The Intergovernmental Panel on Climate Change (IPCC) has just published its latest “Special Report on Climate Change and Land”, prepared by 107 experts from 52 countries and based on 7,000 scientific studies. I4CE, the Institute for Climate Economics, provides you with a summary of the main elements of this document:
The land sector (agriculture, forestry and other land uses) is responsible for 22% of anthropogenic emissions. By causal chain, global warming, by increasing the risks of degradation of permafrost and coastal regions, soil erosion and desertification, could lead to more greenhouse gas (GHG) emissions.
While this sector is partly responsible for climate change[mainly through deforestation], it is also one of the most affected. Food chains, in the first place, are already affected in some regions and may be irreversibly so in the future. Land degradation and desertification as well as extreme events such as droughts or floods that will intensify impact agricultural production and weigh heavily on the food security challenge.
It is therefore necessary to quickly activate all the levers to reduce the impact of the land sector on climate change while reconciling this mitigation issue with the other two fundamental issues of adaptation and food security.
The three main families of levers to reduce anthropogenic emissions from the land sector are:
- Reducing greenhouse gas (GHG) emissions: the main objective here is to reduce methane and nitrous oxide emissions from agriculture by implementing new practices, technologies or systems such as better management of nitrogen fertilization, methanization of animal waste or the development of conservation agriculture.
- Increasing carbon sinks: afforestation, reforestation, intercropping, planting hedges, etc. are all ways of storing additional carbon. But of course, all these solutions must go hand in hand with maintaining the carbon stock already present in the soil and in the above-ground biomass through the preservation of existing forests, peat bogs, grasslands, etc.
- Producing biomass as a substitute for fossil energy or highly carbonaceous materials: this will not reduce emissions from the land sector but will decarbonise other sectors such as the energy or building sector.
If for the first lever and part of the second lever, the sliders must be pushed to the maximum, the right level of biomass production in substitution for fossil fuels as well as the right level of afforestation and reforestation are more complicated to measure since it is necessary to find the right balance in order not to compromise the issue of food security. Indeed, large-scale afforestation, reforestation and bioenergy production increase the risk of conversion of agricultural land and rising food prices.
But the area dedicated to food production is not the only determinant of food security and other parameters must be taken into account:
- Demographics and therefore the number of people to feed: planning for optimal land use depends in part on population forecasts.
- Modify diets with a focus on reducing meat consumption.
- The level of waste: currently, about a third of agricultural production is wasted. Reducing this waste, whether at the production/processing level (improving the cold chain, investing in efficient storage systems, etc.) or at the consumer level, will reduce food demand and thus pressure on the land.
But the technical, technological, organisational and other solutions to be implemented depend on the local context, so local responses are needed. For example, better irrigation can increase production, thus increasing the return of organic matter to the soil and reducing the need for cultivated land, but it can also aggravate drought problems in some regions and increase the risk of desertification.
Finally, it is necessary to plan dynamically the allocation of land and resources, potentially requiring compromises between the various issues (mitigation, adaptation, food security, health, biodiversity, etc.), in consultation with all the sectors concerned (agricultural sectors, sectors
Plus d’informations :
- IPCC special report « Climate Change and Land »
- I4CE Report « Estimating greenhouse gas emissions from food consumption: methods and results»
- I4CE Report «Food policies and climate: a literature review»