These NASA images show the staggering impact of drought

Images from space show water levels falling dramatically at Lake Mead, the biggest reservoir in the United States.

NASA has been recording water levels at Lake Mead for 22 years through its Earth Observatory.

Water levels at the lake are now at their lowest since April 1937, just after the reservoir was built, the US space agency says.

Lake Mead is a reservoir created to store water – on the Colorado River, bordering the states of Arizona and Nevada in the US.

It supplies water for drinking and irrigation to millions of people across seven states, tribal lands, and northern Mexico, NASA says. Lake Mead is a “critical source of water” for 25 million people, says The New York Times.

The Hoover Dam, which created Lake Mead, was built between 1931 and 1936. In 1937, the reservoir was still being filled for the first time.

Lake Mead’s water level was just 27% full on 18 July 2022.

The falling water level shows up as a phenomenon called the “bathtub ring”, NASA explains. This is where mineralized areas of Lake Mead’s shore that were previously under water appear as light-coloured fringes around the shoreline.

This is clearly visible in three images from 2000, 2021 and 2022 that NASA displays side by side.

At full capacity, Lake Mead would hold 9.3 trillion gallons – 36 trillion litres – of water. “The lake last approached full capacity in the summers of 1983 and 1999,” NASA says.

NASA’s images are a “stark illustration of climate change”, the space agency says.

Climate change is heating the planet and is linked to warmer and drier weather in the US. According to the United States Environmental Protection Agency, average temperatures across the US have been rising faster since the 1970s, and extreme weather events such as heatwaves are becoming more common.

In May, drought of varying levels affected more than 60% of the US, data shows.

Low water levels in Lake Mead come as long-term drought in the US West may be at its worst in 1,200 years, The New York Times has reported.

Some level of drought is currently affecting 74% of nine Western states and there is “extreme or exceptional drought” across more than a third of the area, says NASA.

More than three-quarters of the world could face drought by 2050, the United Nations (UN) warns in a recent report, Drought in Numbers 2022.

The frequency and length of droughts has already increased 29% since 2000, warns the UN’s Convention to Combat Desertification (UNCCD), which compiled the report.

“When more than 2.3 billion people already face water stress, this is a huge problem,” says Ibrahim Thiaw, UNCCD executive secretary.

Droughts have killed 650,000 people between 1970 and 2019 – making them the world’s deadliest natural disaster – and directly affect an estimated 55 million people a year globally, the UN report reveals.

Its report lists restoring forests, regenerating grasslands and controlling erosion as some of the ways to combat desertification and drought.

Practical interventions that countries have taken include the creation of a drought vulnerability map for Australia to show where work is most needed to mitigate drought.

A project in California is focused on replenishing groundwater – water under the earth’s surface. This “directly benefits” communities and agricultural land in the region, UNCCD says.

In Africa, drought intervention projects include an early warning system for small-scale farmers and a project to distribute 2,000 communal water tanks.

The World Economic Forum’s Global Shapers Community is working to engage young people with the issues facing the planet and encourage them to invest their time in driving dialogue, action and change. It currently has a network of over 10,000 young people in 150 countries.

The Community identifies climate change as a top priority and in its first 10 years of operation has directly impacted almost 140,000 people around the world through myriad environmental projects run on a volunteer basis.