NASA's Climate Change Site has compelling, long term environmental measurements, and scientific analysis. The Key Indicators page is especially eye-opening.
http://www.geocraft.com/WVFossils/PageMill_Images/image277.g...
Age of the Earth: 4.5 Billion years. Time we've had weather satellites up: 30 years. Geologic time, it's cool, wrap your head around it.
Fun fact, C3 plant life dies at 220 ppmv or lower CO2. Wheat, rice, soybean, cotton, tomato, barley, potatoes - all gone. No ifs and buts about that one, photosynthesis ceases. That's how dangerously close we were teetering to extinction, with the world's carbon entrapped underground. Luckily, along comes man to dig up fossilized carbon and free it back into the carbon cycle where it came from...