All ground up: the role of coffee in climate change

At the beginning of August, the International Panel on Climate Change (IPCC) delivered its starkest warning yet on climate change in its sixth Assessment Report (AR). The report highlights, with higher confidence than the previous report (AR5) that, climate change is attributable to human influences in particular carbon dioxide and methane emissions.

Coffee too plays it's role in carbon emissions. IPCC estimates that global agriculture (including coffee production) accounts for 10%-12% of cumulative greenhouse gas emissions.

Carbon Coffee

From farm-to-cup is is estimated that for every kilogram of coffee the associated carbon emissions are approximately 15-20kgs of carbon dioxide equivalent (CO2e). A large potion of the emissions are released from fertilisers used in the farming process and from the supply chain used to ship the goods globally.

All ground up

Interestingly, however, a lesser know emission source is from the used coffee grounds. When the coffee grounds end up in landfill they begin to rot and emit methane into the atmosphere. Methane has a much higher warming potential than CO2. According to the National Greenhouse Accounts Factors published by the Australian Government, methane has a warming potential of a factor of 28 compared to carbon dioxide. The good news is that the half life is much shorter at 10 years.

So by simply keeping our coffee grounds out of the ground (e.g. using as fertilizer on acid-loving plants) this can reduce the impact on global warming!