Here’s a short list of things you can choose whether or not to believe in: Santa Claus, God, love at first sight and unicorns.

What defines these as belief issues is that there is no factual evidence arguing for their existence. Notice that climate change did not make this list. Why, you ask? Because climate change is a discussion of factual evidence, not something you can buy into on a whim.

Climate change is happening right now, and it has been for the entirety of our planet’s existence, as evidenced by Antarctic ice cores. I’ll give you a crash course in climatology to help you better understand the past 800,000 years.

In the early 20th century, a man named Milutin Milankovitch described several cyclical changes in the Earth’s relationship to the sun: specifically the tilt of the Earth’s axis, the shape of Earth’s orbit around the sun and the timing of the planet’s solar solstices and equinoxes. As these various parameters change, it affects the amount of energy the planet receives at particular times. The end result is cyclical climate change.

These cycles last 100,000 years on average. Glacial periods, or the colder ‘ice ages’ last approximately 85,000 to 90,000 years of that cycle. The warmer periods in between, called interglacial periods, are much shorter; lasting anywhere from 10,000 to 20,000 years. We’re currently in the tail end of an interglacial, dubbed the Holocene.

Having described a widely accepted model of climate change that has operated long before humans ever evolved, you may ask what makes current climate change different?

Well, several things. First, during periods of global warming in past interglacial periods, temperature has initially risen, triggering a rise in carbon dioxide emissions in response. Today, due to anthropogenic carbon emissions, this relationship has been reversed—rising temperature is lagging behind the rising atmospheric CO2 concentration.

Secondly, we’re moving in the wrong direction. We’re currently 12,000 years into this interglacial period, almost to the point where our climate should swing back into a colder glacial period. At this point in past interglacials, greenhouse gas concentrations in the atmosphere were declining and the planet was gradually cooling down. Right now, however, the planet is warming while greenhouse gas concentrations are rising. In short, we’ve opened a whole new can of worms.

So this is it. Climate change is a fact, a consensus that has been verified by 97 percent of scientists who make up the Intergovernmental Panel on Climate Change. The atmosphere and oceans are warming. Precipitation regimes are changing, causing drought in some places and floods in others. Ice sheets are melting, the ocean is acidifying and ocean-borne storms are gathering strength, hammering coastal cities with dramatic force.

To ignore this fact is ignorant, cowardly and insulting on several different levels. By acknowledging that we have a problem on our hands, we can act to ward off some of the more drastic effects of climate change.

Yet in the U.S., our general population, especially the politicians that represent us, say they don’t believe in climate change. Not acknowledging climate change means you are scoffing at the efforts of over 400,000 people who came to the streets of New York last weekend for the “People’s Climate March.”

To ignore climate change is to completely undermine the importance of last week’s meeting of 125 political leaders in the UN climate summit, where nations made pledges to alter the planet’s current trajectory towards disaster.

Get your head out of the sand. Climate change is scary, but sitting back and letting this train barrel towards destruction is even scarier. Our strength in this situation lies in our numbers, and as a united front, we can demand action from our leaders and take responsibility for our own future.

Kenna Rewcastle is a senior in College Scholars. She can be reached at [email protected].