Like gravity, climate change isn't always obvious, but its forces on Earth are increasingly clear . Yet, more than half of America's 115th Congress are climate change deniers, according to a Motherboard survey of their personal testimonies and voting records.

What would you think if your government didn't believe in gravity? If your senator alleged that, because they couldn't see it, perhaps it didn't exist. To many, this might seem absurd—the science is enough to know that it's real.

Fast-forward three decades, and the United States is facing one of its most anti-science Congresses in history. Many members of the Senate and House of Representatives have gone on-record to denounce climate change as a hoax. Others have proven through their votes that regulating greenhouse gas emissions is not a priority. And still, some state representatives claim to believe in human-made climate change, but consistently support policies that would erode initiatives to combat it.

Almost 30 years ago, a NASA scientist named James Hansen pleaded with Congress, under the Reagan Administration, to accept the evidence and do something about it. "It is already happening now," Hansen said before a Congressional committee in 1988.

The majority of climate scientists—at least 97 percent —agree that climate change is happening, and is a consequence of human activity. Government and independent climate scientists alike have published abundant evidence showing our impact on Earth's climate. Meanwhile, task forces like the United Nations' Intergovernmental Panel on Climate Change (IPCC), have underscored the necessity of significantly reducing our global emissions.

For the purpose of this survey, we defined climate change deniers as those who deny the existence of anthropogenic, or human-made, climate change. Senators and representatives who called themselves "skeptics" were also included, because enough empirical evidence exists for them to make an informed decision on whether people are influencing the climate. To the argument that voting against climate change bills is not the same as denying it exists: the many species , ecosystems, and people already seeing its effects can no longer wait for Congress to debate the merits of addressing climate change right now.

Curiously, states that are most vulnerable to climate change are not immune to a leadership of denial. In Florida, for example, where sea levels are carving away parts of its coastline, 14 out of 27 Representatives are climate change deniers. Even in California, where climate change is linked to, or at least exacerbates, periods of extreme drought, 15 out of 53 Representatives are climate change deniers.

Deniers tend to use the same (scientifically debunk-able) reasoning for their beliefs. Explanations for recent climatic shifts include solar activity, corruption among scientists, Al Gore, and the discerning will of God.

But the excuse most frequently touted was that Earth's climate has always been changing. It's partly true; the geological record tells us our planet has gone through several glacial and interglacial periods, most recently between 120,000 and 11,500 years ago. Experts at the National Oceanic and Atmospheric Administration, for example, believe that fluctuations in solar radiation due to Earth's varied orbit are one cause for these changes. To be clear, the mechanisms behind these cycles are established science. And instead of entering a gradual cooling period, which we should be right now, we're actually getting warmer, due to human activity.

Deniers tend to use the same (scientifically debunk-able) reasoning for their beliefs.

In regard to life on Earth, ancient widespread die-offs, such as the Permian-Triassic extinction that killed 70 percent of terrestrial species, have been linked to peaks in greenhouse gases and extreme warming. Scientists aren't saying that climate change definitely caused these extinction events, but they could act as much-needed harbingers for current times.