New Delhi: Unless human beings rapidly alter land use patterns and dietary habits, the world will not be able to avert a climate crisis, the latest report of the UN’s Intergovernmental Panel on Climate Change (IPCC) has warned.
Even more dire is the report’s stress on the fact that such a crisis would happen even if fossil fuel emissions are cut according to terms agreed upon in the Paris climate agreement of 2015, unless our ties with food and land change.
Human activity directly affects over 70% of the global ice-free land surface. Deforestation, agriculture and other land use activities now account for 23% of the total human-caused greenhouse gas emissions. Since 1961, the per capita supply of vegetable oil and meat has more than doubled. About 30% of the total food produced is wasted.
These factors contribute to significant greenhouse gas emissions, the report said.
The global population is using land and freshwater resources at an ‘unprecedented’ rate with agriculture accounting for about 70% of global fresh water use. In addition to increased greenhouse gas emissions, this has led to the loss of natural ecosystems and biodiversity and has speeded up the process of land degradation and desertification which are already exacerbated due to climate change.
The report has also found that the rate of soil erosion is up to 100 times higher than the rate of soil formation on lands that are being tilled and up to 20 times higher on lands that are not being tilled.
This problem becomes particularly acute because climate change causes more land degradation and more land degradation in turn results in more climate change. As land degrades, its ability to absorb carbon dioxide reduces, which in turn fuels climate change.
The IPCC report, approved by members of the UN, focuses on land and is the second in a series of special focus reports of the panel.
The first report, released in October last year, warned that the world is warming faster than was previously thought and that a global temperature rise of 1.5° Celsius is likely between 2030 and 2052.
Unsustainable use of land worsening matters
The latest IPCC report has argued that the rise in global warming as a result of human-caused greenhouse gas emissions is, in part, a result of the unsustainable use of land for agriculture, forestry and livestock rearing.
Loss of forest cover has also contributed to the crisis. Forests act as carbon sinks by absorbing it from the air and reducing the impact of carbon emission on global temperatures.
Increased consumption of meat too has added to the problem. The supply of meat depends on the use of land for livestock grazing and cultivation of animal feed. As more land is cleared for these, deforestation increases.
This, in turn, means that absorption of carbon from the air reduces, leaving it in the atmosphere and adding to global warming. To make matters worse, the animals themselves emit another greenhouse gas – methane.
Consequently, the IPCC has recommended a change in dietary habits. “Balanced diets featuring plant-based foods, such as coarse grains, legumes, fruits and vegetables, and animal-sourced food produced sustainably in low greenhouse gas emission systems, present major opportunities for adaptation to and limiting climate change,” said Debra Roberts, co-chair of the IPCC’s working group two.
Land as an ally
Amidst the gloom, the IPCC has also seen some light in the capacity of land to act as an ally in the fight against climate change. “Sustainable land management can contribute to reducing the negative impacts of multiple stressors, including climate change, on ecosystems and societies,” it said. While land is a source, it is also a sink of greenhouse gases.
But the world’s current land use patterns will have to change for it to stand a chance of staying ‘well below’ 2° Celsius of global warming, as was envisaged in the Paris agreement.
Afforestation, for example, can help combat climate change by absorbing and removing carbon dioxide from the atmosphere. Carbon is stored in tree trunks, roots, branches and leaves. More forests will mean that the earth’s ability to sequester carbon dioxide will increase.
But for this to happen, afforestation would need to take place at a rate faster than deforestation. Current patterns, however, are worrying. The Amazon rainforest – the world’s largest tropical forest – is being cut at an alarming rate. Deforestation in the part of the rainforest contained in Brazil increased 88% between June 2019 and 2018.
Restoration of peatlands is critical as they can sequester carbon for centuries, the report said. It has also argued that increased food productivity, more climate friendly dietary choices and reduction of food wastage can reduce the demand for more land to be used for the purposes of supplying food. Potentially, this could also free up land that can then be used to implement other strategies of combating climate change.
The report sees another benefit in ‘avoiding, reducing and reversing’ desertification as doing this would ‘enhance soil fertility, increase carbon storage in soils and biomass, while benefitting agricultural productivity and food security.’
“There is real potential here through more sustainable land use, reducing over consumption and waste of food, eliminating the clearing and burning of forests, preventing over harvesting of fuelwood, and reducing greenhouse gas emissions, thus helping to address land-related climate change issues,” said Panmao Zhai, co-chair of the IPCC’s working group one.
This potential can be realised only if the world acts now. The more time taken to act, the more carbon will be released into the atmosphere, which in turn will need larger amounts of land to sequester the additional carbon.
Not only that, land may well turn to an adversary from an ally. Increased emissions will lead to ‘irreversible impacts on some ecosystems’ which could in turn mean substantial additional greenhouse gas emissions from those eco systems, thereby accelerating climate change.
The report also makes it clear that acting on sustainable land use alone will not solve the problem. Reducing fossil fuel emissions remains key.