What is methane “worth” to the climate, and what are the implications for our food system?

Methane is a powerful greenhouse gas, which contributes significantly to climate change. However, it is also a relatively short-lived gas, so it affects the climate in a fundamentally different way to CO2. This distinction between short- and long-lived greenhouse gases can cause problems if climate emissions metrics (which are used to compare different emissions) are inappropriately applied. About two-thirds of the anthropogenic sources of methane are from agriculture and waste. How these emissions of methane are (mis-)represented makes a big difference to estimates of a food’s carbon footprint. This in turn has implications for the types of agricultural production system we support, and how we might prioritise potential mitigations.