Global warming may be detrimental to rice, maize and wheat harvest in Europe and North America, concluded a group of scientists from the UK, the US, Australia and North America according to the results of a meta-analysis of crop yield under climate change and adaptation.
The authors state that the global warming of only 2 C may negatively affect the harvests in temperate or tropical regions of the world by as early as 2030.
The research will be included in the Working Group II report of the Intergovernmental Panel on Climate Change (IPCC). This document, which will become a part of the IPCC Fifth Assessment Report, is due to be published at the end of March 2014.
“Due to increased interest in climate change research, the new study was able to create the largest dataset to date on crop responses,” says the scientific work abstract published on the website of Leeds University, UK.
In the study, the researchers combined and compared more than 1,700 published assessments of the response that climate change will have on the yields of rice, maize and wheat, which is more than twice the number of materials that were available to analyze for the previous IPCC Assessment Report.
“Our research shows that crop yields will be negatively affected by climate change much earlier than expected,” said lead author of the study, Professor Andy J. Challinor from the School of Earth and Environment at the University of Leeds.
Earlier on, the scientists who worked at the IPCC Fourth Assessment Report published in 2007 had reported that regions of the world with temperate climate, such as Europe and most of North America, could withstand a global temperature rise of a couple degrees without any noticeable negative effects, and even possibly benefit from a bumper crop.
However, the researchers’ point of view changed after they had analyzed new information.
“[The shift in consensus is] telling us that the impacts of climate change in temperate regions will happen sooner than later,” Andy Challinor explained.
According to him, harvests will become more and more unpredictable and will heavily depend on the weather.
“The impact of climate change on crops will vary both from year to year and from place to place,” the professor added.
Andy Challinor also emphasized that the overall picture will remain negative, and stressed the importance of continuing the research in this regard.
According to the results of the study, the negative impact of climate change will become noticeable in 15-20 years.
“The impact will be greatest in the second half of the century, when decreases of over 25% will become increasingly common,” the abstract says.
This estimate already accounts for minor adaptation techniques used to mitigate the effects of climate change, when the farmers have to adjust crop variety and planting date.
“Later in the century, greater agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations,” the authors of the research concluded.