Arctic News: IPCC Report Climate Change and Land

Friday, August 9, 2019

IPCC Report Climate Change and Land

The IPCC has just issued a special report Climate Change and Land, on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. In its new report 'Climate Change and Land', the IPCC finds that vegan is the best diet to reduce emissions. Sadly, it is yet another missed opportunity to show some integrity.

[ click on image to enlarge ]

Indeed, little or nothing will change as long as the IPCC keeps downplaying the dire situation we're in.

As an example, the IPCC Report uses a very low value of 28 as Global Warming Potential (GWP) for methane, which is totally inappropriate and unacceptable given the rapidity at which the biosphere is deteriorating, given the accelerating pace at which extreme weather events are striking the land all around the world, and given the grim prospects for people worldwide in the absence of rapid and radical change.

The report finds that agriculture, forestry and other land use activities accounted for around 13% of carbon dioxide, 44% of methane, and 82% of nitrous oxide emissions from human activities globally during 2007-2016, representing 23% of total net anthropogenic emissions of greenhouse gases. If emissions associated with pre- and post-production activities in the global food system are included, the emissions could be as high as 37% of total net anthropogenic greenhouse gas emissions.

The Report adds an image showing that annual methane emissions from agriculture had reached some 4Gt CO₂eq in 2016. The IPCC notes that this 4Gt for methane's CO₂-eq is based on a GWP for methane of 28 over 100 years and without climate-carbon feedbacks, taken from its Fifth Assessment Report (AR5), published in 2014.

As said, the Report calculates that net greenhouse gas emissions from agriculture, forestry, and other land use were 23% of people's 2007-2016 emissions when using a GWP of 28 for methane. When using a GWP of 150, that share rises to 31%, as illustrated by the image on the right.

Instead of calculating methane's GWP over 100 years, a very short horizon is appropriate. Moreover, research published in 2016 and 2018 had already found methane to be more potent than IPCC's GWP for methane in AR5, as discussed in a recent post.

When using an appropriate GWP, the percentage of greenhouse gases coming from agriculture (in particular livestock products) increases dramatically, thus rightly highlighting the urgency for governments to act, e.g. by implementing local feebates, such as fees on livestock products and nitrogen fertilizers with revenues used to support soil supplements containing biochar, as recommended in a recent post.