Climate change can seem like a far-off distant problem. The reality, though, is that climate change is affecting us today. It’s doing this by taking many of the risks we already face naturally—floods and storms, heat and drought—and supersizing or exacerbating them. And the more carbon we produce, the more dangerous the effects will be over the coming decades. Many continue to believe in some misleading myths. Here are the six I hear most frequently.

It’s been warmer before, so it can’t be humans now

It’s true that the world has been warmer before—but that was a long time ago, before this planet was home to more than seven and a half billion people. In the past, when climate changed it was due to natural reasons: changes in energy from the sun; predictable cycles in the earth’s orbit that drive the ice ages and the warm periods in between; and massive, sustained volcanic eruptions that cooled the earth.

Today, scientists have examined each of these “natural suspects,” and they each have an alibi. According to the sun, and natural cycles, and even volcanoes, the earth should be cooling right now, not warming. But by digging up and burning coal, gas, and oil, we’re producing massive amounts of heat-trapping gases. These gases are building up in the atmosphere, wrapping an extra blanket around the planet. That blanket is trapping more and more of the earth’s heat that would otherwise escape to space. And that’s why the planet is running a fever.

Read my responses to all six myths here.