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Planting Rocks To Capture Carbon | Earth Wise

September 8, 2023 By EarthWise Leave a Comment

Getting humanity to stop dumping carbon dioxide into the atmosphere continues to be very challenging regardless of how increasingly apparent the need to do so becomes. For this reason, climate change mitigation strategies increasingly include interventions in the form of removing carbon dioxide that is already there. There are a variety of ways to draw carbon dioxide out of the atmosphere, but they face a host of technological, economic, and even environmental difficulties.

A new study at Yale University evaluated a type of climate intervention called enhanced rock weathering. Rock weathering is a natural chemical process by which certain minerals absorb carbon dioxide over time. Enhanced rock weathering is simply speeding up weathering such so it can have beneficial results soon enough to make a difference.

The study explored the potential of applying crushed basalt, which is a fast-weathering rock that forms when lava cools, to agricultural fields around the world. Basically, the idea is for farmers to mix the crushed rocks into their fields. There is no real downside to doing this. In fact, adding crushed basalt to fields rejuvenates depleted soils and helps counter ocean acidification.

The study simulated the results of enhanced rock weathering on 1,000 agricultural sites around the world. Over a 75-year period, these sites would remove 64 billion tons of carbon dioxide from the atmosphere. This is roughly the amount climate scientists believe is needed to take out of the atmosphere.

Enhanced rock weathering has been used on a small scale on farms around the world. Perhaps it is time to ramp up its use.

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‘Planting’ rocks in farms, along with emissions reductions, could help meet key IPCC carbon removal goal

Photo, posted January 14, 2023, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Scourge Of Salt | Earth Wise

June 10, 2022 By EarthWise Leave a Comment

Rising seas are increasing saltwater intrusion on land and rising temperatures are causing greater evaporation. The result is mounting levels of salt in waters and in soils.

Rising sea levels cause salty ocean water to push further into river deltas. There is already a surge in saltiness across all inhabited continents. Seawater works its way further upstream when dams hold back water. Pumps that remove fresh water from underground sources for irrigation and drinking supplies add to the problem. In dry regions, irrigation systems delivering water to crops increasingly bring salt onto fields.

People add to the problem by pouring saline drainage water from mines into rivers and by using salt to de-ice roads in the winter.

A modeling study pinpointed hotspots for climate change-induced salinization in numerous locations including the U.S. Southwest, wide areas of Australia, Mexico, South Africa, Brazil, central India, northern China, and more.

Some ecosystems are adapted to saline environments but major alterations in the balance between saline and fresh water is creating growing problems for ecosystems, lake fisheries, crop growing, and even human health.

The damage caused by salt is likely to be so severe that salinization will become a major cause of environmental refugees when the land they live on can no longer sustain them.

Salt will be a growing threat to the world’s food supplies, especially where farmers depend on artificial irrigation. About a third of the world’s food is grown in irrigated fields, and a fifth of those fields are deemed to already be salt-contaminated. Ultimately, only a halt to climate change will be capable of combatting the scourge of salt.

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Salt Scourge: The Dual Threat of Warming and Rising Salinity

Photo, posted June 3, 2017, courtesy of Jason Jacobs via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harnessing The Smell Of Fear | Earth Wise

September 28, 2021 By EarthWise Leave a Comment

Plant-eating insects present a major problem for farmers and home gardeners. Aphids, for example, are a highly destructive pest to many crops. Their large numbers and ability to transmit plant pathogens make them a persistent problem for growers.

Pesticides are chemical substances that are commonly used to prevent, destroy, repel or mitigate pests. They include insecticides for insects, rodenticides for rodents, herbicides for weeds, and fungicides for microorganisms. According to the U.S. Geological Survey, approximately one billion pounds of these chemicals are used in the United States every year.

But pesticides can also contaminate soil, water, and other vegetation, as well as kill many non-target species. Exposure to these chemicals is dangerous for human health.

According to a new study, researchers from Pennsylvania State University have developed a way to bottle the “smell of fear” produced by predators in order to repel and disrupt pests naturally without the need for these harsh substances. The researchers recently presented their findings at the American Chemical Society meeting.

Aphids happen to be a favorite food of ladybugs. Aphids and other herbivorous insects will steer clear of fields and gardens if they smell predators nearby. The researchers identified and extracted the volatile odor profile from ladybugs. The researchers used the compounds to create a special odor blend that can be used in an essential oil diffuser to spread the scent across a garden or field.

The research team plans to conduct field tests to see if the effects outside are similar to what was observed in the lab. A natural and effective pest repellent would be a big win for people and the planet.

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Protecting gardens and crops from insects using the ‘smell of fear’

Protecting gardens and crops from insects using the ‘smell of fear’ (YouTube)

Photo, posted May 10, 2011, courtesy of DM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Compost And Landfills | Earth Wise

January 19, 2021 By EarthWise Leave a Comment

Composting is popular as a way to keep solid waste out of landfills and many people turn much of their kitchen waste into rich soil amendments. Cities and towns across the country have composting programs that collect waste from residents to produce large quantities of compost rather than adding the waste to landfills. A new study from North Carolina State University looked into the environmental benefits of actually using compost at landfills.

Most municipal composting programs require that the compost they produce gets used “beneficially”. The new research shows that using compost as an alternative daily cover at landfills is competitive and often superior to the use of compost as a soil amendment in terms of its environmental benefits.

Landfills apply a layer of daily cover to reduce odors, reduce windblown debris, and keep vermin out of landfill waste. Federal regulations require six inches of soil as a daily cover.

Compost from food waste in particular is not always suitable for soil amendment in gardens and agricultural fields because it often contains broken glass and other contaminants.

The North Carolina State study looked at the environmental impact of using compost as daily cover in landfills compared with its use as a soil amendment. They looked at global warming potential, acidification potential, eutrophication (which is the amount of nutrients released to ground and surface water), cumulative energy demand, and the depletion of resources.

The study concluded that using compost as landfill daily cover is environmentally superior with regard to eutrophication, acidification, and global warming potential. On the other hand, soil amendment was better in terms of resource depletion and cumulative energy demand.

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Applying Compost to Landfills Could Have Environmental Benefits

Photo, posted April 22, 2008, courtesy of Alachua County via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hacking Photosynthesis | Earth Wise

September 14, 2020 By EarthWise Leave a Comment

A team led by the University of Illinois has been pursuing a project called Realizing Increased Photosynthetic Efficiency or RIPE, which has the aim of improving photosynthesis in order to provide farmers with higher-yielding crops in an increasingly challenging climate. Photosynthesis is the natural, sunlight-powered process that plants use to convert carbon dioxide into sugars that fuel growth, development, and for us, crop yield.

If we think of photosynthesis as a factory line composed of multiple machines, the growth of plants is limited by the slowest machines in the line. The RIPE project has identified some steps in photosynthesis that are slower than others and are attempting to enable plants to build more machines to speed up those slower steps.

The researchers modeled a total of 170 steps in the process of photosynthesis to identify how plants could manufacture sugars more efficiently. In the study, the team increased crop growth by 27% by resolving two constraints: one in the first part of photosynthesis where plants turn light energy into chemical energy and one in the second part when carbon dioxide is turned into sugars.

The researchers effectively hacked photosynthesis by adding a more efficient transport protein from algae to enhance the energy conversion process.

In the greenhouse, these changes improved crop productivity by 52%, but in field trials, which are a more important test, these photosynthetic hacks boosted crop production by 27%.

Ultimately, the team hopes to translate these discoveries to a series of staple food crops, such as cassava, cowpea, corn, soybean and rice, which are needed to feed the world’s growing population this century.

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