Intensity Cumulative where GWP* and GWP100 were both reported on intensity basis. Overall, the paper provides a step-by-step template for dual reporting GWP* and GWP100 on an absolute and intensity basis for GHG corporate accounting.