Elsa asks: Is the Earth alive?
That kind of depends upon what you mean by “alive”!
Our planet is not itself an organism like a plant or an animal. But it had a beginning (about 4..5 billion years ago by our best estimate), and since then it has been active and changing, both inside and on the surface. Earth’s core generates its own heat, and the motion of the boiling rock in the mantle (the middle layer of the Earth) is what causes the continents to shift and move across the surface of the planet. Landmasses rise above the ocean and sink again; mountain ranges are thrust towards the sky and worn slowly down by the weathering effects of wind and water. Glaciers advance and retreat, and the balance of gases in the atmosphere responds to the changes in plant and animal life. Planet Earth is a complex and dynamic system that changes over time, which certainly sounds more like life than otherwise.
One characteristic of living things is that they reproduce. What would you call it if we sent a colony of humans with Earth plants, animals, fungi, and bacteria to other worlds, to grow and live like we do on Earth? There will be such a colony on Mars within a few decades at most; more distant worlds will be harder to reach, but consider: only seventy years ago, most respected scientists believed it was impossible to send people to the moon. They were not only wrong, they themselves lived to see it happen. “Hard to reach” only makes humans jump higher. When Earth organisms have spread to other planets, is that not a kind of reproduction for our own planet Earth?
Someday there will be an end for Earth. In about 5 billion years, the Sun will grow into a red giant star and swallow up the inner planets (including Earth). So you could say that Earth has a lifespan, like other living things. That brings us to the reason I wanted to answer Elsa’s question on Earth Day.
Some people say that we are destroying our planet with the pollution from our factories, vehicles, and power plants. This is not really true. We can pollute the Earth so badly that it will become toxic and unable to sustain human life. That would be the end of us humans. But it would not be the end of Earth – some form of life would survive, just like it always has. When we care for the Earth, we are caring for ourselves first!
The first Earth Day was on April 22, 1970; today is the 44th Earth Day! Since 1970, we have been celebrating Earth as something that we should respect and treat with care. As a result, our air is cleaner than it was 44 years ago. We have passed laws that make individuals and corporations more responsible than before. There is still much to be done; many people still do not understand that keeping the environment healthy and clean is more than just the right thing to do: it is a matter of our own survival.
We can make a difference every day, not only once a year. By conserving resources, recycling, and always trying to find ways to work smarter and cleaner, we can help return our Planet Earth to the beautiful place it was before we started to change it. Future generations will thank us.
Happy Earth Day!