Agriculture's Greenhouse Gas Problem Needs a Mindful Reset
The Hidden Climate Story Behind Your Breakfast Plate
Agricultural practices are the source of over a quarter of greenhouse gas emissions. How we grow our food and fibre is a significant source of atmospheric pollution—a challenging but necessary admission.
Every time you sit down to eat, you're participating in one of humanity's most remarkable achievements and its biggest environmental challenges.
That perfectly ripened avocado on your toast, the milk in your coffee, even the slice of bread holding it all together—each has a hidden climate story that might surprise you.
I've spent decades studying how humans interact with nature, and here's something that still amazes me. Over a quarter of all greenhouse gas emissions come from growing our food, not from cars, planes, or factories but from feeding ourselves.
As an ecologist, I find this fascinating.
As someone who enjoys eating (and assumes you do too), I find it somewhat terrifying and where mindful scepticism becomes invaluable.
In this issue of Become a Mindful Sceptic, we'll cut through the overwhelming statistics and contradictory headlines to understand what's happening in our food system. You'll gain practical insights to inform your food choices, understand the challenges facing modern agriculture, and see why this isn't just a climate change issue but an ecological one.
You'll end up with a clearer understanding of:
Why agriculture's climate impact is both more straightforward and more complex than you might think
How your food choices connect to global emission patterns
What realistic solutions look like (hint: they don't involve giving up eating)
How to think more critically about agricultural sustainability claims
Ready to take a mindful sceptic's journey through one of humanity's most pressing challenges?
Let’s start with some inconvenient facts.
Understanding greenhouse gas emissions from agriculture
Over the 12,000 years since we figured out how to rear livestock and grow crops, agricultural practices produced around a third of cumulative greenhouse gas emissions from human activity.
Most of this is from land clearing, fossil fuel use, fertilisers, and cattle belching.
Most of us are unaware of this reality and encouraged to be so by political and business leaders who dare not do anything about it.
It would be convenient to blame farmers and food suppliers for greenhouse gas emissions, but we shouldn’t.
Before apportioning blame, think a little about the process that brings the Thai beef salad to your lunchtime delight…
Emissions from land clearing happen because land without native trees, shrubs, grasses and herbs supports less biomass with a more rapid turnover of the biomass it does have compared to natural vegetation. Greenhouse gases are also released from soil when exposed to the elements as rates of soil organic matter (SOM) decomposition tend to increase without the protection of vegetation cover.
Agricultural practices themselves are also emission sources. Fossil fuels drive tractors and a dizzying array of farm machinery. There are over 4 million tractors on farms and ranches in the United States alone.
Industrial processes use energy and fossil fuels as raw materials to make inorganic fertilisers. The International Fertilizer Association reports that the Haber-Bosch process made roughly 150 million metric tons of ammonia in 2021. When in the soil, fertilisers can release nitrous oxide (N2O), which has a GWP (global warming potential) 273 times that of CO2 for a 100-year timescale.
Crop residue burning also releases carbon. For example, about 2 million farmers in northwest India burn an estimated 23 million tons of rice residues annually. In the cities of northwest India, particulate air pollution can exceed the safe daily threshold limit by more than five times, demonstrating in real time that this is an emission problem.
Then there are methane emissions, a greenhouse gas with a global warming potential (GWP) 27 times greater than carbon dioxide, emitted from flooded soils under rice cultivation, enteric fermentation in the digestive systems of livestock, and the decomposition of manure and crop residues under wet conditions.
According to the UN Food and Agriculture Organisation (FAO), the league table for the most significant GHG emissions from agricultural practices once the land is cleared is
enteric fermentation (40%),
manure left on pasture (16%),
synthetic fertiliser (16%),
paddy rice (10%),
manure management (7%)
burning of savannahs (5%)
Here is a summary of the volume of these GHG emissions relative to the total in 2014 from a recent global research review using data from the Intergovernmental Panel on Climate Change.
Even without the fossil fuel burning that powers the farm machinery, the land clearing, and the industries that produce the inputs, agriculture accounts for over 20% of global emissions from human activities thanks to methane and nitrous oxide, upwards of 10 Gt CO2e per year.
The challenging but necessary admission that we must make, preferably without judgment, is that agriculture is a significant source of greenhouse gas emissions.
Ongoing source of greenhouse gas emissions
South Asia is home to just shy of 2 billion people, one-quarter of all the people on the planet.
Population growth and climate effects are expected to increase food demand in the region by 40% by 2050. There are two massive challenges to meeting this demand.
First, 94% of the land suitable for farming is already under production. This means there is minimal scope for expansion of the agricultural output by area. There is little new land to put into production.
The second challenge is that 58% of agricultural areas are already under stress from water shortage, extreme heat stress, and poor soil health. The production area is not in great shape. Conventional cultivation practices with exhaustive tillage and removal of crop residues by burning or for other uses result in nutrient and carbon losses and the air pollution problem.
There is only one obvious solution to this imperative to grow enough food—a net production increase of over 1% per annum for the next 30 years—and that is to add inputs.
The conventional wisdom is that farmers will have to make soils more productive and efficient by adding fertilisers, pesticides, herbicides, and extra energy for tillage and water management.
In the current mechanisation and industrial production system, these inputs come predominantly from fossil fuels.
It is a wicked problem for the farmer, the politician, and the environmental advocate. Farmers will be under immense pressure to make ends meet. Politicians will want to keep all this under wraps or risk destabilising food systems, while the ‘Just stop oil’ warriors will still want smashed avocado on toast for breakfast.
Cost of inputs, availability and the emission consequences of inputs in production systems that produce methane and nitrous oxide will combine to make everyone unhappy.
The medium-term answer for everyone is a return to intensive small-scale production that uses the soil's natural capacity to renew and circulate nutrients on the farm. It is an ecological challenge, not a climate one.
Why are agricultural emissions about ecology and not climate change?
Emissions of greenhouse gases from fossil fuels are a human construct.
We found the fuel and burnt it in our machines. We use those machines in agriculture and the industrial processes that generate agricultural inputs to deliver food production from land use change.
Then, we use energy to transport, store, process, retail and cook food. The food supply chain is a massive energy sink.
And we could stop there.
Many industrial countries did just that and kept agriculture from any emission targets they had set to combat climate change.
Greenhouse gas emissions are a consequence of agricultural practices and the food system that comes after the food is grown. And those practices that produce crops and livestock products are about changing the way ecology works. Agriculture alters nature to channel as much biomass production from the land as possible into the parts of plants and animals that humans like to eat.
External energy sources subsidise modern agriculture to augment production and make the ecology faster and more efficient for the products we desire, but it doesn’t have to be.
There is enough capacity and capability in nature to produce enough food without the inputs but not without considerable changes to consumer expectations, consumption, behaviours and farming practices.
Being a mindful sceptic on a greenhouse gas emissions reset
Agriculture is responsible for a third of historic and ongoing greenhouse gas emissions.
Given that the demand for food is growing, an increase in emissions from agriculture is likely. We could lay blame or ignore this truth when attempting to set total emissions reduction targets, as many countries have done.
But as we always say, the 22 trillion calories a day challenge to feed people has to be met somehow or risk the ugly consequences of failure.
A mindful sceptic might suggest a reset.
Let’s look again at agriculture as an ecological process and retrofit or replace the current food production systems with ones closer to nature.
This means that many people will eat less and differently. It will mean more farmers and much shorter supply chains. This means that farms recycle nutrients and do more with fewer inputs. This will mean lower energy use, some forestry, and other changes to agricultural land.
And it will be a wild ride.
Mindful Momentum
The Local Farmer Connection
Visit a local farm or farmers' market with three prepared questions about their energy use, soil management, and input requirements. Many farmers love sharing their knowledge. Compare what you learn with this article's data.
The contrast between industrial agriculture statistics and local farming practices can be eye-opening, plus you'll gain first-hand insight into the challenges and solutions we discussed.
If this sounds a little too intrusive, try a more personal action…
The Meal Story Challenge
Track five meals from plate to source, writing down everything you know about how each ingredient reached you. Note what you don't know (there will be lots!).
Research one unknown element each day. Where was the grain in your bread grown? How did those tomatoes get to you in winter? What powered the journey?
This exercise reveals the hidden energy pathways in our food system and trains your sceptical thinking about supply chains.
Key Points
Agricultural practices contribute over a quarter of global greenhouse gas emissions through land clearing, fossil fuel use in farm machinery, fertilizer production, and livestock emissions. The cumulative impact of over 12,000 years of agriculture accounts for roughly one-third of human emissions, making food production a major driver of climate change.
The current agricultural system faces severe constraints in meeting growing food demand, particularly in regions like South Asia, where 94% of arable land is already farmed and 58% of agricultural areas face environmental stress. This creates pressure to intensify production through increased use of fossil fuel-dependent inputs, potentially driving emissions even higher.
Rather than viewing agricultural emissions as a climate change issue, a mindful sceptic recognises this as fundamentally an ecological challenge. While fossil fuel emissions are a human construct, agricultural emissions stem from how we've altered natural systems to redirect biomass production for human consumption. This suggests solutions should focus on working with ecological processes rather than just emissions reduction.
Moving toward sustainable food production requires a systemic reset that embraces small-scale intensive farming, works with natural nutrient cycles, shortens supply chains, and shifts consumer expectations. While this transition presents significant challenges, there is sufficient ecological capacity to produce adequate food with fewer inputs if agricultural practices and food systems are appropriately redesigned.
Curiosity Corner
This issue of the newsletter is all about…
From the tractor in the field to the avocado on your toast, agriculture's greenhouse gas emissions tell a story of how we've transformed natural systems to feed ourselves—and why the solution lies in understanding ecology, not just counting carbon.
Here are five more illuminating questions that emerge from this newsletter—the kind that might change how we think about agriculture and emissions:
1. What if we stopped treating agricultural emissions as a climate problem and started seeing them as signals from disrupted ecological systems? This reframes the entire discussion. Rather than asking how to reduce emissions, we're asking what those emissions tell us about our relationship with natural systems.
2. Why do we measure agricultural success by yield per hectare rather than ecological stability? I love this question because it challenges our fundamental metrics. It's like judging a marathon runner solely by their speed in the first mile - we might be missing the more important story.
3. How did traditional farmers feed their families from 2-3 acres without fossil fuel inputs, and what can that teach us about modern food security? This cuts to the heart of our assumptions about scale and efficiency. When my students hear this question, it often stops them in their tracks.
4. What would our food systems look like if we designed them around soil health rather than quarterly profits? This question emerged from watching the contrast between small-scale organic farmers and industrial agriculture. It helps us imagine different possibilities.
5. Instead of asking how to reduce agricultural emissions, shouldn't we be asking how to rebuild agricultural ecosystems?
In the next issue
Think You Can Count All The Species In Your Backyard? Think Again.
Coming next week, we explore why even experts can't tell you exactly how many species live on Earth and what this startling gap in our knowledge means for the future of conservation.
I'll share stories from four decades in ecology about the hidden diversity right under our noses and why understanding how nature works matters more than memorising Latin names.