US President Barack Obama has spoken about the immediate threat of climate change and how the nation plans to address global warming in the future.
As part of his State of the Union 2015 speech, Obama pledged to make the US a world leader on climate change policy, harking to his recent deal with China that committed both nations to reduce greenhouse emissions over next few decades.
"I've heard some folks try to dodge the evidence by saying they're not scientists; that we don't have enough information to act. Well, I'm not a scientist, either," he said.
"The best scientists in the world are all telling us that our activities are changing the climate, and if we do not act forcefully, we'll continue to see rising oceans, longer, hotter heat waves, dangerous droughts and floods, and massive disruptions that can trigger greater migration, conflict, and hunger around the globe."
Obama's top 10 quotes on climate change
1. SOTU 2015
"2014 was the planet's warmest year on record. Now, one year doesn't make a trend, but this does - 14 of the 15 warmest years on record have all fallen in the first 15 years of this century. The Pentagon says that climate change poses immediate risks to our national security. We should act like it."
2. University of California, Irvine, graduation commencement ceremony (2014)
"And today's Congress, though, is full of folks who stubbornly and automatically reject the scientific evidence about climate change. They will tell you it is a hoax, or a fad. One member of Congress actually says the world is cooling ... There are some who also duck the question. They say -- when they're asked about climate change, they say, 'Hey, look, I'm not a scientist'. And I'll translate that for you. What that really means is, 'I know that manmade climate change really is happening, but if I admit it, I'll be run out of town by a radical fringe that thinks climate science is a liberal plot, so I'm not going to admit it'."
3. University of California, Irvine, graduation commencement ceremony (2014)
"Now, part of what's unique about climate change, though, is the nature of some of the opposition to action. It's pretty rare that you'll encounter somebody who says the problem you're trying to solve simply doesn't exist. When President Kennedy set us on a course for the moon, there were a number of people who made a serious case that it wouldn't be worth it; it was going to be too expensive, it was going to be too hard, it would take too long. But nobody ignored the science. I don't remember anybody saying that the moon wasn't there or that it was made of cheese."
4. Georgetown University (2013)
"The overwhelming judgment of science - of chemistry and physics and millions of measurements - has put all that to rest. Ninety-seven percent of scientists, including, by the way, some who originally disputed the data, have now put that to rest. They've acknowledged the planet is warming and human activity is contributing to it.
"So the question now is whether we will have the courage to act before it's too late. And how we answer will have a profound impact on the world that we leave behind not just to you, but to your children and to your grandchildren."
5. UN Climate Change Summit (2014)
"We cannot condemn our children, and their children, to a future that is beyond their capacity to repair. Not when we have the means - the technological innovation and the scientific imagination - to begin the work of repairing it right now."
6. League of Conservation Voters Capital Dinner (2014)
"Today, about 40% of America's carbon pollution comes from our power plants. There are no federal limits to the amount those plants can pump into the air. None. We limit the amount of toxic chemicals like mercury, and sulphur, and arsenic in our air and water, but power plants can dump as much carbon pollution into our atmosphere as they want. It's not smart, it's not right, it's not safe, and I determined it needs to stop."
7. First press conference after winning re-election (2012)
"I am a firm believer that climate change is real, that it is impacted by human behaviour and carbon emissions. And as a consequence, I think we've got an obligation to future generations to do something about it.
"What we do know is the temperature around the globe is increasing faster than was predicted even 10 years ago. We do know that the Arctic ice cap is melting faster than was predicted even five years ago. We do know that there have been an extraordinarily large number of severe weather events here in North America, but also around the globe. You can expect that you'll hear more from me in the coming months and years about how we can shape an agenda that garners bipartisan support and helps move this agenda forward."
8. SOTU 2010
"I know there have been questions about whether we can afford such changes in a tough economy. I know that there are those who disagree with the overwhelming scientific evidence on climate change. But here's the thing – even if you doubt the evidence, providing incentives for energy-efficiency and clean energy are the right thing to do for our future – because the nation that leads the clean energy economy will be the nation that leads the global economy. And America must be that nation."
9. Copenhagen climate summit (2009)
"Unchecked, climate change will pose unacceptable risks to our security, our economies, and our planet. That much we know. So the question before us is no longer the nature of the challenge – the question is our capacity to meet it. For while the reality of climate change is not in doubt, our ability to take collective action hangs in the balance."
10. Energy Independence and the Safety of Our Planet (2006)
"All across the world, in every kind of environment and region known to man, increasingly dangerous weather patterns and devastating storms are abruptly putting an end to the long-running debate over whether or not climate change is real. Not only is it real, it's here, and its effects are giving rise to a frighteningly new global phenomenon: the man-made natural disaster."