The Minnesota 100% Campaign (Reader Opinion, March 5) is worthless for slowing down global warming by reducing fossil fuel burning, which reduces carbon dioxide emissions.

The question is: Is Earth's temperature going up because CO2 level is going up? Or, is CO2 going up because Earth's temperature is going up?

Mother Nature's reservoir of CO2 contained in the sea, air and land when compared with man's, is a ratio of 2400 to 1, with the ability to recycle CO2 at a rate that is over 30 times greater than man's emissions rate.

The 40,000 miles of mid-ocean mountain ranges are borderlines of earth's crust plate movement that injects tremendous heat into the ocean, along with volcanic CO2. We now "real-time" monitor about 300 miles of it. Most of the remaining 39,700 miles is unmonitored. Until we get a handle on what this big "tank heater" is doing, we certainly shouldn't be touting man-made global warming, especially since rising water temperature will drive out dissolved CO2 at a higher rate into the atmosphere.

Another "tank heater" is solar energy. The heat capacity of CO2 near the earth's surface is about 23 times less than the sun's 150 watts/square meter heat energy at that point. Now consider that about 97 percent of all CO2 in the atmosphere is made by nature, and 3 percent is man-made. So man's puny 0.195 watts/square-meter drives us into thermal disaster?

About 95 percent of the greenhouse effect comes from water vapor. Only about 0.117 percent effect is due to man-made CO2.

Long before the Industrial Revolution, we had the Medieval Warm Period, then came the Little Ice Age, now another warm up. It's a cyclic thing in which sun, volcanoes and cloud cover are the main climate players-not man.

Phil Drietz