Properly managing land and water resources as the global climate changes will be crucial for sustaining agriculture in the future. For example, we will need reliable information on how climate change will affect water availability around the world so that we can effectively adapt to conditions like drought over the next few decades.
Pete Falloon and Richard Betts of the Met Office Hadley Centre focused their study on how future climate change will affect agriculture in the north and south of Europe. The researchers say that the gap between the two regions in terms of water availability will widen as the planet warms. Today, water is more plentiful in northern Europe than in the south. As a consequence, agriculture is generally more productive in the north too. This situation will become more pronounced.
Warming will result in crop suitability zones moving northwards and farmers will likely produce more in these regions compared with the south, where there might be declined productivity. Although water resources will become even more plentiful in the north, earlier snow melt in some parts of northern Europe could cause earlier spring water runoff, leading to water shortages in the summer. Some scientists also believe that both northern and southern Europe could experience an increase in extreme rainfall events and drought, so additional risks to agriculture might come about through increased flood hazards over the entire continent.
"Temperatures are likely to rise throughout Europe so it is mainly future rainfall disparities that will drive differences between regions," Falloon told environmentalresearchweb. "We need to understand and quantify what future risks are and develop ways to cope with these changes."
Overall, increased temperatures will probably have a positive impact on northern Europe and crops will be safer compared with those in the south, where they will be much more vulnerable as the effects of heat are felt. This, coupled with a reduced water supply and increased demand for water for irrigation, as well as greater flood and drought risks, means that farmers will need to plan ahead more carefully in southern regions. For example, if a farmer knows that there is a 50% chance of severe drought in the near future, he or she might decide to plant half conventional crops and half drought-tolerant ones, explained Falloon.
Another important result to come out of the study is that scientists need to consider the wider implications of decisions concerning how we manage water and land. For example, what will increasing crop irrigation mean for global water resources in a region? And how could plans to introduce different crops affect carbon and water balances in the longer term?
The Met Office team is currently involved in a UK Defra coordination project called Integrating Water and Agricultural Management (IWAM) led by Kit Macleod at North Wyke Research. This project hopes to bring together research in this area for policymakers.
"Our work was really aimed at synthesising current findings in the field, with a particular focus on how important interactions between different sectors – such as agriculture and water – and management decisions like adaptive measures and mitigation policies are," said Falloon. "Until now, there have been relatively few studies that include all relevant factors and how they interact, so there is an urgent need to do this."
The work was reported in Science of the Total Environment.