Is the world running out of freshwater?

More than half of the world’s population faces water scarcity for at least one month a year.

Safe water is a basic human right and essential to our health, whether we use it for drinking, food production or hygiene. But it is also a limited resource.

Only about 3% of the earth’s water is fresh watermost of which are in frozen glaciers, ice caps or deep underground.

As climate change accelerate the frequency of extreme weather events and higher temperatures, our fresh water supply is shrinking and the risks to human health bigger.

This is one of many reasons why the world is running out of water. From an increasing population requiring more food and energy, to expanded use in agriculture and industry—stress on water is increasing.

Water scarcity can cause human displacement and poverty. Contaminated water can transmit disease such as diarrhoea, cholera and polio. And for millions of women and children, the physical strain of walk up to 12 kilometers a day to collect water endanger their health.

How does the global water shortage affect people’s health?

In California, devastating droughts and rising temperatures have affected the water cycle. This extreme weather conditions led to increased evaporation and changing rainfall patterns. The US state experienced its driest three years on record between 2019 and 2022.

While violent storms previously depleted reservoirs filled in 2023, groundwater reserves remain critically low. Today, nearly one million Californians are affected by failing water systems.

Most cities have made investments to diversify their water supply and expand conservation efforts, but smaller rural communities that rely on wells are increasingly vulnerable. Many Californians rely on drinking water that may contain chemical contaminants. Drought can further increase these contaminants, while fire damage to the well equipment can add toxic chemicals to the water.

The changing water is already harming people’s health. For example, after the 2018 Campfire in Butte County—California’s most destructive wildfire in history—chemical contamination of the drinking water system resulted in health risks and restrictions on water use. In a survey of more than 200 households after the fire54% self-reported that at least one member in their household experienced anxiety, stress or depression related to security safe water and pollution issues.

Nine thousand miles from the California crisis, Kenyans face even greater climate-related water shortages and the serious health risks associated with it.

Kenya contributes less than 0.1 percent of global greenhouse gas emissions annually but like many low-emission countries, it is disproportionately affected by the effects of the climate crisis.

Widespread drought has led to extreme food insecurity [PDF 34.8MB]. Ngawosa Eregai, a community health worker in Turkana County, says: “The biggest challenge we have is lack of water.”

Four or five people have to use their hands to dig deep holes in the ground where the rivers used to be to get to water. “We drink this water because we don’t have a choice,” says Ngawasa. “We trust that it will not be harmful.”

For Esther Elaar, who fetches water every day and carries it for her family to use, the four-hour walk weighs on her physical health. “My whole body hurts,” she says. “I usually carry 20 liters of water at a time because the water point is far.”

The long and hot walk to water affects expectant women like Esther. Their babies die before they are born.

“While I’m carrying water, I feel the baby moving in my womb,” says Esther. “Many women have miscarried in this area while going to look for water.”

What can be done to prevent freshwater decline?

Ester’s story is just one of millions.

The groundwater in Germany which provides almost 70% of the country’s drinking water, is declining. Iran’s retreat Lake Urmia becomes saltier as it shrinks and affect the water, soil and clean air available to local villagers. And prolonged droughts in Peru damaged agriculture and access to clean water in indigenous communities.

The climate crisis is changing water on Earth and the health impacts reach far and wide.

With just 2°C of warming, up to three billion people are expected to experience chronic water scarcity. Current policies around the world are projected to lead to around 2.7°C of warming above pre-industrial levels. But we have the knowledge and tools to prevent this from happening.

This involves implementing strategies such as conserving water and restoring freshwater ecosystems such as wetlands. To achieve this, we need tremendous political action, greater financial investment and a whole-of-society approach.

At Wellcome, we work with the people most affected by climate change to support critical research, tools and resources. If we act together now against climate change, we can protect our water and our health.