Climate crisis: Simply reducing pollution will not save planet as agriculture is also revealed to be major culprit
Reducing carbon emissions from cars or factories will not be enough to tackle the climate crisis, warns new report on climate change, which calls for a complete overhaul in the way land is managed and food is produced.
The reason: land use and abuse is a significant contributor to the climate crisis, with agriculture, forestry, and other types of land use accounting for 23% of human greenhouse gas emissions.
At the same time, natural land processes absorb carbon dioxide equivalent to almost a third of carbon dioxide emissions from fossil fuels and industry, says the UN’s Intergovernmental Panel on Climate Change (IPCC) report, which was released on Thursday.
Agriculture, forestry and other land use activities accounted for around 13% of carbon dioxide, 44% of methane, and 82% of nitrous oxide emissions from human activities globally during 2007-2016, representing 23% of the total global greenhouse emissions.
“If emissions associated with pre- and post-production activities in the global food system are included, the emissions are estimated to be 21-37% of all greenhouse gas emissions,” says the report on climate change and land, which was prepared by 107 experts from 52 countries.
Changes in land conditions, either from land-use or climate change, affect global and regional climate.
Since the pre-industrial period, the land surface air temperature has risen nearly twice as much (1.53°C) as the global mean surface (land and ocean) temperature (which increased by 0.87°C).
This additional warming, say the researchers, has resulted in an increased frequency, intensity, and duration of heat-related events, including heatwaves in most land regions.
“Both global warming and urbanization (a result of land use change) can enhance warming in cities and their surroundings. Climate change, including increases in frequency and intensity of extremes, has adversely impacted food security and terrestrial ecosystems as well as contributed to desertification and land degradation in many regions,” they state.
The report adds that better land management can contribute to tackling climate change.
According to the researchers, the target of keeping global warming to well below 2ºC—if not 1ºC—can be achieved only by reducing greenhouse gas emissions from all sectors, including land and food.
The Paris Agreement on climate change mitigation aims at keeping the global average temperature to well below 2°C above pre-industrial levels, with an ambition of limiting warming to 1.5°C.
“The level of risk posed by climate change depends both on the level of warming and on how population, consumption, production, technological development, and land management patterns evolve. Pathways with higher demand for food, feed, and water, more resource-intensive consumption and production, and more limited technological improvements in agriculture yields result in higher risks from water scarcity in drylands, land degradation, and food insecurity,” says the report.
People currently use land for food, feed, fibre, timber and energy, and human use directly affects more than 70% of the land globally, says the report.
Expansion of areas under agriculture and forestry, including commercial production, and enhanced agriculture and forestry productivity have contributed to increasing net greenhouse gas emissions, loss of natural ecosystems (forests, savannahs, natural grasslands and wetlands) and declining biodiversity.
The researchers state that emissions from agricultural production are projected to increase, driven by population and income growth and changes in consumption patterns.
The scientists explain that when land is degraded, it becomes less productive, restricting what can be grown and reducing the soil’s ability to absorb carbon.
This exacerbates climate change, while climate change, in turn, exacerbates land degradation in many multiple ways.
“About a quarter of the earth’s ice-free land area is subject to human-induced degradation. Soil erosion from agricultural fields is estimated to be currently 10 to 20 times (no tillage) to more than 100 times (conventional tillage) higher than the soil formation rate. Climate change exacerbates land degradation, particularly in low-lying coastal areas, river deltas, drylands and in permafrost areas (high confidence). Over the period 1961-2013, the annual area of drylands in drought has increased, on average by slightly more than 1% per year, with large inter-annual variability. In 2015, about 500 (380-620) million people lived within areas which experienced desertification between the 1980s and 2000s,” says the report.
“The highest numbers of people affected are in South and East Asia, the Sahara region including North Africa, and the Middle East including the Arabian peninsula. Other dryland regions have also experienced desertification. People living in already degraded or desertified areas are increasingly negatively affected by climate change,” it adds.
The scientists state that sustainable land management, including sustainable forest management, can prevent and reduce land degradation, maintain land productivity, and sometimes reverse the adverse impacts of climate change on land degradation.
The report also calls for major improvements in the way food is produced and managed.
The researchers say that about one-third of the food produced is lost or wasted. The reasons behind food loss and waste differ substantially between developed and developing countries, as well as between regions. Reducing this loss and waste would reduce greenhouse gas emissions and improve food security, says the team.
“Reduction of food loss and waste can lower greenhouse gas emissions and contribute to adaptation through a reduction in the land area needed for food production. During 2010-2016, global food loss and waste contributed 8-10% of total greenhouse gas emissions. Currently, 25-30% of the total food produced is lost or wasted,” says the report.
The report says that, according to available data, per capita supply of vegetable oils and meat has more than doubled and the supply of food calories per capita has increased by about one-third. Changes in consumption patterns have contributed to about two billion adults now being overweight or obese, even as an estimated 821 million people are still undernourished.
The researchers say that some dietary choices require more land and water, and cause more emissions of heat-trapping gases than others. They recommend a balanced diet, with more focus on plant-based foods. “Balanced diets, featuring plant-based foods, such as those based on coarse grains, legumes, fruits and vegetables, nuts and seeds, and animal-sourced food produced in resilient, sustainable and low greenhouse gas emission systems, present major opportunities for adaptation and mitigation while generating significant co-benefits in terms of human health,” they recommend.
The report says policies that operate across the food system, including those that reduce food loss and waste and influence dietary choices, enable more sustainable land-use management, enhanced food security, and low emissions trajectories.
“The adoption of sustainable land management and poverty eradication can be enabled by improving access to markets, securing land tenure, factoring environmental costs into food, making payments for ecosystem services, and enhancing local and community collective action,” says the report.