Tag Archives: carbon sinks

Planting Trees Can be Bad for the Planet

Some scientists argue that deforestation is not always harmful for the planet. Christopher A. Williams, a professor at Clark University’s Graduate School of Geography (Worcester, Massachusetts), says that instead of warming up the Earth, deforestation can actually cool it down. (See Climate impacts of U.S. forest loss span net warming to net cooling, Feb. 2021) But some experts are concerned that Williams’ work is likely to be misconstrued as permission to continue deforesting, which is not his intention.

It’s widely accepted that our existing forests are vital carbon sinks, and the best course of action is to stop deforestation, while rewilding and reforesting areas already lost. Deforestation contributes to climate change, can cause wildfires, desertification, soil erosion and most of all – releases huge amounts of carbon dioxide which causes global warming.

While the above may be true, Williams’ new research argues that there are two factors we are not acknowledging: the significance of location and something known as ‘the albedo effect’. Put simply, ‘the albedo effect’ is the process in which forests retain heat. Forests tend to be darker than other surfaces, which means they absorb more sunlight and hold onto heat, explains Williams. As a result, some scientists believe that deforestation gets rid of unwanted heat which is contributing to global warming.

“We found that in some parts of the country like the Intermountain West, more forest actually leads to a hotter planet when we consider the full climate impacts from both carbon and albedo effects,” says Professor Williams. He adds that it is important to consider the albedo effect of forests alongside their well-known carbon storage when aiming to cool the planet.

The team discovered that for approximately one quarter of the US, forest loss causes a persistent net cooling because the albedo effect outweighs the carbon effect.  “It is all about putting the right trees in the right place,” explains Williams, “and studies like ours can help identify where the potential for cooling is greatest.”

For instance, loss of forests east of the Mississippi River caused planetary warming, while forest loss in the Intermountain and Rocky Mountain West led to a net cooling. “If we fail to consider both the carbon and the albedo effects, large-scale tree-planting initiatives, such as Canada’s 2Billion Trees Initiative and The Nature Conservancy’s Plant a Billion Trees campaign, could end up placing trees in locations that are counterproductive for cooling the climate system,” he says.


How Mining Waste Can Help us Deal with Climate Change

Every year, mining and industrial activity generates billions of tons of slurries, gravel, and other wastes that have a high pH.

These alkaline wastes, which sit either behind fragile dams or heaped in massive piles, present a threat to people and ecosystems. But these wastes could also help the world avert climate disaster. Reacting these wastes with carbon dioxide (CO2) from the air solidifies them and makes them easier to handle.

At the same time, carrying out this type of an operation on a global scale could trap between 310 million to 4 billion tons of CO2 annually, according to recent surveys. That could provide the world with a much needed means of lowering atmospheric CO2.

But there are major hurdles. Governments will need to offer incentives for mineralization on the massive scale needed to make a dent in atmospheric carbon. And engineers will need to figure out how to harness the wastes while preventing the release of heavy metals and radioactivity locked in the material…

If regulators verified mines and other alkaline waste producers as CO2 sequestration sites…incentives would skyrocket, companies could claim tax benefits, and industry might start to tackle climate change on the grand scale that’s necessary.

Excerpt from Robert F. Service, The Carbon Vault, Science, Sept. 4, 2020

The Green Climate Fund and COVID-19

 The Green Climate Fund has promised developing nations it will ramp up efforts to help them tackle climate challenges as they strive to recover from the coronavirus pandemic, approving $879 million in backing for 15 new projects around the world…The Green Climate Fund (GCF) was set up under U.N. climate talks in 2010 to help developing nations tackle global warming, and started allocating money in 2015….

Small island states have criticised the pace and size of GCF assistance…Fiji’s U.N. Ambassador Satyendra Prasad said COVID-19 risked worsening the already high debt burden of small island nations, as tourism dived…The GCF  approved in August 2020 three new projects for island nations, including strengthening buildings to withstand hurricanes in Antigua and Barbuda, and installing solar power systems on farmland on Fiji’s Ovalau island.

It also gave the green light to payments rewarding reductions in deforestation in Colombia and Indonesia between 2014 and 2016. But more than 80 green groups opposed such funding. They said deforestation had since spiked and countries should not be rewarded for “paper reductions” in carbon emissions calculated from favourable baselines…. [T]he fund should take a hard look at whether the forest emission reductions it is paying for would be permanent.  It should also ensure the funding protects and benefits forest communities and indigenous people…

Other new projects included one for zero-deforestation cocoa production in Ivory Coast, providing rural villages in Senegal and Afghanistan with solar mini-grids, and conserving biodiversity on Indian Ocean islands.  The fund said initiatives like these would create jobs and support a green recovery from the coronavirus crisis.

Excerpts from Climate fund for poor nations vows to drive green COVID recovery, Reuters, Aug. 22, 2020

Don’t Cut that Tree!

A revolutionary new approach to measuring changes in forest carbon density has helped scientists determine that the tropics now emit more carbon than they capture, countering their role as a net carbon “sink.”*

“These findings provide the world with a wakeup call on forests,” said scientist Alessandro Baccini, the report’s lead author….Forests are the only carbon capture and storage ‘technology’ we have in our grasp that is safe, proven, inexpensive, immediately available at scale, and capable of providing beneficial ripple effects—from regulating rainfall patterns to providing livelihoods to indigenous communities.”

Using 12 years (2003-2014) of satellite imagery, laser remote sensing technology and field measurements, Baccini and his team were able to capture losses in forest carbon from wholesale deforestation as well as from more difficult-to-measure fine-scale degradation and disturbance …from smallholder farmers removing individual trees for fuel wood. These losses can be relatively small in any one place, but added up across large areas they become considerable.

[T] he researchers discovered that tropics represent a net source of carbon to the atmosphere — about 425 teragrams of carbon annually – which is more than the annual emissions from all cars and trucks in the United States.

Excerpts from New approach to measuring forest carbon density shows tropics now emit more carbon than they capture, Woods Hole Research Institute Press Release, Sept. 28, 2017

*Tropical forests are a net carbon source based on aboveground measurements of gain and loss by A. Baccini et al., Science, Sept. 28, 2017