VOA慢速英语--Are Forests an Answer to Carbon Pollution?

Burning coal for energy adds planet-warming carbon dioxide, or CO2, to Earth’s atmosphere. As the planet heats up, experts warn that simply cutting greenhouse gas emissions 1 will not be enough to avoid possibly disastrous 2 levels of global warming.

CO2 must also be removed from the atmosphere, they say.

Existing experimental machines that pull CO2 directly from the air are too costly 3 to be widely used.

But a new report from the U.S. National Academy of Sciences, Engineering and Medicine says effective carbon-removal technology already exists.

It is not costly, or even complex science. It is forests.

The report explains that planting trees and overseeing forests are cost-effective ways to clean the air. They also work well across large areas.

Forests used to cover large areas of the Appalachian Mountains in the eastern United States. In the state of West Virginia, a kind of mining known as strip mining left the land there bare, without trees. Now experts are working to bring back the forests that once covered much of the state.

West Virginia's Monongahela National Forest is home to a rare group of trees. They are called virgin 4 woods; they have never been touched by humans.

Shane Jones is a biologist with the U.S. Forest Service.

"Living in the East, there's not many places you can go and be untouched by Man."

Jones says the trees there were missed by mistake when the surrounding forest was cut down for wood many years ago.

That mistake turned out to be a good thing; red spruce forests such as those in the Monongahela are great at taking CO2 out of the atmosphere and locking it into the soil.

Jones explains as he runs his hand through the dark black earth beside a tree.

"See all that organic material? It's black because it's incredibly high in carbon."

Over the years, coal mining and cutting forests took over 90 percent of the red spruce forests from the Appalachian Mountains.

Now, as the planet warms, the need for forests to remove coal’s CO2 is increasingly urgent.

Chris Barton works for the University of Kentucky. As he walks along the Appalachian land, he says the needs of warm-weather rainforests get most of the world’s attention.

"But here in the temperate 5 region of the world, in Appalachia, four hours away from Washington, D.C., we have billions of trees that potentially we could be planting."

So, Barton started a group called Green Forests Work. Its members aim to put trees back on the roughly 400,000 hectares of land that was cleared away by strip mining.

However, Barton explains, the land has problems.

"If you went out and planted trees on these sites, they just didn't grow. The ground was way too compacted. Water didn't infiltrate 6. Roots can't penetrate 7. Oxygen can't circulate in those environments."

The solution? Using heavy equipment, workers tear up the ground. The process lets the trees they plant put down roots.

Barton says not everyone believes the solution is a good idea.

"We've had a lot of people kinda look at us twice. But the really interesting thing about it is, after we do it, there's no question that that was the right thing to do."

And it has worked. Forests are coming back to the grounds.

Scientists say that, in West Virginia alone, restoring red spruce forests to the area could send what is equal to 56 million barrels of oil into the ground. But it will take time. A long time.

Around the world, experts say, nature offers powerful tools to fight climate change. But patience is needed, Jones says.

"It's really awesome 8 to see a tree planted eight years ago that's now waist high. But at the end of the day, at the end of my day, we're barely getting started. Because our main goal with the restoration work that we do here is to basically take actions to then let nature take over."

Nature works, but slowly, in its own time.

I’m Anne Ball.

Words in This Story

greenhouse gas emissions – n. gases that come out of cars and factories, etc. that trap heat in the atmosphere and great a warming of the planet

global – adj. of, relating to or involving the entire world

temperate – adj. moderate climate that lacks extremes

compacted – adj. having a dense 9 structure or parts closely packed together

infiltrate – v. to pass through

penetrate – v. to gain entrance to, or pass into

awesome – adj. causing feeling of fear and wonderful, extremely good