© Alexandra Wey/picture-alliance/KEYSTONE
Animal husbandry must become more sustainable – cows on display in Switzerland.
Climate change has a bearing on land use, which, in turn, has a bearing on the climate. In August, the IPCC published a special report which assesses the interlinkages. For this purpose, 107 scholars from 52 countries, including a majority of developing countries, reviewed 7,000 scientific research papers.
Today, 70 % of the earth’s ice-free land is affected by human action. Only one percent is used for infrastructure, while 12 % is cropland, 37 % pastures and 22 % commercial forests. The remaining 28 % is basically unused land, including virgin forests, various ecosystems as well as deserts and mountain cliffs.
The share of used land keeps growing. From 1961 to 2017, according to the IPCC, food production increased by 240 %. The drivers of this trend were additional land use as well as higher productivity. Ecosystems are shaped by land use – often in a bad way. Fertile soils are being lost, desertification is progressing, and biodiversity is dwindling. Farms are currently using 70 % of the world’s potable water. It is worrisome, moreover, that soils are losing their capacity to store carbon because, next to the oceans, the ground is earth’s most important carbon sink. Non-sustainable land use is thus exacerbating global warming.
Global warming is happening faster above land then above seas. The international community set itself the goal of not letting the global average temperature rise more than 1.5 degrees above the preindustrial level. On land, that has already happened. The global average temperature, by contrast, has only risen half as much.
Climate change means that extreme weather is becoming more frequent and more intense. In many places, the consequences include faster land degradation and desertification. Food security and entire ecosystems are at risk. As the authors point out, what is happening in different world regions varies considerably, but the general trend is that low income countries are affected worst.
The future impacts of global warming do not only depend on how much temperature rises. Population growth, consumption habits, modes of production and innovative technology all matter as well. It is encouraging that the scientists see several options for land-use systems contributing to climate mitigation and adaptation. In many cases, such change would not imply more competition for land. At the same time, it would deliver co-benefits, the experts state.
A core issue is sustainable land use. Management must be geared to the conservation of resources such as soils, water, plants and animals. The ecological services must continue. The report states: “Reducing and reversing land degradation, at scales from individual farms to entire watersheds, can provide cost effective, immediate, and long-term benefits to communities and support several Sustainable Development Goals (SDGs).”
The authors are in favour of sustainable agriculture, less fertiliser use and reduced meat production. They point out that 25 % to 30 % of all food either rots before it is marketed or is thrown away later. Reducing that waste would make a huge difference.
To redirect land use, governments must adopt appropriate policies, the IPCC demands. Relevant issues include ensuring that all farmers have access to markets as well as to the land resources they depend on. Moreover, food prices should reflect not only production costs, but environmental damages as well. The authors leave no doubt: action is needed immediately. That is true in every of all sectors with a bearing on the climate.
IPCC special report climate change and land: