Climate Change and Land: An IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems

About a quarter of the Earth’s ice-free land area is subject to ‘human-induced degradation’, that is, an adverse land condition caused directly or indirectly by humans that leads to a long-term reduction in, or loss of, the land’s biological productivity, ecological integrity, or value to humans.

Climate change, including an increase in the frequency and intensity of extreme climate events, has adversely impacted food security and terrestrial ecosystems, and contributed to desertification and land degradation in many regions. The report defines desertification as “land degradation in arid, semi-arid, and dry sub-humid areas resulting from many factors, including climatic variations and human activities.”

The expansion of areas under agriculture and forestry (including those for commercial production) have supported food availability for the world’s growing population. These changes (which vary vastly by region) have contributed globally to increasing GHG emissions, the loss of forests, savannahs, grasslands and wetlands, and declining biodiversity.

People currently use a quarter to a third of the land’s potential ‘net primary production’ (NPP) for food, feed, fibre, timber and energy. (NPP is the amount of carbon accumulated through photosynthesis minus the amount lost by plant respiration, which would prevail in the absence of land use.)

Changes in land conditions (such as heat-related events) and heavy precipitation events can significantly modify the likelihood, intensity and duration of many extreme climate events. They can also affect temperature and rainfall in regions hundreds of kilometres away.

Asia and Africa are projected to have the highest number of people vulnerable to increased desertification. North America, South America, the Mediterranean, southern Africa and Central Asia may be increasingly affected by wildfire. The tropics and subtropics are projected to be most vulnerable to crop yield decline.

The report says that access to cleaner energy sources and technologies can help to mitigate climate change and combat desertification and forest degradation. This can have socioeconomic and health benefits, especially for women and children.

Insecure land tenure affects the ability of people to make changes to land that can help with climate change adaptation and mitigation. Land policies (including the recognition of customary tenure, community mapping, redistribution, decentralisation, co-management, and regulation of rental markets) can help provide people with security and give them flexibility in their responses to climate change.

Public health policies to improve nutrition (such as increasing the diversity of food in public procurement), health insurance, financial incentives, and awareness-raising campaigns can potentially influence food demand, reduce healthcare costs, and contribute to lower GHG emissions. Influencing the demand for food by promoting diets based on public health guidelines can enable more sustainable land management.

Agricultural practices based on indigenous and local knowledge can contribute to overcoming the challenges of climate change, food security, biodiversity conservation, desertification and land degradation. Such practices can be adopted through coordination between businesses, producers, consumers, land managers, policymakers and indigenous peoples.

The land and food sectors around the world face particular challenges of ‘institutional fragmentation’ and narrowly focussed policies. Coordination with other sectors, such as public health, transportation, environment, water, energy and infrastructure can benefit them all at the same time.

The report says that policies which reduce food loss and waste, influence dietary choices, improve access to markets, secure land tenure, and factor environmental costs into food, among others, could help make land use more sustainable. Such policies could also enhance food security, lower emissions, reduce land degradation, desertification and poverty as well as contribute to climate change adaptation and mitigation.

PARI Library's health archive project is part of an initiative supported by the Azim Premji University to develop a free-access repository of health-related reports relevant to rural India.