It's the sun, stupid!
Go outside at noon on a cloudless day.
Hold up your arm with your palm perpendicular to the blinding bright spot high in the sky.
Feel the heat on your hand• It's coming from 93 million miles away. Yet it's so powerful it'll eventually burn your flesh.
Even filtered by our atmosphere, even after traveling eight minutes at the speed of light, sunshine is so full of energy it can create life on Earth, turn water to gas and melt polar ice.
But the sun can't cause global warming.
The sun is so distant and so small in our sky we forget how enormous it is -- and what a speck of space dust Earth is. Our home star composes 99.82 percent of the mass of the solar system. The sun's mass is 330,000 times the Earth's mass. About 1 million Earths could fit inside the sun.
The sun is a furnace of nuclear fusion beyond human comprehension. Although just an ordinary star, it produces an incomprehensible 386 billion-billion megawatts of energy per second.
Its also real hot. Its core is a hellish 27 million degrees Fahrenheit. Its surface is 11,000 degrees. Its corona, which extends millions of miles into space, has temperatures of 1.8 million degrees.
But the sun doesn't just bathe our tender planet in light and heat. It also blasts us with an invisible hurricane of high-energy electrons and protons that travel at 1.6 million miles per hour.
This solar wind, which extends past Pluto and constantly changes speed, density, direction and magnetic power, can produce auroras like our Northern Lights and knock out electric power grids on Earth's surface.
But the sun can't be causing global warming.
In fact, if you believe the global warming hysterics, the sun's mighty powers to affect our climate have been eclipsed by man's accelerating greenhouse gas output.
The United Nations' Intergovernmental Panel on Climate Change has been saying the sun is responsible for about 10 percent of the roughly 1 degree-Fahrenheit rise in Earth's average temperature over the last century.
But now a new European study of solar activity concludes the sun's effect on global warming is "negligible." Since 1985, the study shows, such factors as sunspots and solar irradiance are trending away from heating the Earth.
The Royal Society, the United Kingdom's national science academy, pronounced that this new study "comprehensively" disproves claims that the cause of recent global warming is increased solar activity. Humans are to blame. Natch.
Lots of other studies have come to the opposite conclusion, of course.
Going back 10,000 years, a 1998 study found that past periods of global warming coincided nicely with increased sunspot activity, which occur during increases in the sun's brightness and energy output. In 2004, a study by the Max Planck Institute for Solar System Research said Earth was getting hotter because the sun was burning brighter than it had in 1,000 years.
We don't want to get into an ugly debate about the prime cause of global warming. But maybe all those sun-worshipping ancestors of ours were not such dummies after all.
Sure, they lived in caves, thought gods controlled the weather and couldn't even spell SUV. But eons ago they figured out what should still be obvious to every creature on Earth today.
The mighty sun is in charge of what happens on puny Earth -- not humans or their fires.