Solving the climate crisis is the greatest and most complex challenge that homo sapiens have ever faced. The main solution, however, is so simple that even a small child can understand it. We have to stop our emissions of greenhouse gases.

We’re running the most dangerous experiment in history right now, which is to see how much carbon dioxide the atmosphere… can handle before there is an environmental catastrophe.

I would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy, without pollution or global warming.

By the time we see that climate change is really bad, your ability to fix it is extremely limited… The carbon gets up there, but the heating effect is delayed. And then the effect of that heat on the species and ecosystem is delayed. That means that even when you turn virtuous, things are actually going to get worse for quite a while.

The thing that’s made me open my eyes to what was happening to the environment and climate was films and documentaries.

I mean, people aren’t continuing like this and not doing anything because they are evil, or because they don’t want to. We aren’t destroying the biosphere because we are selfish. We are doing it simply because we are unaware.

For way too long the politicians and people in power have got away with not doing anything at all to fight the climate crisis and ecological crisis.

Some people say that I should study to become a climate scientist so that I can ‚solve the climate crisis.‘ But the climate crisis has already been solved. We already have all the facts and solutions. All we have to do is to wake up and change.

I would like to see a future where artists think that they have a right to contemplate things like global warming.

I have a company, and I’ve got to think about that. I’m trying to do my best there, and that’s a much harder task. We recycle as much as possible, and we conserve. But I’ve always been one to save everything – I even walk up stairs on the very inside or the very outside to not wear out the tread.

In California, they don’t throw their garbage away – they make it into TV shows.

When I was 11 I became very depressed. It had a lot to do with the climate and ecological crisis. I thought everything was just so wrong and nothing was happening and there’s no point in anything.

The nation that destroys its soil destroys itself.

Even if producing CO2 was good for the environment, given that we’re going to run out of hydrocarbons, we need to find some sustainable means of operating.

War contributes greatly to global warming, which shouldn’t surprise us. All those bombs going off, all those rockets, all those planes and helicopters. All that fuel of various kinds being used. It pollutes the air and water of this very fragile and interconnected planet.

You could warm Mars up, over time, with greenhouse gases.

The effects of climate change are real and must be acted on.

My message is that if we do not care about the climate crisis and if we do not act now then almost no other question is going to matter in the future.

We have one planet in our solar system that’s habitable, and that’s the Earth, and space travel can transform things back here for the better. First of all, by just having people go to space and look back on this fragile planet we live on. People have come back transformed and have done fantastic things.

Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it’s about 20 tons. For people in poor countries, it’s less than one ton. It’s an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero.

When we have peace, then we have a chance to save the planet. But if we are not united in peace, if we do not practice mindful consumption, we cannot save our planet.

It felt like I was the only one who cared about the climate and the ecological crisis. My parents didn’t care about it, my classmates didn’t care about it, my relatives didn’t care about this. I mean nobody I knew cared about this and I felt like I was the only one.

We need enlightenment, not just individually but collectively, to save the planet. We need to awaken ourselves. We need to practice mindfulness if we want to have a future, if we want to save ourselves and the planet.

I remember when I was younger, and in school, our teachers showed us films of plastic in the ocean, starving polar bears and so on. I cried through all the movies. My classmates were concerned when they watched the film, but when it stopped, they started thinking about other things. I couldn’t do that. Those pictures were stuck in my head.

The main message we want to get out there is that climate change is caused by the rotten economic system.

The main message of Climate Revolution is that climate change is caused by the rotten financial system we’ve got, designed to create poverty and rip off any profits for a small amount of rich people. Meanwhile, it destroys the earth.

I don’t use any animal products, both because of ethical and environmental and climate reasons.

Climate change is a terrible problem, and it absolutely needs to be solved. It deserves to be a huge priority.

Many people seem to have this double moral. They say one thing and then do another thing. They say that the climate crisis is very important and yet they do nothing about it.

By stopping flying, you don’t only reduce your own carbon footprint but also that sends a signal to other people around you that the climate crisis is a real thing and that helps push a political movement.

Avoiding climate breakdown will require cathedral thinking. We must lay the foundation while we may not know exactly how to build the ceiling.

People are unaware of what is going on. When I talk to people, they know the basics, they know the planet is warming because of greenhouse gases… but they don’t know the actual consequence of that.

In Tanzania, the chimps are isolated in a very tiny patch of forest. I flew over it 13 years ago and realized that, basically, all the trees had gone, that people all around the park are struggling to survive. It became very clear that there was no way to protect the chimps while the people were in this dire circumstance.

Our economic system, run for profit and waste and based primarily on the extractive industries, is the cause of climate change. We have wasted the earth’s treasure and we can no longer exploit it cheaply.

The Chinese have figured out that they have a giant environmental problem. Folks in Beijing, some days, literally can’t breathe. Over a million Chinese die prematurely every year because of air pollution.

The threat to the planet is us. It’s actually not a threat to the planet – it’s a threat to us.

There’s 20 companies that I have investments in – some batteries, some solar-thermal, one big nuclear thing. We need hundreds and hundreds of companies like that, so that in a 20-year time frame we really are starting to change the energy infrastructure.

To shake your rump is to be environmentally aware.

I think that once you fully understand the climate and ecological emergencies, then you know what you can do as well. And, of course, there’s a lot of things you can do in your everyday life, but we cannot be focusing on these individual things you can do. We have to see the full picture.

I threw my cup away when I saw a child drinking from his hands at the trough.

Some people say that the climate crisis is something that we will have created, but that is not true, because if everyone is guilty then no one is to blame. And someone is to blame.

The climate crisis is both the easiest and the hardest issue we have ever faced. The easiest because we know what we must do. We must stop the emissions of greenhouse gases. The hardest because our current economics are still totally dependent on burning fossil fuels, and thereby destroying ecosystems in order to create everlasting economic growth.

There aren’t many things that are universally cool, and it’s cool not to litter. I’d never do it.

The situation the Earth is in today has been created by unmindful production and unmindful consumption. We consume to forget our worries and our anxieties. Tranquilising ourselves with over-consumption is not the way.

I thought my life was mapped out. Research, living in the forest, teaching and writing. But in ’86 I went to a conference and realised the chimpanzees were disappearing. I had worldwide recognition and a gift of communication. I had to use them.

I have been on the road and visited numerous places and met people from all over the globe. I can say that it looks nearly the same everywhere I have been: The climate crisis is ignored by people in charge, despite the science being crystal clear.

We should no longer measure our wealth and success in the graph that shows economic growth, but in the curve that shows the emissions of greenhouse gases.

When the well is dry, they know the worth of water.

As you heat the planet up, it’s just like boiling a pot.

In Buddhism, we talk of meditation as an act of awakening, to be awake to the fact that the earth is in danger and living species are in danger.

Many people say that this is not an easy issue, we cannot just say that this is how it is, it’s not black and white. But I say that this is black and white. Either we stop the emissions or we don’t. There are no gray areas when it comes to survival.

This is the moment when we must come together to save this planet. Let us resolve that we will not leave our children a world where the oceans rise and famine spreads and terrible storms devastate our lands.

When I was maybe eight or nine years old, I first learned about the climate crisis in school. My teachers taught me about it and we saw films and pictures of plastic in the ocean and extreme weather events. Those pictures were just stuck in my head; I thought, there is no point in anything.

If you can’t eat it, shoot it, or wear it, don’t bring it.

We can’t just continue living as if there was no tomorrow, because there is a tomorrow.

It is hard sometimes to always be at the centre of attention, but when you talk about me you also have to talk about the climate.

We are at a time in history where everyone with any insight of the climate crisis that threatens our civilisation – and the entire biosphere – must speak out in clear language, no matter how uncomfortable and unprofitable that may be.

We are living in the beginning of a mass extinction and our climate is breaking down.

People tell me that they are so hopeful when they see me and other children ‚school-striking,‘ and they say, ‚Oh the children are going to save us.‘ But no, we aren’t. We are too young to be able to do that. We don’t have time to wait for us to grow up and fix this in the future.

I don’t care about hate and threats from climate crisis deniers. I just ignore them.