Question: Is man made (anthropogenic) effects causing global warming?

A look at the facts seems to imply, No.

-273°C (0°K) is absolute zero, the coldest temperature possible. The background temperature of the universe is -270°C (3°K). The Sun raises the temperature of the Earth to about 12°C. 12°C is the lowest Mean Global Temperature (MGT) over the last 600 million years history of Earth's history (Link). 22°C is the highest MGT over the same period. Since humans were not around for much of this history, the only explanation is the Earth-Sun dynamic keeps the MGT between 12°C – 22°C.

Over the last 2000 years, the MGT has averaged 13.7°C with an extreme MGT variation of ±1.7°C and an average MGT variation of ±0.7°C (Link). Looking at the last 2000 years, the lowest MGT was 12.4°C (or -1.3°C below MGT) during the Little Ice Age (1300-1800). This event was marked by a number of violent volcanoes during this period (Link) and a low average number of sunspots in the last 10,000 years averaging 10 per decade compared to the 10,000 year average of about 25-30 (Link).

Conversely, over the last 2000 years, the highest MGT of 14.3°C (or +0.6°C above the MGT) occurred during the Medieval Period (900-1100) or the so-called Climate Optimum. The event was marked by the average number of sunspots (25-30) in the last 10,000 years (Link).

Both of these extremes must be due to natural effects since manmade effects have been relatively non-existent over last 2000 years (disregarding last 200-300 years as we entered the Industrial Age). Today, the Earth is at 14.1°C (+0.4°C) above the average MGT (Link).

For the sake of giving global warming theorists the most temperature extremes possible in the last 2000 year, we will assume the effects of Sun is making the Earth the coldest in recording history (12°C) even though we are currently averaging 75 Sunspots/Decade (Link).

Therefore, a +2.1°C increase in the MGT is solely due to global warming due to greenhouse gases. The four major greenhouse gases are water vapor, carbon dioxide, methane, and nitrous oxide. Water accounts for about 94% of all greenhouse temperature variations or about 2.0°C (Link). This leaves 0.06°C temperature increase due to CO2 which accounts 3% of greenhouse temperature variations (Link). All other greenhouse gases (N2, O2, CH4, N2O, CFCs, etc) must account for the remaining 0.04°C.

Manmade (anthropogenic) CO2 accounts for about 3.5% whole annual contribution from natural sources (decaying plants, geothermal systems/volcanoes, limestone erosion, forest fires, and respiration from plants and animals (Link). Therefore, 0.0022°C is how much man has contributed to Global Warming. This is the worst case scenario assuming the Sun is only warming the Earth up to 12°C (the lowest MGT over the last 600 million years).

An interesting side note is that methane is about 30 times as potent of a greenhouse gas as CO2 (Link) and is said to be responsible for 15-20% of the greenhouse gas effect and CFCs are likewise postulated to contribute 25% to the greenhouse effect giving validity to the inference that CO2 is only responsible for at most a 0.04°C rise in MGT. Note this does not include water vapor.

For those global warming folks who feel my numbers are in error, I did not account for respiration of humans, which of course puts CO2 back into the atmosphere. True enough, but since the concentration of carbon in living matter (18%) is almost 100 times greater than its concentration in the earth (0.19%) (Link), I, as a human being, am just doing my part to extract carbon from the nonliving environment. Since only about 0.19% is available in nature, I am simply recycling the available carbon.

But what if we keep burning fossil fuels and put all that available carbon back into the atmosphere? Won't that cause a dramatic temperature rise? According to the Global Carbon cycle (Link), fossil fuels account for about 11% of the total available CO2. See (Link).

If all available carbon in fossil fuels was burned today, atmospheric CO2 would go from 0.0375% of the Earth's atmosphere to 0.2761% (2761 ppmv) of the Earth's atmosphere. (I actually used current (2005) CO2 data of 375 ppmv instead of the lower 358 ppmv number or 750 GtC). Looking back into recorded geologic temperatures, this could increase MGT to 16°C to 22°C if we assume a relation. See (Link).

For one, there does not exist a good relation between CO2 levels and MGT, but I will go along (for the moment) that a relationship exists.

Secondly, there exists no possibility of burning all available carbon in one day or several days that would not lead to the complete explosive destruction of the Earth as a consequence. Currently the top ten proven oil reserves by country (for 2005) total 1.0893 trillion barrels of oil (Link). The top consumer countries consume 50.5 million barrels of oil per day (Link) or 18.4 billion barrels per year. Therefore, at current expenditures, it would take 59.1 years to totally burn all proven OIL reserves. Understand, I capitalized OIL for emphasis. But remember the (Link) above. Oil only accounts for 1/10 of all fossil fuels. Therefore, at current consumption, it would take 591 years to burn all available fossil fuels. And I know that consumption (especially in the US) keeps increasing annually so the data is a bit sckewed, but that can be solved easily by using nuclear energy more than we currently do. So much for running out of fossil fuels, but that is another post altogether.

If any relation does exist, it is the relationship that today, both MGT and atmospheric CO2 are their lowest levels today other than approximately 300 million years ago which preceded the largest extinction on Earth. The Permian mass extinction occurred about 248 million years ago and was the greatest mass extinction ever recorded in earth history; even larger than the Ordovician and Devonian (380 million years ago) crises and the better known End Cretaceous extinction that felled the dinosaurs. Ninety to ninety-five percent of marine species were eliminated as a result of this Permian event (Link). If we should be worried about anything it is a mass global cooling.

Both of these mass extinctions are attributable to mass global cooling and not warming. The cooling which caused Permian extinction may very well have been caused by the creation of Pangaea (southern polar ice cap) and volcanic eruptions (blocking out the sun). The Devonian extinction (Link) was undoubtedly caused by a meteorite impact also blocking the Sun's warming energy which seen above accounts for 282°C temperature rise while water vapor, carbon dioxide, and other greenhouse gases combined only account for 2.1°C temperature rise of which anthropogenic CO2 accounts for 0.0022°C. No mass extinctions have ever happened due to increases in temperature.

One last point, the Kyoto Protocol was suppose to curb CO2 emission by about 10% which would drop the increase in temperature by about 0.00022°C by the year 2050. Since coming into effect February 16, 2005, the Kyoto Protocol has cost the world well over $100 billion while the potential temperature saving by the year 2050 so far achieved by Kyoto is less than 0.0012°C. That really does represent about $100K per billionth of one degree allegedly "saved." Guess that means for the bargain price of just $100 trillion we could theoretically lower global mean temperature by about 1°C (Link).

Question: Is man made (anthropogenic) effects causing global warming?

A look at the facts seems to imply, No.

If anything, we should be worried about global cooling. It (in conjunction with the affects of massive meteorite strikes) is responsible for all mass extinctions in the history of Earth, not global warming.