Small farms are key to preventing climate change.

Some of those worst affected by climate change are small farms (those working on land under two hectares). There are around 475 million small farms around the world, cultivating around 12 per cent of the world’s farmed land. Those in the tropics and poorer agricultural communities will be particularly affected by climate change.

However, many of these small farms are increasingly using innovative ways to reduce greenhouse gas emissions and adapt to climate change. They are the true pioneers of climate-smart agriculture, using practices that maintain productivity while decreasing emissions. They are also producing a range of other benefits such as poverty alleviation, better nutrition and biodiversity conservation.

Sustainable but healthy yields

In the 20th century, farmers boosted yields by intensifying production: using more water, land, energy, synthetic pesticides and fertilisers. This model tended to assume that you couldn’t have high yields as well as environmental protection. Now, we understand that this is a false choice, and that sustainable intensification – producing healthy yields and higher incomes while building ecosystems on and around the farm – is possible. And it looks like small farms are leading the way in implementing such sustainable intensification around the world.

There are three steps towards sustainable intensification. These are increased efficiency (doing more with less), substitution (replacing ineffective or harmful products) and redesign (changing the whole farm to be more sustainable). These steps are not necessarily mutually exclusive.

A group of emperor penguins face a crack in the sea ice, near McMurdo Station, Antarctica

Floods destroyed eight bridges and ruined crops such as wheat, maize and peas in the Karimabad valley in northern Pakistan, a mountainous region with many glaciers. In many parts of the world, glaciers have been in retreat, creating dangerously large lakes that can cause devastating flooding when the banks break. Climate change can also increase rainfall in some areas, while bringing drought to others.

Smoke – filled with the carbon that is driving climate change – drifts across a field in Colombia.

Amid a flood in Islampur, Jamalpur, Bangladesh, a woman on a raft searches for somewhere dry to take shelter. Bangladesh is one of the most vulnerable places in the world to sea level rise, which is expected to make tens of millions of people homeless by 2050.

For example, rice plants are typically planted close together in flooded nurseries. But they can also be grown in nutrient-rich nurseries that aren’t flooded – something that saves around 40 per cent of the water used compared to conventional production methods. However, the system is about more than simple resource efficiency – it actually involves a fundamental redesign of the whole system of rice production.

Substitution involves replacing less efficient or harmful inputs such as synthetic pesticides, which can be harmful for wildlife, with better alternatives. You can also replace old crop varieties with new ones that can withstand sudden changes, or which need less water – important for climate resilience. New varieties may also be able to help reduce agricultural emissions. For example, plants with greater root mass could help sequester an estimated 50 to 100 tonnes of carbon per hectare.

Radical approaches

Radical redesign of farms involves techniques such as conservation agriculture – practices that minimise the disruption of the soil’s structure and biodiversity. Integrated pest management, which involves strategies to deal with pests without posing risks to the environment, and agroforestry, using trees in agriculture, are also good examples. A recent assessment estimated that around 163 million farms worldwide (29 per cent of the global total) practice some form of redesign.

The evidence shows that these methods are already helping small farms achieve healthy yields while delivering a range of other benefits, including carbon sequestration, using less energy and synthetic inputs and climate resilience.