Troubled land: a call for sustainable land use and rapid climate action
28 August 2019
Claire Fyson, Quentin Lejeune, Carl-Friedrich Schleussner
The IPCC’s latest report explores the complex interactions between climate change, land degradation and food security. It provides a stark reminder that climate change places the life support systems that land provides at risk. All countries have a stake in the future of the land, but with receding coastlines, encroaching land degradation and declining food supply stability, the small island developing states and least developed countries are among the most vulnerable. For these nations in particular, there is no sustainable future without sustainable land use combined with rapid climate action.
What does the current level of climate action mean for the land? The IPCC looked at the risks of warming on six key land system components: food, livelihoods, the value of land, human health, ecosystem health and infrastructure. If we stay on our current path to 3°C of warming by the end of the century, we can expect high to very high risks for all of these components, resulting from impacts such as tropical crop yield decline, food supply instabilities, and dryland water scarcity. Only limiting warming to 1.5°C can effectively limit these risks.
But there’s another side to the story. How we use the land – for agriculture, forestry and other uses – will not only be affected by climate change, but it also contributes to the problem, generating a substantial portion (almost a quarter) of global greenhouse gas emissions. Policy measures and actions in the land sector can help to address climate change by reducing these emissions and contributing to adaptation. The good news is that the IPCC also found that such actions can come with social, ecological, economic and development co-benefits, including poverty eradication and more resilient livelihoods for the most vulnerable, as well as many synergies with combating land degradation and desertification.
Ahead of the UN summit in September, the IPCC has provided a call to action for governments to ramp up climate action in their national determined contributions, to bring the world on track to achieve the 1.5°C limit of the Paris Agreement. The steps for doing so are clear: rapid emissions reductions are needed in all sectors, including from land-based activities, and the more sustainable the development path we follow, the greater our ability to reduce emissions and at the same time sustain essential land-based systems will be.
Adverse impacts of climate change on land
The first section of the newly released IPCC report contains many worrying observations. It clearly states that climate change is already harming wildlife and contributing to desertification, land degradation and food insecurity in many regions. For example, climate change has already directly affected pastoral systems in Africa, as well as food security in the drylands of African and high-mountain Asian regions. Increasingly frequent and intense extreme rainfall and heat events are amplifying ongoing land degradation, and sea level rise is intensifying coastal erosion, increasing land use pressure in SIDS and low-lying coastal regions. These risks are set to increase with warming.
Particularly concerning are the risks that could affectfood suppliesat greater levels of warming, especially in tropical and sub-tropical regions. The stability of food supply will decline as the number and intensity of extreme events that disrupt food chains grow; by around 2-3°C of warming such risks could be very high. There will also be reductions in tropical crop yields and crop suitability, with already moderate levels of risk today set to climb to high levels by 2°C of warming. Additionally, higher atmospheric CO2 concentrations can reduce the nutritional quality of crops (for example, lower levels of protein, zinc and iron). The projected impacts of climate change are set to cause food prices to climb, hitting the most vulnerable people the hardest.
Some parts of the world may even become uninhabitable under the effects of climate change. Extreme weather and slow-onset events can drive more people to migrate, both within and across borders, and can even contribute to the drivers of conflict. For tropical islands, the combined effects of sea level rise and more intense tropical cyclones will cause coastal erosion and land degradation, threatening lives and livelihoods. Such risks can surpass adaptation limits, meaning that land degradation is unavoidable and, in some cases, land may disappear altogether.
Land-based measures for mitigation, adaptation, food security and addressing land degradation
On the brighter side of things, the report’s second section shows that land-based solutions to address climate mitigation, adaptation, land degradation and food security exist and are readily available. Most solutions can simultaneously address many, or even all, of these challenges, and at the same time contribute to sustainable development. In fact, many options are already being implemented or are available for deployment.
The global food system will have to play a major role in achieving a sustainable land future. Solutions will need to address both food production (such as improved crop and livestock management) and food consumption. Balanced dietspresent opportunitiesfor both adaptation and mitigation, while generating significant co-benefits in terms of human health and freeing up land for other uses. Tackling food loss and waste, which currently makes up 25-30% of current food production, will also play an important role in reducing emissions and freeing up land. Solutions include technical options for improving harvesting, storage, packaging and transport, as well as retailer and consumer education.
Ecosystem degradation including of coastal wetlands as well as deforestation and forest degradation need to be urgently reduced. Ecosystem restoration as well as reforestation and afforestation can offer very effective opportunities for land-based mitigation and adaptation if implemented sustainably.
Most mitigation pathways include substantial deployment of bioenergy and Bioenergy coupled with Carbon Capture and Storage (BECCS). If deployed at very large scales these could result in considerable negative impacts for land degradation, adaptation and food security. However, if deployed at smaller scales and according to best practices they could have co-benefits across these challenges. The IPCC’s previous special report on Global Warming of 1.5°C (SR1.5) already looked at how to limit the need for large-scale carbon dioxide removal options such as BECCS, and found that 1.5°C pathways with reduced dependency on such technologies rely on even more rapid and far-reaching transitions across all sectors, as well as on behavioural and lifestyle changes.
With the life support systems provided by the land at risk from the escalating impacts of climate change, the IPCC has presented a clear case for changing how we use the land to make these systems more resilient, while at the same time reducing emissions and contributing to sustainable development. But its most important message is that we need to act fast if we want to sustain these support systems in the future, and mitigation action in the land sector alone is not enough.
Any delay in slowing warming will make the land more vulnerable, rendering land-based mitigation options less effective and potentially contributing to further warming. Furthermore, delayed action to reduce emissions will mean larger scales of land-based mitigation will be needed to limit global warming to the same temperature limit, raising the risk of adverse effects of land degradation, adaptation and food security. These findings add further weight to the argument that the use of land-based mitigation to offset emissions from burning fossil fuels should be strictly limited to only the small portion of emissions that are too difficult to mitigate, such as those arising from some agricultural systems or transportation means.
Limiting warming to 1.5°C through rapid economy-wide mitigation action will reduce the negative impacts of climate change on land ecosystems, food security and the economy, among others, while bringing co-benefits for sustainable development. If combined with efforts to restore degraded land and ecosystems and develop sustainable land management systems, long-term damage to food production and land-based ecosystems can be avoided. The opportunities for producing a sustainable land future are there, but action must unfold now to seize them so that the rapidly closing window of opportunity is not missed.