Slide 6 of 30
Notes:
This graphic of atmospheric carbon dioxide from the Japanese Climate Center shows the same annual cycle the previous slide, but covering a full ten years. The North Pole is towards the back (left). It also shows how the upward trend is the same all over the world, but the Southern Hemisphere lags the Northern by 2-4 years. This lag arises because the sources of the trend (primarily burning fossil fuel) are predominantly in the North, and it takes a few years for the lower atmosphere (troposphere) to be mixed by the winds. That the source is principally fossil carbon is indicated by the changing isotope ratio (not shown). Some is associated with deforestation and the subsequent oxidation of carbon stored in tree trunks and in the soil.