Almost says the whole lot there, but there is much more in the paper.
This study looks at the positive environmental effects of carbon dioxide (CO2) emissions, a topic which has been well established in the scientific literature but which is far too often ignored in the current discussions about climate change policy.
All life is carbon based and the primary source of this carbon is the CO2 in the global atmosphere.
As recently as 18,000 years ago, at the height of the most recent major glaciation, CO2 dipped to its lowest level in recorded history at 180 ppm, low enough to stunt plant growth. This is only 30 ppm above a level that would result in the death of plants due to CO2 starvation.
It is calculated that if the decline in CO2 levels were to continue at the same rate as it has over the past 140 million years, life on Earth would begin to die as soon as two million years from now and would slowly perish almost entirely as carbon continued to be lost to the deep ocean sediments.
The combustion of fossil fuels for energy to power human civilization has reversed the downward trend in CO2 and promises to bring it back to levels that are likely to foster a considerable increase in the growth rate and biomass of plants, including food crops and trees.
Human emissions of CO2 have restored a balance to the global carbon cycle, thereby ensuring the long-term continuation of life on Earth.
This extremely positive aspect of human CO2 emissions must be weighed against the unproven hypothesis that human CO2 emissions will cause a catastrophic warming of the climate in coming years.
The one-sided political treatment of CO2 as a pollutant that should be radically reduced must be corrected in light of the indisputable scientific evidence that it is essential to life on Earth.
| Graph of global temperature and atmospheric CO2 concentration over the past 600 million years. |
Note both temperature and CO2 are lower today than they have been during most of the era of
modern life on Earth since the Cambrian Period.
| Reconstructed Greenland mean temperature anomalies (top) and |
Antarctic CO2 concentration (bottom).
CO2 is essential for life, and twice in the history of modern life there have been periods of steep decline in the concentration of CO2 in the global atmosphere. If this decline were to have continued at the same rate into the future, CO2 would eventually fall to levels insufficient to support plant life, possibly in less than two million years. More worrisome is the possibility in the nearer future that during a future glaciation, CO2 may fall to 180 ppm or lower, thus greatly reducing the growth of food crops and other plants. Human CO2 emissions have staved off this possibility so that at least during a period of glaciation, CO2 would be high enough to maintain a productive agricultural industry.