The Intergovernmental Panel on Climate Change recently released a draft publication on Climate Change and Land Use . The report, which includes hundreds of scientist co-authors, examines risk across 5 possible future scenarios/paths and identifies key issues–specifically, desertification, land degradation, and compromised food security–that we can expect to see in a hotter world. Out of morbid curiosity and with some intellectual trepidation, I attempted to read it. Below is a quick layperson summary of some of the report’s conclusions, as well as some light editorializing on how terrifying this brave new world promises to be, and links to all the other articles I had to read to make sense of this report.
Land degradation is a catch-all term for the unwinding of ecological vibrancy and biological productivity across a large and varying group of environments. This report broadly defines land degradation as ‘a negative trend in land condition…caused by human-induced processes’ and resulting in a reduction of biological productivity, ecological integrity, or value to humans. Many conditions qualify as land degradation, such as deforestation, permafrost thaw, coastal erosion, and the loss of peat soils, a major carbon sink. The IPCC reports that 25% of the earths non-ice covered surface is currently experiencing land degradation, and that the majority of those affected (from 1.3 to 3.2 billion people) are among the world’s poorest. They predict that long term changes in the quality of land will not only drive humans out of historical coastal settlements, where climate related disaster events like floods are on the rise, but will also cascade though our supply chains and networks, affecting the resource stability of non-coastal environments that are nevertheless linked to disaster-prone communities through economic, social, or political ties.
Finally, land degradation has specifically meant an inability to build and replace nutrient rich soils as fast as they are being depleted. (ie, soil loss exceeds soil formation–spoiler alert, this is bad for food security). Add to this the conversion of cropland to other uses, such as the large-scale production of biomass for fuel and alternative energy (think ethanol) in an effort to satiate energy demand, and you see a perfect storm of competing and mutually exclusive uses duking it out for space in the hinterland. Unsurprisingly, this will have ‘potentially serious’ consequences for agricultural security. Ever hopeful, the IPCC names, among those efforts that are proven to reverse land degradation: “[land] tenure reform…payments for ecosystem services, participatory integrated land use planning, [and] farmer networks and rural advisory services.” In other words, the report links sustainable and resilient land practices to horizontal, community led management of land and the disaggregation of land ownership and control. Anarchists among us, rejoice.
Desertification is precisely what it sounds like–the degrading of terrestrial ecosystems into arid and semi-arid conditions (drylands). Desertification is a form of land degradation and is in some cases it’s most extreme and final stage. Drylands already cover 46% of the earths land surface, and that number is expanding due to climate change. While some drylands are functioning ecosystems and some 3 billion people live in drylands, the creep of aridification and desert conditions is reducing the human carrying capacity of environments that were perviously more hospitable to us. The conversion of other land use types (forest, prairie) to agricultural land can hasten the desertification process through the aforementioned soil degradation and erosion, species replacement, and other factors. While scientists debate whether or not desertification can be reversed, the IPCC treats these environments with a separate and dedicated chapter in part because they are the harshest and most challenging places in the world to live. Desertification also has a feedback relationship to climate change, in which the loss of vegetative groundcover reduces carbon absorption as well as the ability to retain water. Finally, increased desertification has been associated with higher dust storm activity, which causes damage to transportation systems, disrupts sun/wind energy harvesting infrastructure and contributes to poor air quality and respiratory illness. In short, the future is starting to look a lot like Dune.
All, the terror motherload. Food security is where the feedback between unsustainable land management and climate change will emerge as a major pain point in nearly all future scenarios envisioned in this report, despite recent and significant successes in feeding world populations in the 20th century. The IPCC reports that “Since 1961, food supply per capita has increased more than 30%, accompanied by greater use of nitrogen fertilizer (increase of about 800%) and water resources for irrigation (increase of more than 100%).” Somewhat ironically, it is increased agricultural productivity from these technological innovations, which underpin our current global food system, that is “both a major driver of climate change and increasingly vulnerable to it (from production, transport, and market activities).” Due to previously mentioned issues with soil and water, as well as shifting climate zones, the change and distribution of pests and diseases, and the rise of disaster events, agricultural productivity is projected to decline, particularly in tropical and semi-tropical regions. Declines in productivity are expected to influence food pricing, and the IPCC estimates cereal prices will rise anywhere from 1% to a whooping 29% by 2050. Food quality will also play a role: while rising CO2 extends growing seasons and thus may increase the number of plants potentially cultivated in some areas, elevated CO2 levels also lowers the nutritional quality of food.
Indeed, as far as food security goes, it is a game of running even just to stand still. “Given the current system, the FAO estimates that there is a need to produce about 50% more food by 2050 in order to feed the increasing world population (FAO 2018a).” In short, though our most recent round of technological innovation advanced the Malthusian population curve well above the greatest heights ever imagined by our Enlightenment-Age ancestors, we will need still more technological innovation, as well as substantial changes in our current farming and distribution models, if we hope to collectively survive the century as an intact species. Yet it’s a tricky issue. Agricultural activities have always been a source of CO2 (as archaeologists are apt to remind us) and constitute a land use activity that cannot be eliminated or significantly reduced, as other damaging activities (such as mining and oil and gas extraction) might be in a foreseeable future. In addition to the mitigation efforts for land degradation mentioned in the previous section, the IPCC highlights the reduction of food waste, reduced meat consumption (which would presumably correlate with a world in which less land is given over to pastoral uses) the continued genetic engineering of drought resistant and resilient plants, and the diversification of food crops, in combination with a focus on balanced nutrition in production, as a way of getting more food bang for the inevitable carbon buck. Yet because food security is as much a social issue as it is an ecological one, the report’s suggested mitigations fall short of a comprehensive implementation strategy, which must necessarily operate through existing political and social structures and existing markets. In the age of the death spiral of capitalist ideology, its frightening to think that things might have to get worse before there’s a broad consensus for a switch to a better track. So, Viva la revolution.
Reading the IPCC’s report is a little like reading Issac Asimov’s The End of Eternity, in which the scientists of a technologically advanced, time-traveling society reach continually into the past to make systematic tweaks for more optimal outcomes. That is to say–the document both reports on land-climate situation (a dire one) up to this point, but also attempts to predict potential outcomes across multiple scenarios. The goal of this approach is to help policy makers develop a risk-management system to steward society through the best, the worst, and the middle of the road possible futures:
The land-climate system is complex and future changes are uncertain, but methods exist (collectively known as futures analysis) to help decision makers in navigating through this uncertainty. Futures analysis comprises a number of different and widely used methods, such as scenario analysis (Rounsevell and Metzger 2010), envisioning or target setting (Kok et al. 2018), pathways analysis (IPBES 2016; IPCC 2018), and conditional probabilistic futures (Vuuren et al. 2018; Engstrom et al. 2016; Henry et al. 2018)
While the report broadly summarizes the mechanics behind futures analysis and climate-land use interactions (in short: land use affects climate, and climate effects land use. Ta da!) let it be know that this is not the document to read for a layperson-friendly explanation of the science behind it. The report is instead a concise summary of the top issues in climate change and land use, appended by a huge bibliography of must-follow-up-on material, from papers cited on the history of synthetic fertilizer to papers on the effects of large scale land aggregation on food pricing. Thus the IPCC report is best understood as a meta-study on the latest and greatest research on the broadly changing nature of land cover and use as it relates to climate change. In short: It’s a long, dry read packed with comprehensive and critical information. I read it so you don’t have to. You’re welcome.