meaningful

Planting lots of trees is one of many strategies being pursued to combat climate change. Forests absorb carbon dioxide, provide shade, and help regulate temperatures. They also support biodiversity and improve air and water quality.

According to a new study by researchers from the University of California – Riverside, restoring forests to their pre-industrial extent could reduce global average temperatures by 0.34 degrees Celsius. That’s equivalent to about 25% of the warming the Earth has already experienced.

The study models restoring 4.6 million square miles of forest. While previous studies have focused on the role trees play in removing carbon, this research adds that trees also alter atmospheric chemistry in ways that boost their cooling impact.

Trees release natural chemicals called BVOCs – biogenic volatile organic compounds – which interact in the atmosphere to form particles that reflect sunlight and promote cloud formation. These effects enhance the cooling impact of forests, especially in climate models that take these chemical reactions into account.

But not all reforestation is created equal. The benefits of reforestation vary by region, with tropical forests offering stronger cooling and fewer drawbacks. Importantly, the researchers emphasize that meaningful climate benefits don’t require restoring every lost forest. Small, localized efforts can still shift regional climates.

While forest restoration can meaningfully aid climate efforts, the researchers stress that it must complement – not replace – fossil fuel reductions.

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Does planting trees really help cool the planet?

Photo, posted May 20, 2005, courtesy of Ben Britten via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Many experts say that combating global warming will require both drastically reducing the use of fossil fuels and permanently removing billions of tons of CO2 already in the atmosphere. Developing practical, large-scale technologies for carbon removal is a significant challenge.

There is a nearly inexhaustible supply of minerals that are capable of removing carbon dioxide from the atmosphere, but they don’t do it quickly enough to make a significant dent in the ever-growing supply in the atmosphere. In nature, silicate minerals react with water and atmospheric CO2 to form minerals in the process called weathering. But this chemical reaction can take hundreds or even thousands of years.

Researchers at Stanford University have developed a new process for converting slow-weathering silicates into much more reactive minerals that capture and store carbon quickly. The new approach resembles a centuries-old technique for making cement. They combine calcium oxide and another common mineral containing magnesium and silicate ions in a furnace. The result are new materials that, when exposed to water, quickly trap carbon from the atmosphere.

In their experiments, the carbonation process took weeks to months to occur, thousands of times faster than natural weathering.

The idea would be to spread these materials over large land areas to remove CO2 from the air. Meaningful use for trapping carbon would require annual production of millions of tons. But the same kiln designs used to make cement could produce the needed materials using abundant minerals found in many places. In fact, the required minerals are often common leftover materials – or tailings – from mining.

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Scientists discover low-cost way to trap carbon using common rocks

Photo courtesy of Renhour48 via Wikimedia.

Earth Wise is a production of WAMC Northeast Public Radio

Planting trees to cool the planet

Planting lots of trees is one of many strategies being pursued to combat climate change. Forests absorb carbon dioxide, provide shade, and help regulate temperatures. They also support biodiversity and improve air and water quality.

Web Links

Trapping carbon with rocks

Many experts say that combating global warming will require both drastically reducing the use of fossil fuels and permanently removing billions of tons of CO2 already in the atmosphere. Developing practical, large-scale technologies for carbon removal is a significant challenge.

Web Links