EVIDENCE: High Levels of CO2
The levels of carbon dioxide in the atmosphere are the highest in 650,000 years. While the amount of CO2 does cycle, since the start of the Industrial Revolution in the late-eighteenth century, the concentration of carbon dioxide in the atmosphere has increased by 40%, up to 387 parts per million. You can still breathe easy — there is still more than enough oxygen in the air. The problem is with global warming. CO2 molecules trap heat in the atmosphere which, in turn, leads to a wide variety of climate change. Most of that new carbon the amount leading to the 40% increase was produced by man-made industry.