UNCCD Calls For A Shift From The Current "Age of Plunder" Toward An "Age of Respect" of Biophysical Limits

HAPPY WORLD SOIL DAY!

Roughly half of the world's surface area has been converted to land grazed by domesticated animals, cultivated crops, or production forests resulting in the loss of more than half of the world’s forests. 

Soil health can be defined as “the continued capacity of the soil to function as a vital living ecosystem that sustains plants, animals, and humans.” At present, land degradation and desertification are rampant threats to the sustainability of livelihoods, a phenomenon mostly experienced in drylands, which support over 44% of world food production.

Degraded dryland ecosystems increase vulnerabilities. Photo: Binh Thuan, Thien Anh Huynh/Vietnam/UNEP

Drylands are fragile ecosystems characterized by infertile soils and sparse vegetation cover and where average rainfall is counterbalanced by evapotranspiration. In 2000, the UN Convention to Combat Desertification (UNCCD) estimated drylands to cover 40% of the global land surface. Recent studies (Huang et al., 2015) have shown that this figure will increase to 48% by 2025 and 56% by the end of the century. Such an expansion will further undermine soil's carbon sequestration potential and enhance regional warming. Land degradation and desertification will be exacerbated in drylands located in developing countries ''where 78% of dryland expansion and 50% of the population growth will occur under'' (Huang et al., 2015).

The UNCCD Global Land Outlook report published this year qualifies our current food system as inefficient, highlighting the current patterns of food production, distribution, and consumption as highly unsustainable. It criticizes the current agribusiness model which ''benefits the few at the expense of the many: small-scale farmers, the backbone of food production for millennia, are under immense stress from land degradation, insecure tenure, and a globalized food system that favors concentrated, large-scale, and highly mechanized farms'' (GLO, p.11).

Land-System Change

Basic principles of good husbandry include: respecting land capacity; preserving genetic diversity, conserving soil (quality and quantity); managing rainwater; maintaining plant cover. Today, the aggregated impacts of agricultural transformations are replacing sustainable land use practices and contribute significantly to global environmental changes. Studying these changes requires questioning the sustainability of land-use dynamics, how they might affect changes in climate and global biogeochemistry and vice versa. 

The 9 Planetary Boundaries of Earth System Processes to guide the way humanity governs Earth. Check out all the Control variables for the 9 Earth System Processes

A planetary boundary is a concept created by Earth System scientists from the Stockholm Resilience Center to ''define a safe operating space for human societies to develop and thrive'' (Steffen et al., 2015). The control variables for land-system change include the irreversible and widespread conversion of native biomes, affecting carbon storage and resilience through losses in biodiversity and landscape heterogeneity. The short video below gives an idea of why it is important to identify 'limits' to human activities:

One of the main ways in which the agricultural sector contributes to climate change is deforestation. Methane and nitrous oxide have significantly higher warming potentials compared to carbon dioxide (in a 100-year time horizon) and are the main greenhouse gases from agricultural activities. However, carbon dioxide is the deforestation and forest degradation account for around 20% of global greenhouse gas emissions. 

Source

Forests are globally important in regulating climate and locally important in sustaining communities and supporting biodiversity; however, industrial-scale human activities have altered the physical properties of land surfaces and its interactions with the biosphere and atmosphere. Biomass burning (for land clearing), fertilizers and pesticides, species transfer, plowing, irrigation, drainage, livestock pasturing, amongst others, have impacts that lead to secondary environmental impacts such as biodiversity loss, soil erosion, degradation, albedo alteration (Meyer and Turner, 1994). Environmental feedbacks to land-system change, in turn, require resilient human responses (B.L Turner, 1994).

 Land-cover change in temperate regions

The reflecting power of incoming solar radiation by surfaces (albedo) depends on land cover. Modelling studies estimated that increased surface albedo due to deforestation in temperate regions has most likely exerted a negative radiative forcing, in other words, produced a cooling effect. Bett's research (2000) shows that afforestation efforts to mitigate CO2 concentrations in temperate and boreal regions can actually ''offset the potential carbon sink'' by creating a low surface albedo that exerts a warming influence on climate. Thus it is important to consider the effects of land-cover change and land-use dynamics, ''both of which have strong human controls'' in mitigation targets.

Land-cover change in tropical regions

If the deforestation of the temperate and boreal forests has now broadly stabilized, it is the tropical forests that are being rapidly destroyed. More than 50% of rainforests have been severely degraded or converted mainly for agricultural expansion, accounting for nearly 90% of the total forest loss. The conversion of forests for cattle pasture is the second major contributor to tropical deforestation and is almost entirely concentrated in Latin America (Lovell S. Jarvis, 1986). 

Credit: Nicolle Rager Fuller, NSF