benign

Greenhouses and the environment

July 25, 2024 By EarthWise Leave a Comment

The use of greenhouses around the world has been growing dramatically. A new satellite mapping exercise estimated the total land area covered with permanent greenhouses at 3.2 million acres, which is an area the size of Connecticut. More than half of this is in China, where the growth of greenhouses has been driven by the rapid urbanization of the country and by a more prosperous population increasingly consuming produce like tomatoes, cucumbers, peppers, and eggplants.

The intensive agricultural methods employed within greenhouses can be harmful to local environments because of overtaxing water supplies and by polluting rivers and soils with nutrients, pesticides, and plastic waste. But the effects of vast areas of plastic coverings on local temperatures can be even more dramatic, and often beneficial.

There are so many plastic and glass roofs in many areas that they are reflecting sufficient amounts of solar radiation to cool local temperatures. Greenhouse roofs increase the albedo – the reflectivity – of the land surface typically by a tenth.

All these greenhouses are just the tip of the albedo iceberg. Many farms now temporarily cover crops with reflective plastic sheets. If these coverings are included in the satellite survey, the total reflective area would be about ten times greater – roughly the size of New York State.

A study in Almeria, on the Mediterranean coast of Spain, which grows about 3 million tons of fruit and vegetables annually, determined the cooling effects of greenhouses. Weather stations amid the greenhouses showed an average cooling of 1.3 degrees Fahrenheit compared with the surrounding area.

Greenhouses are an accidental and benign form of climate engineering. The cooling provided by greenhouses is similar to the effect of white roofs in urban areas.

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Could the Global Boom in Greenhouses Help Cool the Planet?

Photo, posted September 6, 2017, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sodium-ion batteries

January 31, 2024 By EarthWise Leave a Comment

The transition away from fossil fuels is driving a rapidly increasing need for batteries. Both electric vehicles and energy storage for the electric grid are enormous consumers of batteries. At present, lithium-ion batteries are almost universally used for these purposes. They have been getting better all the time and cheaper all the time and are likely to be the answer for the foreseeable future. But they are not perfect.

Lithium is only found in a relatively small number of places and mining and extracting it is fairly expensive and environmentally unfriendly. Lithium-ion batteries also frequently contain cobalt, which has its own set of problems. There are also safety issues related to the flammability of lithium-ion batteries.

As a result, there continue to be numerous efforts to identify and develop alternative battery technologies. One of these is sodium-ion batteries, which are similar in many ways to lithium-ion batteries but in which sodium replaces lithium as the cathode material.

Sodium is extremely common – it’s found in ordinary salt – and sodium-ion batteries have a high energy density and are easy to produce. They should have a long lifetime and have a more benign environmental impact than lithium-ion. Many companies and researchers are working on sodium-ion batteries and are making good progress.

A study by Chalmers University in Sweden looked at the potential for sodium-ion batteries and found that the batteries are particularly promising for use in energy storage even in their current state of development and could eventually be used in cars. Whether sodium-ion batteries can be good enough and cheap enough quickly enough to give lithium-ion a run for its money remains to be seen.

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Resource-efficient and climate-friendly with sodium-ion batteries

Photo, posted March 12, 2013, courtesy of Chris Hunkeler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastics and agriculture

November 14, 2023 By EarthWise Leave a Comment

Once celebrated as a symbol of modern innovation, plastic is now both a blessing and a curse of our time. Since the 1950s, more than nine billion tons of plastic have been produced, and 50% of that has been during the past 15 years. Plastic is ubiquitous in every sector, and agriculture is no different.

Modern agriculture is responsible for almost a third of global greenhouse gas emissions and is a major drain on the planet’s resources. Modern agriculture is also inextricably linked to plastic. In fact, more than 13 million tons of plastic are used in agriculture every year. It’s nearly impossible to imagine modern agriculture without plastics.

But according to a new study led by researchers from Rutgers University, plastic use in agriculture must be reduced in order to mitigate pollution, and prevent toxic chemicals from leaching into the soil and adversely affecting human health.

In the study, which was recently published in Nature Communications Earth & Environment, the researchers found that it is essential to adopt a strategic approach to mitigate plastic pollution in agriculture, including responsible usage, reduction, efficient collection, reuse, and the implementation of innovative recycling methods.

According to the researchers, when these sustainable approaches aren’t possible, biodegradable and nontoxic bioplastics should be used. The research team insists that environmentally benign additives should be mandated in order to reduce plastic toxicity.

Plastic pollution is a problem that needs to be addressed in every sector.

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Plastic Use in Agriculture Must be Reduced, According to New Research

How can the use of plastics in agriculture become more sustainable?

Photo, posted November 12, 2022, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio