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  • Carbon dioxide, or CO2, is the main greenhouse gas in climate change.

  • So how does CO2 get into our atmosphere?

  • Well, carbon is part of a cycle. It starts with the sun,

  • which heats the Earth's surface with more energy

  • in one hour than the whole world uses in a year.

  • Plants, which are kind of like biological chefs,

  • take that sunlight, and then suck in some CO2 from the air,

  • mix them together, and BAM!

  • They create a stored form of energy, in the form of carbohydrates

  • such as glucose and sucrose.

  • The process is called photosynthesis.

  • When animals like us eat those plants

  • our stomachs convert that food back into energy for our own growth.

  • Greenhouse gases are a byproduct of this process,

  • and are released through waste.

  • If those plants die, they decompose, and tiny microorganisms break down those carbohydrates

  • and again, release greenhouse gases as a byproduct.

  • As you see, energy originates from the sun. It is then transferred as it moves through the food chain.

  • But sometimes, carbon based organisms like plants or animals get stuck in the earth.

  • When this happens, they're compressed under tons of pressure,

  • and turned into carbon-based fossil fuels

  • like oil, coal or natural gas.

  • Since the Industrial Revolution, humans have been pulling those fossil fuels out of the ground

  • and burning them, activating the stored energy

  • to make electricity and power engines.

  • But the thing is it also releases millions of years worth of stored CO2 back into the air.

  • In addition, humans breathe in oxygen and breathe out CO2.

  • But plants do the opposite.

  • Trees suck up huge amounts of CO2, which balances the cycle.

  • Thus, deforestation reduces the plants that store CO2.

  • We're attacking the cycle from both sides.

  • Think of it like a computer. A computer can operate a few programs at a time, right?

  • Normally, when you've finished with a document, you save, and you close it,

  • so as not to overwork the computer.

  • Then, imagine you stopped closing your documents.

  • So they were all open at once.

  • Your computer wouldn't be able to process it all.

  • It would start to slow down, and then to freeze, and eventually it would crash.

  • Which might be where our environment is heading if we keep overloading the carbon cycle.

  • So is there any way to rebalance the ecosystem?

  • What about technology? Technology is defined as a technique to solve a problem.

  • And so, sustainable technologies are those whose output is equal to their input.

  • They do not create negative externalities,

  • such as CO2, in the present or the future.

  • They sort of cancel themselves out to solve the problem.

  • To achieve this, we need to invent sustainable technologies.

  • If we put all the ideas and technologies ever created into one circle,

  • then invention is the pushing of the boundaries of that circle.

  • And the area outside of the circle is infinite,

  • meaning the potential for invention is limitless.

  • Think about some of the incredible clean technologies we have today. [Wind; Electric & Solar Cars; Biogas]

  • [Biofuels; Photosynthetic Algae; Compost] All those ideas have one thing in common.

  • They all came from people. People innovate.

  • People create. It's the limitless potential of creative people

  • to build unimagined technologies that is going to stop climate change

  • and rebalance the ecosystem. And that is something to be hopeful about.

Carbon dioxide, or CO2, is the main greenhouse gas in climate change.

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B1 中級

TED-ED】炭素サイクル - ナサニエル・マニング (【TED-Ed】The carbon cycle - Nathaniel Manning)

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    VoiceTube に公開 2021 年 01 月 14 日
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