Here are Dr. Eric’s claims. Dr. Ed disagrees with all of Dr. Eric’s claims. Therefore, these claims will be central in the Climate Clash debate.
Before 1850, CO2 did not exceed Base CO2 during the last 12,000 years. CO2 did not exceed 300 ppm in the last 750,000 years.
Human fossil fuel burning and deforestation, in that order of importance, have caused CO2 to rise monotonically to 35% above Base CO2.
Today, atmospheric CO2 is 392 ppm and increasing at a rate of about 2 ppm per year. At that rate, CO2 in 2020 would become about 414 ppm. Relative to the Base CO2 of 285 prior to the Industrial Revolution, that would constitute an increase of 45%. If the rate of CO2 increase is further increased, due to increased industrial activities in the underdeveloped countries of the world, then the increase by 2020 will be closer to 50%.
If human CO2 emissions stopped abruptly, it will still take thousands of years for CO2 to return to Base CO2.
We are beginning to see the initial effects of AGW warming.
We are already in trouble with 392 ppm CO2 – due to the delayed heating effects of the excess CO2 and because the excess CO2 levels will last much longer than required for that delayed effect to kick in.
Due to our fossil fuel CO2 emissions, the Earth will be hotter in 2010-2020 than in 2000-2010 unless a known cooling effect (such as increased particulate matter from several huge volcanoes like Pinatubo in 1991, for example) happens to overwhelm the warming effect of the GHG’s.
Due to our fossil fuel CO2 emissions, in the absence of cooling effects noted in #7, the Earth will be even hotter in the decade surrounding 2100.
If CO2 reaches 50% above Base CO2, the Earth will be in distinctly more problematic shape than today because of the impending changes that increased CO2 level will cause. By then, physical changes are likely to have already caused great difficulties. For example, it will be increasingly difficult for the world to adjust to our increasing sea levels since we have become accustomed to the present levels that have existed since civilizations first developed along the countless coastlines of the world.
The threat of CO2 at 50% above Base CO2 is more than significant and might set in motion irreversible changes leading to distinctly less human-friendly physical states of our planet.
CO2 is the most important GHG with respect to its effect on AGW because the most powerful GHG, water vapor, acts primarily as a positive feedback to initial warming effect of the other permanent GHG’s, including CO2.