Irrigation and fresh water

Did you know that 70% of fresh water extraction is for irrigation, mostly for agriculture? Or that this accounts for 90% of global water usage? This covers a large amount of land, higher in certain areas than others. Obviously, there are consequences of this practice.

McDermid and colleagues (2023) examined the impacts of irrigation, both positive and negative, on climate change. While there were some positive impacts, there are a lot of negatives that need to be recognized and addressed. Some of the main impacts the researchers identified included:

• Irrigation can create local cooling and can facilitate some carbon storage. However, it can also increase humidity and encourage the release of greenhouse gases like methane from specific crops.

• It depletes local freshwater supplies, especially groundwater which can contribute to drought and affect water available for both human uses and natural systems. It can also increase run-off and contamination of water bodies by things like fertilizers.

Obviously we require agriculture, but we are creating risks for current and future food production by not addressing these risks now. A systems approach is clearly necessary. Changing crops and technologies, reducing food waste, and adopting practices like cover crops and rewilding will all be necessary to improve food security globally while reducing negative impacts.

Understanding the risks, as McDermid and colleagues have outlined is a step in the right direction, but now what are we going to do about it?