1992

Globally, freshwater lakes and reservoirs hold 87% of the planet’s liquid freshwater, making them a valuable resource for both people and wildlife. Despite their value, the long-term trends and changes to water levels of lakes have been largely unknown – until now.

According to a new assessment recently published in the journal Science, more than half of the largest lakes around the world are losing water. Using satellite observations and climate data, the research team created a technique to measure changes in water levels in nearly 2,000 of the world’s biggest lakes and reservoirs, representing 95% of the total lake water storage on Earth.

The results are staggering. According to the findings, 53% of Earth’s largest lakes and reservoirs now store significantly less water than they did in 1992. The total amount of water lost is estimated to be 144.5 cubic miles, which is equivalent to the volume of 17 Lake Meads (the largest reservoir in the U.S.).

Unsurprisingly, climate warming and human consumption were the main drivers of water loss from lakes, whereas sedimentation — the buildup of debris — was the biggest driver of water loss in reservoirs. Roughly one-quarter of the world’s population – two billion people – live in the basin of a drying lake, indicating the urgent need for sustainable water resources management.

But the news is not entirely bleak. According to the research team, the new method of tracking lake water storage trends can give water managers and communities insight into how to better protect this critical resource.

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Satellites reveal widespread decline in global lake water storage

Photo, posted February 10, 2010, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

In 1979, an American naturalist named Thomas Hallberg visiting a small town in Oaxaca, Mexico was amazed to find a type of local maize – or corn – that grew nearly 20 feet high in poor-quality soil even though the local farmers did not use any fertilizer.

The unique corn plant had aerial roots that grew a mucous-like gel just before harvest season. It seemed totally implausible, but the plant seemed to be fixing its own nitrogen: extracting it from the air and somehow making it useful to the plant.

In 1992, Hallberg returned with a group of Mexican scientists and collected samples to study in his lab. His research showed that the maize indeed received nitrogen from the air through its aerial roots. It took over 20 years to figure out what was going on in the plants. It turns out that bacteria that thrive in the low-oxygen environment of the maize’s mucus pulls nitrogen from the air and feeds it to the plant.

Scientists will probably spend years figuring out if a commercial application of this indigenous maize is viable. It isn’t guaranteed that the self-fertilizing trait of the plant can be bred into a commercial crop. But if it can, the payoff would be huge. Farmers spend more than $3 billion a year on corn fertilizer in the US alone.

A vexing problem is who should reap the financial benefits of the maize. The isolated village where the plant is grown has already signed an agreement to share in any such benefits. But there are other Oaxacan villages that also grow the plant.

Mexico’s wonder plant is likely to be caught up in the growing issue of biopiracy, which is the exploitation of indigenous knowledge and biological resources without permission.

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Indigenous Maize: Who Owns the Rights to Mexico’s ‘Wonder’ Plant?

Photo credit: ALLEN VAN DEYNZE/UC DAVIS

Earth Wise is a production of WAMC Northeast Public Radio.

Large Lakes In Decline | Earth Wise

Globally, freshwater lakes and reservoirs hold 87% of the planet’s liquid freshwater, making them a valuable resource for both people and wildlife. Despite their value, the long-term trends and changes to water levels of lakes have been largely unknown – until now.

Web Links

Mexico’s Wonder Plant

In 1979, an American naturalist named Thomas Hallberg visiting a small town in Oaxaca, Mexico was amazed to find a type of local maize – or corn – that grew nearly 20 feet high in poor-quality soil even though the local farmers did not use any fertilizer.

Web Links