ISLAMABAD: A new scientific report has revealed that seven of the nine planetary boundaries have been negatively impacted by unsustainable land use as land degradation is undermining the Earth’s capacity to sustain humanity.

The report, “Stepping back from the precipice: Transforming land management to stay within planetary boundaries” released on Monday, draws on roughly 350 sources to examine land degradation and opportunities to act from a planetary boundaries perspective.

Alarmingly, six boundaries have already been breached to date, and two more are close to their thresholds: ocean acidification and the concentration of aerosols in the atmosphere.

Only stratospheric ozone — the object of a 1989 treaty to reduce ozone-depleting chemicals — is firmly within its “safe operating space”, warned the report.

The report was submitted to the 16th session of the Conference of the Parties of the United Nations Convention to Combat Desertification (UNCCD) taking place in Riyadh from Dec 2 to 13.

Seven planetary boundaries negatively impacted by unsustainable land use

The planetary boundaries define nine critical thresholds essential for maintaining the Earth’s stability. How humanity uses or abuses land directly impacts seven of these, including climate change, species loss and ecosystem viability, freshwater systems, and the circulation of naturally occurring elements nitrogen and phosphorus. Change in the land use is also a planetary boundary.

Until recently, land ecosystems absorbed nearly one-third of human-caused CO2 pollution, even as those emissions increased by half.

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Over the last decade, however, deforestation and climate change have reduced by 20 per cent the capacity of trees and soil to absorb excess CO2.

Deforestation, urbanisation and unsustainable farming, however, are causing global land degradation at an unprecedented scale, threatening not only different Earth system components but human survival itself.

Moreover, the deterioration of forests and soils undermines the Earth’s capacity to cope with the climate and biodiversity crises, which in turn accelerate land degradation in a vicious, downward cycle of impacts.

Conventional agriculture is the leading culprit of land degradation, contributing to deforestation, soil erosion and pollution.

Unsustainable irrigation practices de­­plete freshwater resources, while excessive use of nitrogen- and phosphorus-based fertilisers destabilise ecosystems, the report said.

Degraded soils lower crop yields and nutritional quality, directly impacting the livelihoods of vulnerable populations. Secondary effects include greater dependency on chemical inputs and increased land conversion for farming.

The infamous Dust Bowl of the 1930s resulted from large-scale land-use cha­nges and inadequate soil conservation.

Land degradation hotspots today stem from intensive agricultural production and high irrigation demands, particularly in dry regions such as South Asia, northern China, the US High Plains, California, and the Mediterranean.

Published in Dawn, December 4th, 2024