In November 2012, US President-Elect Donald Trump tweeted that global warming is a Chinese hoax. He said that it's part of a plot designed to bring down US business and manufacturing.

"The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive."

In reality there is irrefutable evidence that global warming is happening, and has been made worse by humans. This is backed up by thousands of scientists and decades of research.

Here are the facts:

As if this isn't all worrying enough in and of itself, Trump wants to backtrack on a lot of the progress that has been made recently to try and stop our negative impact on the environment.

He said he wants to dismantle the USA's involvement in the Paris Climate Agreementt — a pledge between world leaders to stop the earth heating up more than 2 degrees Celsius — because it is "bad for US business."

He has also suggested he will appoint Myron Ebell — a famous climate change denier — as the new Administrator of the US Environmental Protection Agency. That's if he doesn't eliminate it altogether.

In the past he also said that wind farms are "disgusting looking" and claimed they are "bad for people's health" — a claim which has since been debunked.

"Not only are wind farms disgusting looking, but even worse they are bad for people's health."

Trump has also expressed the desire to ramp up the fossil-fuel production and re-start the Keystone pipeline process; both decisions that would be detrimental to the environment.

At the first presidential debate last September, Clinton brought up his wild claims about climate change.

This is how the exchange went down:

CLINTON: Some country is going to be the clean- energy superpower of the 21st century. Donald thinks that climate change is a hoax perpetrated by the Chinese. I think it's real.

TRUMP: I did not. I did not. I do not say that.

CLINTON: I think science is real.

TRUMP: I do not say that.

Trump has since backed away from what he said, calling his words a "joke" and has even denied saying these things altogether. However, over the years Trump hasn't shied away from his skepticism about climate change, and he has referred to it as a hoax many times. A lot of these claims are on his Twitter feed.

This tweet is from January 2014.

"NBC News just called it the great freeze — coldest weather in years. Is our country still spending money on the GLOBAL WARMING HOAX?"

A few days later.

"Snowing in Texas and Louisiana, record setting freezing temperatures throughout the country and beyond. Global warming is an expensive hoax!"

"Give me clean, beautiful and healthy air — not the same old climate change (global warming) bullshit! I am tired of hearing this nonsense."

Last January he told Fox & Friends that climate change was merely a very expensive form of tax.

"A lot of people are making a lot of money. I know much about climate change. I'd be — received environmental awards. And I often joke that this is done for the benefit of China," he said. "Obviously, I joke. But this is done for the benefit of China, because China does not do anything to help climate change. They burn everything you could burn; they couldn't care less. They have very — you know, their standards are nothing. But they — in the meantime, they can undercut us on price. So it's very hard on our business."

In a speech on energy policy in North Dakota last May, Trump referred to "draconian climate rules" and attacked "all the job-destroying Obama executive actions, including the Climate Action Plan."

"President Obama entered the United States into the Paris Climate Accords unilaterally and without the permission of Congress," he said. "This agreement gives foreign bureaucrats control over how much energy we use right here in America."

The fact that the new president of the US has repeatedly disagreed with the science is concerning, not just for the future of climate science, but for everyone that lives on earth. The USA is the second largest emitter of carbon dioxide, so if Trump makes decisions to make the situation even worse, we could all suffer.