Land use and its link to climate change
Earlier this month, the Intergovernmental Panel on Climate Change (IPCC) published a special report on the relationship between climate change and humanity’s use – or, more accurately, misuse – of our planet’s land.
At over 1,300 pages, and with a title that runs to 26 words, the report is not exactly light reading. But its findings present a stark warning that couldn’t be more clear: land is critical to the survival of our societies and the global economy, yet we are using it in a way that is causing unprecedented and potentially irreversible damage.
The IPCC report brought together over 100 experts from 52 countries. They were tasked with summarising the most reliable science on the current state of Earth’s land resources, the challenges that existing patterns of land use present and the possible benefits of more sustainable practices.
The report estimates that human use directly affects more than 70% of Earth’s global, ice-free land surface. Land for grazing is the largest contributor to this, followed by managed forests and cropland.
The risks associated with these activities include a loss of biodiversity; increased land degradation and desertification (where the ecological richness and productivity of land declines over time); and less resilient food systems. In turn, these risks undermine food security, impact local and regional ecosystems, and hamper efforts to tackle climate change.
As the report highlights, land use and climate change are inextricably linked: land can act as a sink for greenhouse gases, through carbon stored in trees or soil, for example. But land use can also be a significant source of emissions: the report found that agriculture, forestry and other uses of land were responsible for 23% of anthropogenic greenhouse gas emissions between 2007 and 2016.
At the same time, climate change is amplifying the pressures that humanity is already placing on land. Increases in average temperatures affect growing seasons and can impact certain species or entire ecosystems. Shifting weather patterns and an increase in extreme weather events linked to climate change can also alter rainfall patterns, increase the risk of drought, cause widespread crop failures, or make wildfires more likely – all of which undermine the stability of land-based ecosystems.
Addressing multiple challenges
Given the scale of these challenges, is it possible to move to an approach that protects land-based ecosystems for future generations and ensures we avoid the worst effects of climate change?
The IPCC offers some hope, noting: “The land that we are already using could feed the world in a changing climate and provide biomass for renewable energy.” However, they leave no room for complacency as success “require[s] early, far-reaching action across several fronts”.
Action is needed to simultaneously address climate change, desertification, land degradation and food security. As these are very closely interlinked, it’s possible that an intervention could help to address multiple challenges or alternatively could involve trade-offs between them.
Moving to sustainable land use
In total, 40 possible responses were evaluated in the IPCC report, broadly categorised into those that rely on land management (eg increased food productivity, improved forest management, and increased soil organic carbon content); those that rely on value chain management (eg dietary change, reduced food waste, and enhanced urban food systems); and those that rely on risk management (eg disaster risk management).
According to the report, most of these response options could be implemented without competing for available land and 17 of them deliver co-benefits or result in no adverse side effects across the UN’s sustainable development goals. These include reducing post-harvest losses, sustainable sourcing, improving energy use in food systems and diversifying livelihoods.
Many of these measures are already being implemented, but the window of opportunity is rapidly narrowing. It’s clear that we need a step change in global ambition and action. The sooner this occurs, the greater our chance of avoiding systemic shocks to our economy, society and the environment.