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Droughts and desertification are some of the most significant environmental challenges facing populations around the world, particularly in developing countries. The United Nations estimates that three-quarters of the world’s population will be impacted by droughts by 2050. In an effort to understand the causes and consequences of droughts, international research teams are investigating these extreme events around the world to implement mitigation strategies, helping to create a sustainable future. Some of the latest research has been shared in the .

Warming oceans change the flow of water on Earth

Intensification of the water cycle has resulted in an acceleration in water movement between land, oceans and the atmosphere. However, rising sea surface temperatures have the potential to alter the world’s water cycle. The degree to which surface warming increases global mean precipitation is measured as hydrological sensitivity. In the , Shipeng Zhang shares a recent study using model simulations and seas surface temperature observations to estimate global hydrological sensitivity. The results showed that tropical regions may experience greater hydrological sensitivity and that the rate of worldwide precipitation can exceed the rate of water vapour formation, eventually leading to drought. Understanding more about the impact of global warming on precipitation is essential for scientists and policymakers so that mitigation actions can be taken to protect food production, energy security and promote economic development. Read more .

On the left is an image of cracked, bare ground created by drought. On the right is a traffic light sign almost covered by floodwaters.

Drought impacts food availability and conflicts  

The availability of water resources is a key trigger for human conflict, particularly when political or socio-economic factors influence decision-making. In the , Martina Sardo explores how water availability has altered crop yields and food security, likely contributing to conflicts across Central America between 1996 and 2016. In this region, the dry season (between July and August) can have severe impacts on agriculture, which is the principal source of income for many rural communities. The research team created simulations of the water cycle across Central America to determine the frequency of drought and its subsequent impact on agriculture. The team found that conflicts were more likely when trade networks between urban and rural areas broke down due to imbalances in food availability resulting from water shortages. Areas experiencing drought therefore more frequently experienced conflict because of social stress associated with reduced food availability. Read more about this research .

A map of Central America showing food availability, plus the locations and dates of community conflicts.

Unprecedented extreme events are not unexpected

Modelling of extreme weather events, such as droughts, principally relies on data about historical occurrences. But researchers question whether only implementing mitigating strategies in areas that have previously experienced disasters is wise, as this may put areas at risk that have had few historical experiences of extreme weather. In the , Erin Coughlan de Perez reports on the risk in two of the world’s major wheat producing regions – Midwest United States and Eastern China. For the US, historical climate simulations revealed that extreme heat that was previously experienced only once in 100 years is now occurring every 6 years on average. In Eastern China, simulations show extreme heat occurs every 16 years, on average. With extreme heat comes an increased likelihood of drought. The research team have identified key vulnerabilities in agricultural practices, specifically targeting wheat growth. By understanding the risks to crops resulting from extreme heat, growers can implement mitigation strategies (such as altering planting schedules or growing heat tolerant varieties) to protect crop yields.  Read more . 

An up close view of wheat in a field.

About the author

Charlotte Bird is the Research Communities Content Manager at PÕ¾ÊÓƵ and is responsible for showcasing the multidisciplinary research published in our journals through commissioning Behind the Paper posts and engaging audiences via the Nature Portfolio Instagram and Twitter accounts.