Mark, over the last 800,000 years (before our Industrial, FF Burning, Age) the CO2 level varied by

120 ppm on average...enough to create Ice Ages and Interglacial Ages...in just ~150 yrs the CO2 concentration has increased for the typical high of 300 ppm to 425 ppm...i.e. a Doubling...from the previous MAXIMUM...and the trend (see NOAA data from Mauna Loa) has not stopped its rapid increase.

Since the natural "Sinks" (Oceans and Terrestrial Forests) are being filled, or depleted and CO2 takes many decades, if not hundreds of years to be absorbed...we are in very serious jeopardy already...The sooner we switch away from Fossil Fuel burning for Heat and Power, the better off our Progeny will be.

Note that ~60% of the world's population lives on or very near Ocean coasts...have a little concern for those who will follow us.