Wetter Here, Drier There: How Climate Change Is Reshaping Water Risk

Md. Jannatul Naeem Jibon
Jun 12
2 min read

Climate change is shifting rainfall patterns worldwide. Nearly 500 million people now live in wetter climates than what was typical in the 20th century—mainly in mid to high latitudes. Meanwhile, over 160 million people, mostly in tropical and subtropical areas, face unusually dry conditions. Beyond just changes in average rainfall, shifts in rainfall timing and river flows are also becoming more noticeable. These changes are beginning to bring serious social impacts and growing risks in both overly wet and overly dry regions.

Some regions are getting wetter, others drier—both above and below the surface

These changes affect not just rainfall, but also soil moisture, river flows, and groundwater. While precipitation plays a key role, so does evaporation, which increases with rising temperatures and is influenced by plant water use. Climate change affects all these processes. Warmer air boosts evaporation and dries out landscapes, though in some places this is balanced by plants drawing less water from the soil due to higher CO₂ levels. And while global warming generally increases rainfall, shifting wind patterns are leaving some areas with less rainfall.

Climate patterns are shifting, and millions are feeling the effects

Today, nearly 500 million people live in climates that are wetter than the 20th-century norm—mostly in mid- and high-latitude regions—while over 160 million face drier conditions, largely in the tropics and subtropics. But it’s not just about averages; when and how rain falls is changing too. Dry spells are getting longer in many areas, especially West Africa, South Asia, and parts of South America—affecting around 600 million people. Meanwhile, about 360 million people, mostly in North America, northern Asia, and parts of South America, now experience shorter dry periods.

Heavy rainfall is on the rise for many

Around 600 million people are experiencing more intense precipitation, compared to just 80 million seeing less. As the world warms, this trend is expected to grow—warmer air holds more moisture, and hotter surfaces fuel stronger storms. River flows are changing too, largely due to shifting rainfall patterns, though human activities like damming and water extraction also play a role. In general, high-latitude regions are seeing more river flow, while mid- and low-latitudes often face declines—though there are many exceptions, and data is limited in some areas.

These climate-driven changes are already affecting society

In some cases, like parts of the U.S., increased rainfall has boosted crop yields. But more often, extreme weather brings serious harm. Heavy and prolonged rainfall leads to flooding, causing deaths, injuries, infrastructure damage, disease outbreaks, school and work disruptions, trauma, and even displacement. Many major floods in recent years were made more likely by climate change, although local factors still play a bigger role in most cases.

Dryer soils have also worsened heatwaves. As landscapes dry out, fire seasons grow longer, fueling record-breaking wildfires around the world. Climate change has also increased the likelihood of major droughts, severely affecting agriculture in many regions.

Overall, rainfall patterns are shifting. Mid- and high-latitudes are getting wetter, while the tropics and subtropics are drying out. Heavy rainfall is becoming more intense, and both wet and dry extremes are already impacting societies worldwide.