2) We know by examining isotopic ratios that the increase in atmospheric CO2 is due almost entirely to human emissions from burning fossil fuels.
http://www.realclimate.org/index.php?p=8...
3) The natural carbon cycle is in balance. Fossil fuel emissions are not part of the natural carbon cycle. When we release carbon which has been stored in fossil fuels for millions of years, that adds extra CO2 which the natural cycle can%26#039;t absorb, so it accumulates in the atmosphere, causing global warming.
http://en.wikipedia.org/wiki/Carbon_cycl...
Natural variability such as volcanos is handled in IPCC FAQ question 9.2:
Can the Warming of the 20th Century
be Explained by Natural Variability?
http://www.gcrio.org/ipcc/ar4/wg1/faq/ar...
There is one major omission however in carbon cycle science, as the accounting is currently practiced:
Q. Should we be concerned with human breathing as a source of CO2?
A. No. While people do exhale carbon dioxide (the rate is approximately 1 kg per day, and it depends strongly on the person%26#039;s activity level), this carbon dioxide includes carbon that was originally taken out of the carbon dioxide in the air by plants through photosynthesis - whether you eat the plants directly or animals that eat the plants. Thus, there is a closed loop, with no net addition to the atmosphere. Of course, the agriculture, food processing, and marketing industries use energy (in many cases based on the combustion of fossil fuels), but their emissions of carbon dioxide are captured in our estimates as emissions from solid, liquid, or gaseous fuels. [RMC]
http://cdiac.esd.ornl.gov/pns/faq.html
The omission is the assumption that people represent a %26quot;closed loop%26quot;. That%26#039;s only true to the extent that you assume that population remains constant. With rapidly increasing world population however, the addition of new crops and land use conversion to support the increase in size of that so-called %26quot;closed loop%26quot; has a definite impact.
Given that the U.N. oversees the IPCC however, it is politically incorrect to attribute that impact directly to population growth (which would reveal developing nations as playing a leading role in global warming). It must be hidden deep in an obscure section such as %26quot;land use changes%26quot;. How does the impact of today%26#039;s 6.6 billion people compare with the 3.7 billion in 1960, the 1.6 billion in 1900 or the 800 million in 1800? The difference is non-negligible and the topic deserves far more discussion than to camouflage it as land use change. In fact, the sharp uptick in warming rate over the last 40 years may essentially boil down to the approximate doubling of world population.
For more detail on the various CO2 emissions sources and natural sinks, look into the U.S. Carbon Cycle Science Program:
%26quot;The U.S. Carbon Cycle Science Program is clarifying the changes, magnitudes and distributions of carbon sources and sinks, the fluxes between the major terrestrial, oceanic and atmospheric carbon reservoirs, and the underlying mechanisms involved including humans, fossil fuel emissions, land use, and climate. Program scientists are now beginning to reveal and quantify some of the intricate complexities and interactions between the Earth’s carbon reservoirs and climate. Ten federal agencies coordinate and support the program activities...%26quot;
http://www.carboncyclescience.gov/
The First State of the Carbon Cycle Report (SOCCR):
Executive Summary:
http://www.climatescience.gov/Library/sa...
While we%26#039;re on the subject of flaws in the 2007 IPCC report, the IPCC also lumps black carbon in with aerosols, which are said to have a net cooling influence. However, the reality is that black carbon has 60% of the warming influence of CO2, and reducing black carbon soot is the fastest and only proven remedy that we have available to us:
Black carbon pollution emerges as major player in global warming - PhysOrg
http://www.physorg.com/news125500721.htm...
Reducing Black Carbon, or Soot, May Be Fastest Strategy
for Slowing Climate Change
http://www.igsd.org/docs/BC%20Briefing%2...
Again however developing nations are primarily implicated (developed nations reduced their particullate air pollution 80% in recent decades), so the U.N. will likely bury that information and continue its clown-like antics, engaging in a lot of finger-pointing at developed nations.
The ultra rich residing in Hong Kong, Beijing, Mumbai and other major cities in developing nations appear to be poised to reap windfall profits from the U.N.%26#039;s reports and proposed policies. I suspect that most U.N. politicians come from those same wealthy families that will benefit greatly from the U.N.%26#039;s seriously flawed and one-sided approach towards the issue. The rest of us are just pawns in their dangerous game of wealth accumulation.
Acknowledging that current global warming has a solid anthropogenic component is no excuse to provide incentives for CO2 emission growth in major CO2 emitters such as China and India, and it is no excuse to ignore underlying factors such as black soot pollution or population growth.
Elementary school math applied to the growth rates in China and India show that Kyoto-style partial solutions are a dangerous and pointless deception, which only delay the eventual global emission reductions that are required.
-
Answer hidden due to its low rating
Some greenhouse gases (such as holocarbons) have no natural source. Analysis of isotopes, which can distinguish among sources of emissions, demonstrates the the majority of the increase in carbon dioxide comes from combustion of fossil fuels. Methane and nitrous oxide increases derive from agricultural practices and the burning of fossil fuels. Scientific American%26#039;s summary of the IPCC report -
Answer hidden due to its low rating
The IPCC report only gives verified science, not what it %26quot;seems%26quot; you read %26quot;somewhere%26quot;.