Notes: Some 'skeptics' say, "It's arrogant that think that humans could alter earth's climate. We're not that powerful."
But it's happened before. Over two billion years ago, the humble cyanobacteria (aka blue-green algae or "pond scum") radically altered the earth's atmosphere. Before cyanobacteria proliferated throughout the oceans, earth's atmosphere contained very little oxygen. Through photosynthesis, they raised the oxygen level and made animal life possible.
It's a remarkable story. summarized in Scientific American, "The Origin of Oxygen in Earth's Atmosphere:"
"The breathable air we enjoy today originated from tiny organisms, although the details remain lost in geologic time.
It's hard to keep oxygen molecules around. . . because oxygen wants to react; it can form compounds with nearly every other element on the periodic table. So how did Earth end up with an atmosphere made up of roughly 21 percent of the stuff?
The answer is tiny organisms known as cyanobacteria, or blue-green algae. These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen. In fact, all the plants on Earth incorporate symbiotic cyanobacteria (known as chloroplasts) to do their photosynthesis for them down to this day."
Ask yourself: Which is more arrogant? To conclude after six decades of research that we indeed are altering the atmosphere? Or to jump to conclusions -- 'It can't possibly be true' -- without considering the evidence at all?
To assume that one's off-the-cuff intuition, innocent of verifiable knowledge, is a more reliable guide to understanding geophysics than the collective judgment of virtually all the world's top climate scientists, who have devoted their lives to this field and reached their conclusions only after decades of work? To continue to dump thirty billion tons of waste products into the air every year, and just assume -- without even looking closely -- that it can't possibly do any harm?
For a variation, see "Little old us? We're not important enough to alter the planet"