@ican711nm,
Quote:
http://co2.cms.udel.edu/Increasing_Atmospheric_CO2.htm
Using a combination of modern and historic data, scientists estimate that humans have sent a total of 305 billion metric tons of carbon into the atmosphere since 1751; half of these emissions have occurred since the mid-1970s (Figure 3).
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[PLEASE CLICK ON THE ABOVE LINK TO SEE]
Figure 3: Annual emissions of carbon to the atmosphere from 1751 to 2003 due to anthropogenic (human-caused) sources, primarily from fossil-fuel burning. Plotted using data from CDIAC website (see References section for information).
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Today, atmospheric CO2 levels are 25% greater than at any time in the past 420,000 years. Human activities, primarily the burning of fossil fuels, but also including land-use activities, are responsible for the increase.
There has been considerable research and analysis of increased atmospheric CO2 and global warming; see section on “Climate Change”. About half of the recent emissions are not accumulating in the atmosphere, but are going into the ocean and, to a lesser extent, into soils. These are considered “sinks” in the global carbon budget because they take up atmospheric CO2. The chemistry of the ocean changes as a result of increased CO2 concentrations; this subject is further examined in the section on “Ocean Acidification”.
HOWEVER, significant increases of carbon emissions into the atmosphere didn't start to occur until about 1851. From 1851 until 1982, while the carbon emissions were increasing, average global temperature decreases and increases fluctuated significantly. Those facts
appear to imply that the density of CO2 in the atmosphere has little if any effect on average global temperature.
BUT, if a group of scientists were to limit their attention to only the period 1982 to 1998, the increase in average global temperature and the increase of CO2 in the atmosphere during that period
appear to imply that the increase in CO2 in the atmosphere caused the increase in average global temperature.
http://www.cru.uea.ac.uk/cru/data/temperature/nhshgl.gif