Monthly Archives: March 2017

11 percent of disappearing groundwater used to grow internationally traded food

11 percent of disappearing groundwater used to grow internationally traded food

Wheat, rice, sugar, cotton and maize are among the essential internationally traded crops in the global economy. To produce these crops many countries rely on irrigated agriculture that accounts for about 70 percent of global freshwater withdrawals, according to the United Nations Water program. One freshwater source is underground aquifers, some of which replenish so slowly that they are essentially a non-renewable resource.

A new study by researchers at the University College London and NASA’s Goddard Institute of Space Studies in New York City shows that 11 percent of the global non-renewable groundwater drawn up for irrigation goes to produce crops that are then traded on the international market. Additionally, two-thirds of the exported crops that depend on non-renewable groundwater are produced in Pakistan (29 percent), the United States (27 percent), and India (12 percent).

“It’s not just individual countries that experience groundwater depletion, but also their trade partners,” said lead author Carole Dalin of the University College London. “When people consume certain imported foods, they should be aware that they can have an impact on the environment elsewhere.” The results were published March 30 in Nature.

Dalin and her colleagues used trade data on countries’ agricultural commodities from the United Nations Food and Agriculture Organization. They then combined it with a global hydrologic model — validated with ground information and NASA satellite data — to trace the sources of water used to produce 26 specific crop classes from their country of origin to their final destination. Their analysis is the first to determine which specific crops come from groundwater reservoirs that won’t renew on human time-scales and where they are consumed.

“Say I’m in Japan, and I’m importing corn from the United States,” said co-author Michael Puma of NASA’s Goddard Institute for Space Studies and Columbia University in New York City. “It’s important from Japan’s perspective to know whether that corn is being produced with a sustainable source of water, because you can imagine in the long term if groundwater declines too much, the United States will have difficulty producing that crop.”

Globally, 18 percent of all crops grown are traded internationally. The remaining 82 percent stays in country for the domestic market. However, the amounts of various exported crops produced using unsustainable groundwater rose significantly between 2000 and 2010. India, for example, saw its exports of groundwater-depleting crops double in that period, while Pakistan’s rose by 70 percent and the United States’ rose by 57 percent.

Countries that export and import these crops may be at risk in the future of losing the crops, and their profits, produced with non-renewable groundwater. Importers may need to find alternative sources, possibly at a higher cost.

Major importers of crops raised with non-renewable groundwater include the United States, Iran, Mexico, Japan, Saudi Arabia, Canada, Bangladesh, the United Kingdom, Iraq, and China, which went from a net exporter in 2000 to a net importer in 2010. Countries on both lists often export different commodities than they import.

Aquifers form when water accumulates in the ground over time, sometimes over hundreds or thousands of years. Non-renewable aquifers are those that do not accumulate rainfall fast enough to replace what is drawn out to the surface, either naturally to lakes and rivers or in this case by people via pumping. Once that groundwater is depleted, it will effectively be gone for good on the scale of a human life-time, and will no longer be available for relief during crises such as droughts, Dalin explained.

Drawdowns in aquifers worldwide have been observed over the last fifteen years by NASA’s Gravity Recovery and Climate Experiment (GRACE), a pair of satellites that detect changes in Earth’s gravity field to see the movement of masses such as ice sheets and, in this case, underground water.

“What’s innovative about this study is it connects groundwater depletion estimates with country level data,” said hydrologist Matt Rodell at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in the study. More research needs to be done which considers population growth, changing diets, climate change, the implementation of irrigation technology and policy changes to understand when these aquifers may begin to run dry, he said.

The absolute amount of water in many of these aquifers is difficult to quantify, though experts in many regions are already looking at better methods to determine how much water remains and how long it may last, Dalin said. Now and in the future, decision makers and local farmers will need to decide on a strategy for using this non-renewable water that balances the needs of short-term production versus long-term sustainability, she said.

(Why?)
Published at Wed, 29 Mar 2017 18:09:32 +0000

Gardening Tips and Tricks






Gardening Tips and Tricks Gardening Tips and Tricks – Gardening is one of the most popular hobbies in the world. In addition to relaxation, many people also use gardening as a source of food. However, gardening can get a bit frustrating if you are having trouble growing your plants or are consistently battling pests. Whether… Continue Reading

Forests fight global warming in ways more important than previously understood

Forests fight global warming in ways more important than previously understood






Forests fight global warming in ways more important than previously understood [unable to retrieve full-text content] Trees impact climate by regulating the exchange of water and energy between Earth’s surface and the atmosphere, an important influence that should be considered as policymakers contemplate efforts to conserve forested land, said the authors of an international study.Published… Continue Reading

The Top 10 Gardening Tools Everyone Needs






Years ago, gardening tools were built to last and it was not uncommon for a good spade, to cost a week’s wages. As they were an expensive commodity, these gardening tools had to be made to withstand the test of time and were often passed down through generations. You find many of them still being… Continue Reading

What To Look For In Your Container Gardening Soil






Container gardening soil is essential in a thriving vegetable garden or any other kind of cultivation endeavor. The soil is where the plant’s roots get sustenance to thrive and succeed. Gardening soil needs a lot of things to be instrumental to the success of vegetables and plants. The right kind of container gardening soil is… Continue Reading

Farming becoming riskier under climate change






Farming becoming riskier under climate change Scientists the world over are working to predict how climate change will affect our planet. It is an extremely complex puzzle with many moving parts, but a few patterns have been consistent, including the prediction that farming as we know it will become more difficult. Scientists infer the impact… Continue Reading

Organic Gardening and Farming: The Benefits






Organic Gardening And Farming: The Benefits Organic gardening and farming is becoming incredibly popular, and is quickly spreading around the world. The problem is, we all want to do what we can to help the environment and protect the world that we live in, and we are just now realizing how much organic gardening can… Continue Reading

Pollination mystery unlocked by bee researchers






Pollination mystery unlocked by bee researchers Bees latch on to similarly-sized nectarless flowers to unpick pollen — like keys fitting into locks, University of Stirling scientists have discovered. Research, published in Ecology and Evolution, shows the right size of bee is needed to properly pollinate a flower. The insect fits tightly with the flower’s anthers,… Continue Reading

A Brief History of Gardening






Gardening fundamentally splits into two halves; gardening for food (or farming) and gardening for aesthetic pleasure. It’s the history of the pleasurable side of gardening that we’re looking into in today’s article. While gardening for food goes back before records began with some estimates dating it’s inception to approximately 10,000 years ago, gardening for its… Continue Reading