To summarize, climate crisis is the defining issue of the century. Buildup of anthropogenic greenhouse gases (GHGs) in Earth’s atmosphere is driving global heating, while a convergence of global crises threatens to rupture key planetary boundaries beyond which organized human life on Earth would be threatened. Although the human activities which drive these converging crises (for simplicity: the climate crisis) are diverse and complex, the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) offers a high level categorization of the sources of anthropogenic emissions. Yesterday’s piece focused on the energy sector, the largest single contributor to anthropogenic GHG emissions (at 35% in 2010) according to the IPCC. Today’s piece centers the second largest contributor (at 24% in 2010), namely: agriculture, forestry, and other land use (or AFOLU).
The name of this sector (if something so broad can even be called such) more or less speaks for itself, but here’s some text (from page 118 of the AR5 Annexes) describing AFOLU mitigation opportunities that offers further texture regarding the complexity and character of the AFOLU challenges:
Without attempting to get into any details, I’ll just note that the concept of “net emissions” is especially important in attempts to quantify AFOLU contributions to total GHG emissions given that – unlike say the energy sector, which basically only emits GHGs into Earth’s atmosphere – the interplay between land, atmosphere, and human activity is such that AFOLU as constituted can be seen as both emitting and drawing down GHGs to/from Earth’s atmosphere. This sector is of particular interest to me personally (owing in no small part to my love of plants), and I continue to follow with interest and balanced enthusiasm and skepticism efforts to “green” cities, grow more food in urban areas, install green roofs, etc., etc. The rhetoric is often bombastic, and the motivations are sometimes suspect, but as with simple energy efficiency measures – if instituted at scale (see Japan’s Cool Biz initiative) – urban AFOLU offers modest but real emissions-reduction low-hanging fruit.