Climate Primer #8: The Seventh Planetary Boundary – Land System Change

To summarize, climate crisis is the defining issue of the century. Buildup of anthropogenic greenhouse gases 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 will be threatened) including: stratospheric ozone depletion, biodiversity loss, toxic substance contamination, climate change (the defining sub-category of climate crisis), ocean acidification, and freshwater consumption.

Today’s post centers “land system change” (sometimes also called land use change, or, cumbersomely – in the whimsical parlance of the technocrats – land use, land use change, and forestry, or LULUCF, which is pronounced “loo-loo-sef”) which the Stockholm Resilience Center characterizes as follows:

Land is converted to human use all over the planet. Forests, grasslands, wetlands and other vegetation types have primarily been converted to agricultural land. This land-use change is one driving force behind the serious reductions in biodiversity, and it has impacts on water flows and on the biogeochemical cycling of carbon, nitrogen and phosphorus and other important elements. While each incident of land cover change occurs on a local scale, the aggregated impacts can have consequences for Earth system processes on a global scale. A boundary for human changes to land systems needs to reflect not just the absolute quantity of land, but also its function, quality and spatial distribution. Forests play a particularly important role in controlling the linked dynamics of land use and climate, and is the focus of the boundary for land system change.

This description does an especially good job of establishing the fundamental interconnectedness of the various planetary boundaries, as the SRC points out that land system change is not only a key driver of biodiversity loss and extinctions of non-human species (and, I’ll add, a key driving force, in tandem with corporate agribusiness, of the emergence of zoonotic and other novel pathogens), but also plays a key role in the cycles of not only carbon (and hence has a significant, and often overlooked, impact on climate change) but nitrogen and phosphorous (which latter two cycles, together, I’ll address tomorrow, and which, in turn, have a major impact on the health of marine ecosystem and oceanic nutrient balances). Additionally, certain forms of land system change are, obviously, connected with the release of toxic substances, and, on top of all of these technical factors, there’s also the spiritual and aesthetic consideration, which can be summed up, in the words of Joni Mitchell: “Don’t it always seem to go, that you don’t know what you got ’til it’s gone.”

We should be working against the defeatism and regret embedded in her lyric. Today’s bonus recommendation is another short piece of mine (also published today), the title of which speaks for itself: “Public Schools in Public Parks: Reopening School Indoors Is COVID Suicide for NYC. Thankfully, We Have an Alternative.” Thanks for reading.