How agriculture is exacerbating global warming

With the rapid rise in global population, the need to feed billions has placed tremendous pressure on agriculture. Millions of hectares of forests have been cut in South America, Asia and Africa to accommodate the swift expansion of farmlands. Local governments and multinational food companies are collaborating to enhance the farm productivity. Over the past couple of decades, enormous efforts have been made by policymakers to enhance investments in agricultural infrastructure.

The results are there for everyone to see. Global production of primary crop commodities reached 9.5 billion mt in 2021, up 54% since 2000, while meat production grew by 53% and milk production by 58%, according to the latest data from the UN Food and Agriculture Organization.

The growth in agricultural output has comfortably outpaced the rise in global population. Between 2000 and 2021, agricultural production growth at 54% had been faster than the population growth at 29%, the FAO said. This was made possible by the intensification in farming activities -- with an increased use of irrigation, pesticides and fertilizers and cropland expansion -- and enhanced production technologies, including improved farming practices and growing high-yield crops.

Despite the speed at which agricultural output is growing, the food security challenge will only become more difficult. According to the World Bank, the world will need to produce about 70% more food to feed an estimated 9 billion people by 2050. With the agricultural commodity prices surging amid ever-rising demand, just imagine the pressure the farming sector and forests will be bearing in feeding the world in the coming years.

Global warming

When we think about global warming and climate change, our thoughts immediately veer toward the manufacturing and transportation sectors. When we think of air pollution, we imagine cars, trucks and fossil fuel guzzling factories. Farmers as polluters are the last thing on our mind.

But things have changed, and dramatically so. Small-scale crop and animal farming communities are being replaced by big multinational agro-business companies. Undoubtedly, this transformation has brought efficiency and economies-of-scale to agriculture. But it has also made farming one of the biggest polluters in the world.

According to the latest report released April 2023 by the Intergovernmental Panel on Climate Change, agriculture, forestry and other land use account for 22% of global greenhouse emissions, making this sector one of the leaders in triggering global warming.

Key greenhouse gases emitted by the farming sector are carbon dioxide, methane and nitrous oxide, according to US Environmental Protection Agency. Carbon dioxide is emitted through deforestation, land clearing for agriculture and soil degradation, while methane is produced through almost all agricultural activities, waste mismanagement in farms, energy usage and biomass burning. For nitrous oxide emissions, fertilizer usage is a primary source.

To be clear, greenhouse gases per se are not harmful. In fact, GHGs occur naturally and are essential to the survival of humans and millions of other living things by keeping some of the sun's warmth from reflecting into space and making Earth livable, a UN report said. But after more than a century and a half of industrialization, deforestation and large-scale farming, quantities of greenhouse gases in the atmosphere have risen to record levels not seen in three million years, the UN said.

As populations, economies and standards of living rise, so does the cumulative level of GHG emissions. It is the excess of greenhouse gases that is exacerbating global warming and inducing climate change.

One of the biggest polluters

Apart from emitting the greenhouse gases, farms have also become notorious waste producers in the 21st century.

It has been estimated that a single large animal farm can produce more waste than a big city.

A farming operation with 800,000 pigs could produce over 1.6 million mt of waste a year, which is one and a half times more than the annual sanitary waste produced by the city of Philadelphia, Pennsylvania, according to Centers for Disease Control and Prevention report. It is estimated that livestock animals in the US produce somewhere between three and 20 times more manure annually than people in the country -- that's as much as 1.2 billion-1.37 billion mt of waste.

Nature striking back

Agriculture's role in changing climate conditions is not a one-way affair. Ironically, farmers have been among the victims of the effects of climate change in recent years. The agriculture sector is highly vulnerable to global warming-induced floods, droughts, hurricanes and wildfires, among others.

The Asian Development Bank reported that between 1961 and 2021, climate change reduced global agricultural yield by 21%. In the same time period, food systems represented a third of total GHG emissions and were a major contributor to biodiversity loss, the ADB said.

From Australia to Canada, wildfires have become a regular occurrence, posing major risks to farmlands, grasslands and rangelands. Temperature and precipitation changes will also very likely expand the occurrence and range of insects, weeds and diseases. According to the EPA, some of threats to agriculture could also be permanent, including soil erosion, groundwater depletion, agricultural land losses, saltwater intrusion and water contamination.

The way forward

There is a consensus among various global organizations that it is not too late to reverse the impact of climate change. And for the farming sector to do its bit in saving the world, sustainable agriculture is the way forward.

Feeding a growing population without overexploiting resources may be addressed through the adoption of long-term sustainable production techniques, the Organization for Economic Cooperation and Development said. The agricultural sector assumes a key role in meeting the sustainable development goals to ensure nutritious and healthy food access, create circular agricultural systems and reduce waste in the supply chain, it said.

A few examples under sustainable agriculture include restricting the over-application of fertilizers, improving pasture quality to increase animal productivity, re-evaluating breeding practices and enhancing manure management.

But according to global think tanks, the biggest challenge will be to entice millions of farmers across the world to uniformly adopt sustainable agricultural practices as soon as possible. This is where the governments will have to be firm in their climate commitments.

Monitoring and regulating the agricultural greenhouse emissions and putting greater emphasis on accountability could go a long way towards averting the global warming catastrophe, because it's not a matter of if but when the climate crisis becomes truly irreversible.