It's amazing how fragile the atmosphere looks from space, said American astronaut Mary Cleave. All we have is a thin film of air to protect us.
"When you look at your planet from space, it's beautiful, fragile, and there's this little thin layer all the way around: our atmosphere. And that's the only thing that protects us from the really bad vacuum in outer space. This little fragile layer, the atmosphere, is part of our life support system. We need to be really careful with it." —Mary Cleave
That atmosphere is something we all share.
"Our atmosphere connects us all. What happens in Africa affects North America. What happens in North America affects Asia." —Dan Barry, American astronaut
Views from space show the destruction humans have caused since the dawn of the industrial age.
"Less than 550 humans have orbited the Earth. Those of us lucky enough to have done so more than once have not only heard about the negative impact that the industrial age has had on our planet, we've seen it with our own eyes." —Michael López-Alegría, American astronaut
Ongoing human catastrophes, like deforestation, are easily visible, too.
"The view from space is just breathtaking. And at the same time we recognize deforestation and wildfires, and so on, which are related to climate change." —Naoko Yamazaki, Japanese astronaut
It's also easy to see lakes dry up and pollution spread.
"We astronauts have been witnessing the continued shrinking of the Aral Sea, the burning rain forests along the Amazon and in Indonesia, the polluted air over industrial zones, and the dirty water at the river deltas." —Ernst Messerschmid, German astronaut
If we don't act now on climate change, things could spiral out of control.
"This is the biggest problem the world has to face right now. And we're at a point now where we really have to take action and make the changes to try to ward off the worst effects which might come down the pipe." —Greg Linteris, American astronaut
People in power must work together if we want to temper climate change and its disruptive force, the astronauts say.
"To make the changes we need to make and to reach a safer future, we will need the resources of everybody here — the scientists, the policy makers, and the industrialists — all working together towards a common goal. And that goal is a planet that can continue to support life." —Piers Sellers, American astronaut
It's also crucial that we educate future generations to be better stewards than we have been.
"Our course would be better served if in addition to what [the Paris climate change] conference seeks to achieve, this world body focuses also equally on educating the next generation so that it grows up with the understanding that sustainable development is impossible if it is accompanied by non-sustainable consumption." —Rakesh Sharma, Indian cosmonaut
We're the only caretakers of Earth, the astronauts say, so it's our job to watch over of the planet.
"We are citizens of space, and stewards of Earth. We need to take actions to build [a] global climate alliance in order to protect our environment." —Soichi Noguchi, Japanese astronaut
Dutch astronaut Wubbo Ockels suggested that the Earth has cancer, just like him, in a heartbreaking message.
"Suppose I can transfer the experience which I have to you. Then you would go out and see the Earth. And when you have let's say the spirit and the insight and the attitude of an astronaut, you start to love the Earth. And if you really love something, you don't want to lose it. Our Earth has cancer. I have cancer, too." —Wubbo Ockels
Ockels died the day after recording his message.
You can watch the astronauts' entire video below.
Kelly Dickerson wrote a previous version of this post.
