25 June 2019

Climate change is already affecting food production worldwide


Researchers from the University of Copenhagen, University of Minnesota and the University of Oxford have shown that crops around the world are already affected by climate change. This means a decrease in yield in almost half of the countries where food production is already precarious. The results are published in PLOSONE.

Photo: Drought in Ethiopia. Source: Wikimedia Commons

The world’s 10 most important crops; barley, cassava, corn, palm oil, rapeseed, rice, sorghum, soybeans, sugar cane and wheat account for 83 percent of the crops produced worldwide. Scientists have long expected that yields will fall in the future due to climate change, but new figures show that the future has already arrived and climate change is already affection the production of these important energy sources.

Earlier research has combined climate scenarios and crop models to project what the yields will be for a limited number of crops. But the area is very complex, which is why the researchers in the new study have used statistical and computational models as well as satellite data to assess the consequences of climate change. 

The recently published data elaborates on statistical data from 1974 to 2008. During this period, the global surface temperature increased between 0.16°C to 0.18°C per decade. The study finds that some crops, such as soybeans, have benefited from climate change, while other crops, like oil palms, suffer greatly from the changing climate.

The results show that climate change has the most negative effect in Europe, South Africa and Australia, a generally more positive effect in Latin America, while the effects in Asia, North America and Central America are more mixed.

The results are alarming

27 out of 53 countries with a “Hunger index” of serious, alarming or extremely alarming are experiencing a reduction in their food yield as a result of climate change. Sub-Saharan Africa, for example, has experienced a reduction in the yield of maize of 0.14 tons per ha / year. This corresponds to a decrease of 2.3 million tons of maize each year for the whole region and results in an average annual reduction in available kilocalories on 4pct. from 1974 to 2008.

In Europe, we also find that our yields are adversely affected by climate change. It affects crops such as wheat, barley, corn and rapeseed. In Denmark, however, there has been a slight increase in yield of 0.26 tons pr. ha/year. But nevertheless, Europe is suffering from negative consequences of climate change in the agricultural sector. This has already resulted in a decrease in wheat production of 8.7 pct. in Western Europe and 2.1 pct. in Northern Europe.

Alexander Prishchepov, Associate Professor at the Department of Geosciences and Natural Resource Management at the University of Copenhagen, has contributed to the research with data supply, expert assistance for the analysis and interpretation of the results. Han explains:

“The results are relevant to the major food companies, international food trade and the countries where they operate, as well as to citizens all over the world. The results are also relevant to those who work professionally with the UN World Goals to eliminate hunger and combat climate change. Political efforts should address adapting cultivation practices in the different countries so that they are better equipped to withstand climate change. As scientists, we must get better at understanding the relationship between temperatures, precipitation changes and their impact on crops”.

Impact of mean climate change on crop yield (tons/ha/year).

Read the article in PLOSONEhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0217148