Republican U.S. presidential nominee Donald Trump and Democratic U.S. presidential nominee Hillary Clinton speak simultaneously during their first presidential debate at Hofstra University in Hempstead, New York, U.S., September 26, 2016. REUTERS/Rick Wilking

In Monday's debate, less than two minutes were spent discussing the biggest existential threat we face as a nation and globe: climate change. Perhaps it shouldn't come as a surprise, given that the Republican nominee doesn't even believe it exists, even going so far as to call it a "hoax" created by the Chinese. If Donald Trump and the Republican Party won't acknowledge climate change, then we must bring it to the forefront of the debate ourselves.

During my campaign for president, I had the opportunity to visit college campuses all across the country. Without fail, the students I spoke with identified climate change as one of the most--if not, the most--pressing issues facing our nation. On this issue, they're showing Democrats the way.

Climate change isn't just an existential threat, it's also the biggest business opportunity in the last 100 years. Already 81 leading international companies like Apple, Ikea, H&M, and Bank of America have each committed to moving 100% of their energy consumption to renewable power. This is serious sums of money - with some corporations investing billions of dollars to achieve this feat and creating millions of jobs in the process.

We've seen some important steps forward recently. Under the leadership of President Barack Obama, our country has led the world in joining with the largest global economies like China and India to sign the Paris Agreement, the most ambitious, forward-thinking greenhouse gas reduction plan to be enacted.

Now Secretary Hillary Clinton is proposing to go further. She has laid out a bold and comprehensive plan that will generate enough renewable energy to power every single home in America and reduce fossil fuel consumption by one-third.

Republicans like Donald Trump can continue to pretend like climate change is a hoax, but this denial of science (and reality) won't do our country any good. As a Party and nation, we will benefit greatly if we embrace this challenge and view it as an opportunity.

We know that young voters--the future of our country--rank climate change as one of their top priorities, and that they are critical to our success in November. Let's listen to them on this issue and communicate every day about the importance of saving our planet and growing our economy along the way.