America needs a leader who understands the danger climate change poses, and Donald Trump definitely does not, writes Aishwarya Kumar.

Ellen DeGeneres posted on Facebook: "I texted Leonardo DiCaprio to come be on my show, and he showed up three hours later."

The post popped up with the hashtag Before the Flood.

It was about National Geographic’s 100-minute documentary – which is available for free on Nat Geo’s Facebook page and on their channels - about climate change.

DiCaprio had been working on the project for the last three years.

He was on Ellen’s show for less than two minutes, but there was an urgency in his eyes and voice that resonated with DeGeneres and the fans in the studio.

The same urgency is palpable throughout the documentary.

Leo is no scientist. He is like any other human being who is trying to understand the significance of climate change and the means to mitigate it. There was almost a childlike approach Leo look to understanding the subject. He understands that in order for this documentary to reach the common man, he needs to explain it in simple terms.

Not for a second was I bored while watching it. Throughout, I felt like I was learning and walking the path with him when he was in Greenland, China and later in India. There was the scientific world of climate change, there was him and then there was me. And I felt like he was acting as the middleman to help me understand the concept better.

The documentary starts off with journalists and scientists being cynical about Leo's role as the UN's messenger on climate change.

Di Caprio was all too aware of his lack of knowledge on the subject.

He says, “The more I try to learn about it, the more I realise I know so very little about it.”

But to me that felt earnest. He wanted to try his best to help the earth in whatever way he could.

Every time he says, “wow, this is so cool!” or “This is unbelievable,” you think those things with him.

People still think of climate change as an abstract term and that it is not the most pressing issue, but I expect that this film will be very effective in making even those non-believers question their attitude.

The main takeaway from the documentary for me was this – the earth's temperature has risen 0.85 degrees Celsius between 1880 and 2012. The coral reefs will begin to die even before the it reaches 2 degrees Celsius. But the prediction says that the earth will see a rise in temperature of 1.5 to 2 degrees Celsius. There is nothing that can be done about it. At 3 degrees Celsius, the tipping point occurs.

So the main goal now is to make sure the temperature doesn’t raise by more than 2 degrees Celsius.

Human beings are the reason behind climate change and if we don’t do anything about it, it is only a matter of time before the tipping point will occur. It was incredible to see how even a simple change in diet from beef to chicken will reduce emissions of fossil fuel (i.e. methane from raising and feeding cattle).

What was strikingly ironic and painful was when Di Caprio mentioned that they had to relocate the entire set of The Revenant from Canada to Argentina mid-shooting because the ice in Canada had melted away suddenly.

Throughout the documentary, I kept going to back to one question: There are scientists and people like Di Caprio who are working day and night to make people aware of climate change and then there is US presidential candidate Donald Trump, who says climate change is a hoax created by the Chinese government. What?

It is like when Cornelius Fudge refused to accept the fact that Lord Voldemort was back in book five of Harry Potter because he knew he wouldn’t be able to do squat to find a solution to put him away for good.

And then there are people like Marco Rubio, who says he “does not believe that human activities are causing these dramatic changes to climate the way these scienctists are portraying it.”

Are you saying solid proof is not enough for you to believe in something?

From meetings with Barack Obama to Pope Francis, Di Caprio travelled extensively to preach his message and search for solutions. He says he doesn’t know if this is doable, if earth is savable. But his raw passion and optimism are traits needed in the kind of leader the US and the world needs to tackle this very pressing issue head on.

With Election Day coming up in less than three days, America needs a leader who understands the danger climate change poses. If Trump becomes the next president, that essentially means we are kissing the earth as we know it goodbye.

Because Trump will crack jokes about heat and climate change like it is nothing more than a fictitious villain from a storybook.

If Voldemort were real, even he would tell you that climate change is real and is not going away until we do something about it.

Catch the full documentary on Nat Geo’s Facebook page and their YouTube channel.

* Aishwarya Kumar is a student at Northwestern University in Chicago and part of the Medill News Service. She is currently an intern at The Star newspaper.

** The views expressed here do not necessarily reflect those of Independent Media.