Blue Planet Prize Story

It may appear that industry causes more environmental problems than agriculture, but industry has progressively been controlled over the last 40 to 50 years through anti-pollution laws established in many countries. However, compared with industry, agriculture has few controls. Fertilizers and pesticides are used excessively in many countries. About 40% of the land on earth is used for agriculture, and new croplands are continually being created by destroying ecosystems around the world. Thirty percent of all greenhouse gases, which cause global warming, come from agriculture.

Demand for Food Continues to Increase

Although the agricultural impact on the environment is large at present, it is possible that it will be even larger in the future. This is because global demand for food will continue to increase as the world's population continues to grow.
Professor Tilman examined expected increases in gross domestic product (GDP) and how GDP influences dietary choices in nations to predict how much the demand for food would increase in the future. The results were serious for humans. The United Nations (UN) predicts that the global population will increase by 30% from 2010 to 2050. To feed 30% more people, the results of Professor Tilman's research showed that we may need to increase global crop growth by more than 100%.

But why? It is because we need to produce more for other purposes. For example, we need about 2,000 kilocalories a day to live, but high-income nations need to produce more than 8,000 kilocalories per person per day of crops. That's because we have to feed crops to the livestock that we later eat and some crops are wasted. As people become richer, they tend to eat more meat, which requires more cropland and livestock feed.

Yes, there are. For example, by adding the right amount of fertilizer when crops need it, much more food is produced while agricultural groundwater pollution and greenhouse gases are minimized. By growing two different rice varieties in alternative strips, farmers can eliminate serious diseases of rice, which could well eliminate the need for expensive and toxic fungicide. Shifting from monocultures to intercropping with two crops, grown in alternating strips, increases yields 20 to 30% while using less fertilizer. (He states that species diversity is a major determinant of ecosystem productivity and stability.) Professor Tilman believes that it is possible to increase crop yields without creating new cropland, which we call sustainable intensification of agriculture.

Ideas that Changed Society

Professor Tilman's research on the environmental impact of agriculture, especially on the impact of greenhouse gases from agriculture, was highly regarded by the Intergovernmental Panel on Climate Change (IPCC) and cited in its Special Report on Climate Change and Land (SRCCL) published in 2019. It was very meaningful for Professor Tilman because the research was used to help solve environmental problems.

However, he feels that not enough of the lessons learned from this research have been adopted by society. It often takes a significant amount of time for new findings to be adopted by society and for those findings to change our daily lives. But Professor Tilman wants to accelerate the speed of such changes in society.
Are there any good ideas? For example, use of the internet and smartphones has spread quickly. If many people want it or want to do it, it will be quickly accepted by society. We should find a similar way to spread new information quickly in society.

4. Solving Problems of Diet, Health, and Environment
at the Same Time