The climate crises humanity is causing as a result of our wasteful burning of fossil fuels are happening in the face of mounting evidence that that burning was very, very bad for the Earth. Some of the issues are now officially coming even sooner than expected. If we want to have the hope that we can even reduce these problems, we have to change our habits, preferably yesterday.
While burning fossil fuels is a big part of the problem, food production is also a primary driver of climate change. It is responsible for about 25 to 30 percent of greenhouse gas emissions. In addition, it also depletes groundwater, converts carbonaceous forests and jungle into cropland, and dumps excess nitrogen and phosphorus into soil, water and air. In business-as-usual scenarios, these effects are likely to at least double by 2050, as the global population is expected to increase by about a third and the global population’s income will also increase – all those new and new rich(er) people are likely to want to eat and eat well.
At that point, the environmental impacts of food production will “be outside the planetary boundaries that define a safe business space for humanity.”
There is no quick fix. To curb these effects, a combination of different measures is needed. So says a recent report and analysis in Nature. But these measures are extremely ambitious, and even if they could be implemented, it seems that we are still using too much groundwater (into which we are going to pour nitrogen and phosphorus).
The researchers looked at a few options for changes we could make, and assessed their effects on each of the environmental parameters listed above: greenhouse gas emissions, water use, land use, nitrogen application, and phosphorus application. These include dietary changes, reductions in food waste and improvements in technology. Each of these changes was examined in degrees – for example, they examined reducing meat consumption to three servings per week, as well as one serving per week. (This is relevant because animals are responsible for about 75 percent of greenhouse gas emissions attributed to agriculture.) They also examined the relative effects of cutting food waste by half and three-quarters (estimated one-third — one-third! produced food is currently lost or wasted).
The hypothetical improvements in technology, they judged, would narrow the gap between achievable and achieved returns by 75 or 90 percent. These improvements make the most of every acre and improve fertilization and irrigation efficiency to maximize nitrogen, phosphorus and water use. They only looked at technological solutions “that are considered realistic or achievable, or have been set as targets” – so no carbon sequestration in the soil, extensive use of nitrogen-fixing bacteria or additional GMO technology.
They found that we could reduce greenhouse gas emissions to amounts that would keep us outside the planetary boundary range if everyone ate not only less meat, but also less, period: “lower consumption of meat, staple crops and sugar, and an overall lower energy intake in line with a healthy body weight.” We also need to cut food waste by at least half, and these measures combined with moderate technological innovations could keep us within the average limits of water use and cropland use.
But to stay below the maximum value of the limit range for nitrogen and phosphorus application would not only require eating less, but also reducing food waste by three quarters, “ambitious technological improvements” and “a more optimistic socio-economic development trajectory that promotes a lower population and higher income growth than is currently expected.”
Of course, food production doesn’t just affect the environment; the environment also affects food production. This analysis did not take into account what climate change is like and will impact on things like crop yields and freshwater availability. It also recognized, but failed to take into account, the political and economic realities that investing in efforts to curb climate change caused by factors other than agriculture could limit the resources available to implement the changes outlined here.
Another caveat is that making these changes requires investment in public infrastructure and the establishment and enforcement of regulations, and these measures can be almost as difficult to achieve as eating less meat. The report suggests that one way to mitigate the effects of a growing population is to ensure that women have information about and access to contraception.
Eating à la Michael Pollan – eating, not too much, especially plants – is not only better for your body, it is also better for the planet. Who knows, he may also be right about LSD.
Nature2018. DOI: 10.1038/s41586-018-0594-0 (About DOIs).