Which IPCC Tiers does the Cool Farm Tool incorporate? Do you consider Global Warming Potential from the IPCC Assessment Report 4 or 5?

Michaela

For crops, the Cool Farm Tool incorporates Tier 1, Tier 2 and when it comes to N2O emissions and soil carbon sequestration,  a “simple Tier 3” model – as described by Prof. Pete Smith – as it is a multi-factoral empirical model based on Bouwman, which is widely acknowledged in the public domain. The Cool Farm Tool is moving towards Tier 3 whenever possible. Also for livestock it considers Tier 1 and 2 as in dairy and beef. For example manure on pasture is modelled using Tier 1 (1% of N applied becomes N2O), while gross energy demand is Tier 2. There is only some unclarity for other livestock like camels & goats, and we have prepared methodology to update models for pigs & poultry which are not deployed, but would bring that along.

Currently, we are still using the Global Warming Potentials for methane and nitrous oxide from the IPCC Assessment Report 4. However, this is mostly related to the development of versioning of the Cool Farm Tool, which will enable us to operate with different Global Warming Potentials based on the selected version. We are planning to include the new Global Warming Potential values soon.