“This issue is too important to be politicized!” We regularly hear this said in reaction to topics like education or health care, where the future or well being of many people is at stake. The phrase has become a cliché, but it can still be true – especially if we are talking about climate change.

Greenhouse gases generated by human activity (such as burning fossil fuels, agricultural practices, and deforestation) are continuing to get trapped in our atmosphere, raising the overall average temperature on Earth. That “overall average” detail is important; many people confuse climate with weather. This is what famously led Senator Jim Inhofe of Oklahoma to stand on the Senate floor and hold up a snowball as proof of his belief that global warming is a hoax.

Despite the senator’s confusion, global temperatures have in fact been increasing. This is an objectively measurable fact that cannot be disputed, and we are already seeing the consequences: loss of sea ice, rising sea levels, and an increase in extreme weather. The U.S. Global Change Research Program’s National Climate Assessment Report notes, “Declining water supplies, reduced agricultural yields, health impacts in cities due to heat, and flooding and erosion in coastal areas” as well as risks to infrastructure, increased ocean acidity, more wildfires, more insect outbreaks, more tree diseases, and drought.

This is what science tells us, and despite efforts by climate change deniers to make it seem as though the scientific community is split on the issue, the vast majority of scientists agree on these facts. Science is about evidence. Denying the reality of climate change and global warming requires dismissing science and evidence as illegitimate. Since everyone who takes medicine, drives a car, or uses an air conditioner is relying heavily on the discoveries and achievements of science in their daily lives, such an anti-science stance seems poorly thought-out at best, hypocritical at worst.

What has driven people to cling to this state of blindness or dishonesty in the face of global warming’s serious threats to health, well being, stability, and security? Politics. Once an issue has been politicized, evidence no longer matters. Politicized reasoning only runs backwards, to rationalize a predetermined outcome that will not contradict the preferred political ideology.

Worse, in the case of global warming, political ideology has been shaped by the financial interests of wealthy corporations like ExxonMobil, which has spent millions of dollars supporting organizations that question climate change, and recruiting scientists to challenge the evidence and be public spokespeople to dignify climate denial. The Charles Koch foundation has also backed groups that deny climate change, and conservative think tanks like the National Center for Public Policy Research have provided the propaganda and bullet points for deniers to run with.

Let’s be clear: companies like ExxonMobil are not concerned about the truth. Their concern is protecting their profits regardless of the cost to the rest of the world and its inhabitants. Since they cannot admit this publicly, they have to manufacture and market a worldview that depicts science as unreliable, evidence as irrelevant, and environmentalism as a liberal conspiracy.

Unfortunately, much of the public is far too willing to buy what the big energy companies – and the pet politicians and “experts” who do their bidding – are selling. Politics in the United States has become so polarized, so “us and them,” that people no longer consider evidence at all. Instead, they automatically subscribe to whatever their “side” is telling them.

In a TED talk last year, equality advocate Ash Beckham described how this polarization has turned us into knee-jerk drones on the topics that most need us to think carefully:

“Which side are you on? Are you unequivocally and without question antiwar, pro-choice, anti-death penalty, pro-gun regulation, proponent of open borders, and pro-union? Or, are you absolutely and uncompromisingly pro-war, pro-life, pro-death penalty, a believer that the Second Amendment is absolute, anti-immigrant, and pro-business? It’s all or none; you’re with us or against us. That is polarity.”

Once people’s political behavior stops being about reasoned beliefs – or even about self-interest – and starts being about affiliating yourself with left or right, blue- or red-state America, we become easy to manipulate. The other side becomes the enemy and cannot be trusted, much less engaged in the kind of dialogue that might lead to sharing (and hearing) facts and evidence. Poverty and lack of education exacerbate this problem, making people more vulnerable to manipulation by demagogues.

Religious fundamentalism also predisposes people to distrust science, since they may perceive science as threatening to their core beliefs and values. This is how the GOP evolved into a party funded by big business but reliant on a “religious right” base that can be convinced to vote against its own economic and social interests through demonizing the left as liberal, pro-science, and anti-God. Politicians exploit cultural divisions in our society rather than working to heal them.

It is not news that politics can be ugly and destructive, or that this trend seems to be getting worse. In a few decades, however, there will be more than 9 billion humans on Earth. If their impact on the climate is proportionately as great as ours has been, then global damage will not only be irreversible (many scientists believe that we have passed that point already) but completely unmanageable.

“In the end,” Anthony Leiserowitz of the Yale Project on Climate Change Communication told the website Live Science, “the climate system doesn’t care whether you’re a Democrat or a Republican. It’s not like the floods are only going to hit Democrats and not Republicans or that the droughts are going to impact liberal farmers and not conservative ones. In the end, we all will suffer together and in the end, we’ll all have to solve this together.”

In other words, this is one issue that really is too important to be politicized.