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’ve grown accustomed to hotels and drastic climate change.

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

The public is strongly in favor of the Kyoto Protocols, so strongly in favor that a majority of Bush voters thought that he was in favor of it. They are simply unaware.

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

At Virgin, we have always backed the power of the entrepreneur and inventor to find solutions to tricky problems. Why should climate change and the battle against carbon be any different?

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.

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.

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.

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.

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.

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.

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.

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.

I am not deeply involved in Australian politics but I know there are prime ministers, governments around the world who are not acting responsibly in relation to climate change.

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.

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.

Nothing is being done to stop the climate and ecological emergency from happening and to secure the future wellbeing for future generations.

Taking bold action on climate change simply makes good business sense. It’s also the right thing to do for people and the planet. Setting a net-zero GHG emissions target by 2050 will drive innovation, grow jobs, build prosperity, and secure a better world for what will soon be 9 billion people.

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

Sweden is not a green paradise, it has one of the biggest carbon footprints.

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

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

The symbolism of the climate strike is that if you adults don’t give a damn about my future, I won’t either.

It’s not as though we can keep burning coal in our power plants. Coal is a finite resource, too. We must find alternatives, and it’s a better idea to find alternatives sooner then wait until we run out of coal, and in the meantime, put God knows how many trillions of tons of CO2 that used to be buried underground into the atmosphere.

At places like Davos, people like to tell success stories. But their financial success has come with an unthinkable price tag. And on climate change, we have to acknowledge we have failed.

There are two problems for our species‘ survival – nuclear war and environmental catastrophe – and we’re hurtling towards them. Knowingly.

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.

Learning about climate change triggered my depression in the first place. But it was also what got me out of my depression, because there were things I could do to improve the situation. I don’t have time to be depressed anymore.

Some scientists believe climate change is the cause of unprecedented melting of the North Pole, and that effects these very uncertain weather patterns. I think we should listen to those scientists and experts.

What is the use of a house if you haven’t got a tolerable planet to put it on?

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

I want to use my position of leadership to help move along at a faster pace what I believe and know the Obama administration wants to do around the urgency of climate change.

It’s the poorer people in tropical zones who will get really hit by climate change – as well as some ecosystems, which nobody wants to see disappear.

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.

We could have saved the Earth but we were too damned cheap.

Gujarat is the fourth state in the world where we have a separate climate-change department.

Most emissions aren’t caused by individuals, they’re caused by corporations and states.

First, how do we give everyone a fair shot at opportunity and security in this new economy? Second, how do we make technology work for us, and not against us – especially when it comes to solving urgent challenges like climate change? Third, how do we keep America safe and lead the world without becoming its policeman?

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

You should be attacking the carbon emissions, period, and whether it’s cap-and-trade or carbon tax or whatever, that’s the realm in which we should be playing.

We need every person on Earth to acknowledge that climate change is real and encourage each other and our leaders to address the challenge.

The nation that destroys its soil destroys itself.

We shouldn’t be saying ‚Save the planet‘; we should be saying: ‚Save viable conditions in which people can live.‘ That’s what we’re dealing with here.

At first when I heard about climate change, I was a climate denier. I didn’t think it was happening. Because if there really was an existential crisis like that, that would threaten our civilisation, we wouldn’t be focusing on anything else. That would be our first priority. So I didn’t understand how that added up.

Would you bet your paycheck on a weather forecast for tomorrow? If not, then why should this country bet billions on global warming predictions that have even less foundation?

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

I think my message to the politicians who have within their power the ability to make change is, ‚Do you really, really not care about the future of your great-grandchildren? Because if we let the world continue to be destroyed the way we are now, what’s the world going to be like for your great-grandchildren?‘

As I’m traveling around, I meet many small children. And when I look at a small and think how we’ve harmed this beautiful planet since I was that age, I feel a kind of desperation, anger, shame. I don’t know what I feel; I just don’t know what the emotion is.

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

The shift to a cleaner energy economy wont happen overnight, and it will require tough choices along the way. But the debate is settled. Climate change is a fact.

If burning fossil fuels was so bad that it threatened our very existence, how could we just continue like before? Why were there no restrictions? Why wasn’t it made illegal? To me, that did not add up.

We’ve got to keep our eye on what’s happening with Russia and North Korea. We cannot lose sight of domestic policy, either. Healthcare. Immigration. Climate change.

I’m a radical environmentalist; I think the sooner we asphyxiate in our own filth, the better. The world will do better without us. Maybe some fuzzy animals will go with us, but there’ll be plenty of other animals, and they’ll be back.

People are going to buy cheap fertilizer so they can grow enough crops to feed themselves, which will be increasingly difficult with climate change.

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.

The reason we should do a carbon tax is because it’s the right thing to do. It’s economics 101, elementary stuff.

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

Earth might one day soon resemble the planet Venus.

I think there are more politicians in favor of electric cars than against. There are still some that are against, and I think the reasoning for that varies depending on the person, but in some cases, they just don’t believe in climate change – they think oil will last forever.

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