Putting aside for the moment the question of whether human industrial CO2 emissions are having an effect on climate, it is quite clear that they are raising atmospheric CO2 levels. As a result, they are having a strong and markedly positive effect on plant growth worldwide. There is no doubt about this. NASA satellite observations taken from orbit since 1958 show that, concurrent with the 19 percent increase in atmospheric CO2 over the past half century, the rate of plant growth in the continental United States has increased by 14 percent. Studies done at Oak Ridge National Lab on forest trees have shown that increasing the carbon dioxide level 50 percent, to the 550 parts per million level projected to prevail at the end of the 21 century, will likely increase photosynthetic productivity by a further 24 percent. This is readily reproducible laboratory science. If CO2 levels are increased, the rate of plant growth will accelerate.