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Planting Rocks to Crush Climate Change

August 20, 2023

Maui’s Water Disputes Highlighted by Disaster

In addition to being the deadliest wildfire in the U.S. in 100 years, the disaster on Maui is likely to have devastating effects on the island’s ecosystems. Maui has some of the oldest coral reefs in all of Hawai'i, which could be killed from ash and runoff from the fire. Also, as the Guardian reports, invertebrates that feed on plankton might ingest contaminants, mistaking them for food.

Lahaina, Maui, August 10, 2023  |  Credit: U.S. National Guard media by Master Sgt. Andrew Jackson

The coral reefs are already stressed from pollution and overfishing, and portions were bleached about eight years ago when water temperature rose under El Niño conditions, according to the Washington Post. The reefs are important not only as fish habitat, they also break surf that otherwise could cause coastlines to deteriorate.

The disaster is bringing attention to historic water disputes on Maui where hotels and resorts sport lush green gardens with pools and fountains, as other parts of the island suffer from drought. In the 1800s, before Hawai'i was colonized and became a plantation economy based upon sugar and pineapple, water was used for farming and subsistence, but now much is diverted for resorts and development and has transformed the Lahaina area—where the wildfires were most destructive—into a desert.

Naomi Klein and Hawai’i law professor Kapuaʻala Sproat wrote in the Guardian that Indigenous communities who have lived on Maui for many generations remain cut off from water for drinking, washing, and crop irrigation. SFGATE reported that people on the island where the water originates are hurting for it.  According to a spokesperson for Sierra Club Maui Group, there are shortages from over-tourism. The coastline where the largest wildfire raged receives little rain–with less than ten inches per year.

Study Shows Link Between Wildfire Smoke and Developing Dementia

Recent research shows that those who live in areas with wildfire smoke have an increased risk of developing dementia. A new study examined different sources of contaminants, including those from traffic and coal combustion. They found small particles from wildfires and agriculture are more damaging to the brain than the others. The study looked at tiny inhalable particles, 30 times smaller than the width of a human hair.  Smoke from wildfires has already been known to worsen lung conditions like asthma and COPD and can increase risk of heart attack and stroke. It can also cause inflammation in the liver, kidneys, and other organs, in addition to the new evidence of its effects on the brain.

Credit: Malachi Brooks/Unsplash

One of the researchers, Dr. Sara Dubowsky Adar of the University of Michigan, told CNN that they were surprised when agriculture and wildfires stood out.  She noted that it makes a lot of sense because they were looking at impacts on the brain. Agriculture uses a lot of pesticides, some of which are neurotoxins.  She added that wildfire smoke includes burned structures like gas stations and homes.

The exact way particulate pollution leads to dementia hasn’t been determined, but some theories suggest it gets into the brain through the nose and causes neuron cells to die. It’s also a possibility that the small particles modify proteins that act on the brain.

As of Saturday, August 19, 95 wildfires were burning in 15 states. In British Columbia alone, almost 400 fires were raging. According to the BBC, it’s the worst wildfire season on record in Canada. Smoke contaminants can travel far from where a fire originates, affecting many with polluted air.

The study was published in the journal JAMA Internal Medicine.

A Natural Insecticide from a Popular Plant

The aloe vera plant (Aloe barbadensis) has been used for centuries to moisturize skin, improve gut health, and heal wounds. But while the plant’s sap is in high demand for its health and beauty properties, the rinds are tossed out as agricultural waste, which if left to rot, release methane and contribute to the climate crisis.


Aloe rinds, like those pictured here, contain bioactive compounds that could be used to deter insects from feasting on agricultural fields.  |  Credit: Nazmul Huda

But aloe trash could soon be treasure. According to new research, the plant’s peels are a natural pesticide. The discovery came after researchers from the University of Texas, Rio Grande Valley visited a local organic aloe nursery and noticed that insects were attacking leaves of other plants but leaving aloe alone. They took the rinds back to the lab and discovered they contained at least six bioactive compounds that have insecticidal properties which could be used in agriculture. Pesticides are considered a threat to human health, so finding natural alternatives would be consequential.

Lead researcher Debasish Bandyopadhyay, PhD, said the aloe-derived pesticides could help farmers in areas where insects are a major threat, such as in regions of Africa, the tropical and subtropical regions of the Americas, and parts of India, to improve food security. Also, being able to recycle the peels could create a revenue stream for aloe vera growers.

Planting Rocks Could Help Climate Crisis

To keep global temperatures below 1.5 degrees Celsius above pre-industrial levels and avoid climate catastrophe, we need not only to reduce emissions as soon as possible but also, as most experts agree, to remove carbon already in the atmosphere. One way to get there is by planting more trees, but according to new research, we should also be planting…rocks.

Enhanced rock weathering improves soil health, sequesters carbon, and combats ocean acidification.   |  Credit: AGU

Volcanic rock to be precise. Researchers from Yale University recently modeled how adding crushed basalt—a rock that forms as lava cools—to croplands could help farms store significant amounts of carbon through a process called “enhanced rock weathering.”

When rain falls, it absorbs CO2 in the atmosphere and becomes more acidic. That acid rain then reacts with rocks on the ground and is converted to carbonates that sequester the carbon. Normally, this natural geologic weathering happens slowly, but research has found that by using volcanic rock dust, it can be accelerated.

How much? The authors estimated that if the basalt bits were spread across all of the world’s croplands for the rest of this century, 215 billion tons of carbon dioxide could be removed, keeping climate goals within reach. What’s more, the carbonates improve soil health, and as they make their way into waterways and eventually to the sea, they can reduce ocean acidification.

Ironically, the team says the hotter it gets, the better the enhanced rock weathering works, whereas other methods, such as storing carbon in soils, become less effective with continued warming.  Furthermore, because weathering progresses more quickly in hot and wet environments, it would work faster in tropical regions than higher latitudes. The authors say that farmers already apply tons of limestone to fields to increase productivity, so they could potentially switch to less expensive lava dust and help the planet rock on.

The findings were published in the journal Earth’s Future.