The chart below is from Watts Up With That.  It shows the prediction made by NASA scientist James Hansen in 1988 regarding the rise in global temperatures he believed would be associated with, and proportional to, the rise in CO₂ emissions.  The blue line represents the increase in global temperature if emissions rose 1.5%, the green line if there were a constant increase in CO₂, and the red line if CO₂ emissions remained constant.  The black line is the actual global temperature increase.  Not shown on the chart is the actual increase of CO₂ emission, which was 2.5%.

If Hansen and his group were correct the temperature increase should been even more than that predicted by the blue line.  Instead it was less than predicted by the red line.  Thus, Hansen’s predictions were off by at least 150%.

Good science enables scientists to make predictions.  If the science is sound the predictions are realized.  For example, science tells us that water freezes at 32 degrees F (zero degrees C), and that water expands as it freezes.   Thus, we can predict under what conditions our pipes will freeze and burst. If we leave water pipes exposed to the elements on a night when temperatures fall below 32 degrees and our pipes don’t freeze or burst, we would question the science.

The alarmists for so-called man-made global warming keep making predictions that keep failing. We should therefore question whether what they are doing is science at all, or if it is pseudo intellectual flimflam.  We may be justified in concluding that what they are up to is not science at all but some mixture of religion and politics.

Hansen’s predictions failed in supporting his theory of man-made global warming, but succeeded in showing that there is little or no correlation between increased CO₂ emissions and increases in global temperature.

None of this means there is no effect on earth’s temperature from green house gases.  In fact, the most important green house gas is water vapor, over which humans have no control whatsoever. Water vapor is such an important green house gas because it virtually enables life on earth to exist. Without it earth’s surface temperature would be similar that of the moon*, which is about 260 degrees Fahrenheit on the sun side and a freezing minus 280 degrees Fahrenheit on the dark side.  We know a little of that phenomenon because our coldest nights in winter occur when the sky is clear of all cloud cover.

*Not quite the same since earth has an atmosphere which the moon lacks.  But is an atmosphere possible without water and water vapor?  I don’t know.