Question 12. What are the Effects of Higher CO2 Levels? [Quorvita]

A. Are there Agricultural Benefits from increased CO2?

NASA reported that 70 percent of the world’s current greening, observed in satellite photos, is due to increased CO2 levels.  The figure on the left shows a relationship between agriculture tonnage produced and CO2 concentration.  Every 1 ppmv increase in CO2 increases food production by enough to feed 3.58 million people for a year.    

B. What do the Laboratory Experiments Show?

All laboratory experiments show a direct increase in plant growth associated with increasing CO2 levels, up to 10,000 ppmv.  The optimum concentration for maximum production appears to be between 1,000 and 2,000 ppmv.  At these levels, Kentucky bluegrass production increased 32%.  Sweetgum trees increased size and weight at concentrations up to 20,000 ppmv. Orchids experienced a two fold increase in plant sugar and starch content after breathing in 1,000 ppmv of CO2

C. Are there Opposing Views on Plant growth and CO2?

Opponents to the benefits of CO2 rely on climate change projections that anticipate famine and drought.  However, previous predictions of famine and droughts have not occurred and are not expected to occur.  Historically, the greatest time on Earth for plant growth occurred when the air was filled with between 2,000 ppmv and 8,000 ppmv of CO2, many of millions of years ago. This is shown by the shaded portions in Figure 5, to the left.  Furthermore, the fact that the Earth now has so much coal, oil shale and crude oil is a further indicator of the vast amounts of plant growth, during that time.  To argue that our modern “elevated” CO2 levels (which are actually 20 times lower than those periods of intense plant growth) are somehow going to cause massive plant destruction, belies history, laboratory tests, and satellite photos.


Higher CO2 concentrations means greater plant growth.  This is supported by satellite photos, laboratory experiments and increased food production.  Every 1 ppmv increase in CO2 increases food production sufficient to feed 3.58 million people for a year.  The vast amounts of coal, shale oil, and crude oil are the direct result of periods in our geologic history when plant growth was at record levels, caused by CO2 concentrations up to 20 times higher than they are today.