B1 中級 美國腔 4637 分類 收藏
The earth has an elegant cycle of life.
It's the story of carbon.
And over billions of years, it has evolved to look something like this.
It starts with a plant.
Plants and microorganisms absorb carbon dioxide from the atmosphere.
Then they use energy from the sun to convert that carbon into oxygen and sugar, which they use to grow.
And as they grow, they emit some carbon back into the atmosphere.
But all plants eventually die.
And some are consumed by bacteria, others by larger beasts.
These animals eat plants for energy.
And they breathe out carbon.
But eventually, those animals die, too.
And they end up in the ground.
Meanwhile, a similar thing happens in the ocean.
Coral and plankton need carbon from the water to survive.
Luckily, the ocean has carbon because it absorbs some from the atmosphere.
And, when rain falls to the earth, it grabs some carbon from the atmosphere and from rocks.
And flows into the ocean, where the coral and plankton use carbon to grow.
Or other animals use it to grow.
But just like animals, the coral and plankton die, too.
In short, all living things are made of carbon, and they eventually end up in the ground.
Some of that carbon will eventually get back to the atmosphere.
But some of it normally stays in the ground.
Usually, dead things decay and turn into rocks.
Eventually, they're crushed, and extreme heat and pressure causes them to melt and emit the carbon, which is trapped underground.
Over time, that trapped carbon eventually escapes into the atmosphere when volcanoes erupt.
And the cycle starts again.
But occasionally, dead plants and animals don't turn into rock.
They don't decay fast enough, so they turn into oil, coal, or natural gas.
This carbon gets stuck in the ground.
This is the elegant system that keeps carbon cycling through Earth at a steady pace.
Carbon in the atmosphere keeps some heat from leaving Earth.
It keeps Earth at a stable temperature.
But very recently, one of these animals started to dig up the carbon in the ground.
They took the carbon that was stuck in the ground and put it back into the atmosphere.
They did this so much, in such a short time span, that this cycle was disrupted.
Too much carbon was being put into the atmosphere.
Heat that would normally be able to escape bounced back and stayed on Earth.
And Earth started to get warmer and warmer.
Really recently, just a few months ago, more than 100 bipedal scientists said they might only have 12 years to stop a disastrous amount of warming.
So these animals not only need to stop putting carbon in the atmosphere, but also get carbon out of the atmosphere.
They found that one way to remove carbon is to grow more plants.
They could stop cutting down trees.
Or raise livestock in ways that help restore grass.
Another way is to let plants suck up carbon from the atmosphere but then burn them for energy.
And then trapping the carbon they emit underground.
They could also build machines to suck air from the atmosphere and filter out the carbon.
But they haven't figured out how to do this fast enough.
There are many ways these animals can tweak this cycle to suck carbon out of the atmosphere.
A combination of them is probably the best way forward.
But, first, these animals need to figure out how to stop putting it there in the first place.



【環境教育】人類活動破壞碳循環 (How humans disrupted a cycle essential to all life)

4637 分類 收藏
Jessieeee 發佈於 2019 年 4 月 26 日    Jessieeee 翻譯    Evangeline 審核
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