Global Climate Change - The CO2

So, we have seen that the planet is currently warming, but that it has been gradually warming for thousands of years, in cycles, with cooler intervals in between.  Then, around 8 to 10,000 years ago the cycle stabilised, approximately around the current temperature levels.  The big question is, why did it happen - or put another way, why does our temperature fluctuate in the way that it does?

Let's first investigate whether the culprit could indeed be CO2 - man made or otherwise.  Well, as you can see from the chart below, CO2 levels have definitely varied through history, and from the temperature chart you can also see that temperature has varied more or less in a similar cycle.

Carbon Dioxide Chart Sources:

2001-1958: South Pole Air Flask Data
1958-1220 B.P.: Law Dome, Antarctica
1220 B.P.- 2302 B.P.: Taylor Dome, Antarctica
2302 B.P.- 414k B.P.: Vostok Ice Core Data

Temperature Chart Sources:

2000-1979: Satellite stratospheric data
1979-1871: S. Hemisphere ground temp. data
1871- 422k B.P.: Vostok Ice Core Data

During the last 400,000 years the CO2 levels have gone up and down, between about 180 and 300ppm (parts per million), and the only deviation in that cycle does seem to be that in CY2000 the level stood at 370ppm.  How significant is this information?

Well, the first thing you can see from the chart is that CO2 in our atmosphere has been increasing steadily for the last 18,000 years, long before humans invented motor cars or chimneys.  So, unless you count campfires and intestinal gas, man played no role in the pre-industrial increases.  There's another very significant fact from these two charts, and that is that, although temperature does go up and down in tune with CO2 levels, temperature rise always precedes CO2 rise.  In other words it's quite probable that the increasing temperature is creating more CO2 and not the other way around - or at the very least the two parameters are both being affected by the same driver, just on a slightly different timescale.  On the scale of this chart it is difficult to see the effect, but it is definitely there, and so CO2 level changes cannot be causing the temperature changes.  

Worryingly, Earth's temperature and CO2 levels today have reached levels similar to those in a previous interglacial cycle of 120,000 - 140,000 years ago.  From beginning to end this cycle lasted about 20,000 years and this is known as the Eemian Interglacial Period.   The earth returned to a full-fledged ice age immediately afterward!

But it is clear that human activities do seem to have caused a "spike" in CO2 levels in the last 50 years and we are currently standing at what we are told is a "disastrously high" level, with catastrophic results likely for the planet.  Really?  No, really not.  Even if CO2 was affecting temperature, total human contributions to greenhouse gases account for only about 0.28% of the "greenhouse effect" (see chart below).  Anthropogenic (man-made) carbon dioxide (CO2) comprises about 0.117% of this total, and man-made sources of other gases (methane, nitrous oxide (NOX), other miscellaneous gases) contributes another 0.163%.  A fact which the warmists don't want you to hear is that there is another "gas" which is equally effective as a greenhouse gas, and it is present in vastly greater quantities.  That gas is water vapour!

Approximately 99.72% of the "greenhouse effect" is due to natural causes mostly water vapour and traces of other gases, which we can do nothing at all about.  The simple fact is that eliminating human activity altogether would have little impact on climate change.  There are a number of other factors which we are increasingly becoming aware have an influence on global climate.  They include solar cycles (short and long term), volcanic eruptions, ocean currents, clouds, the eccentricity of the Earth's orbit around the sun, and the galactic environment in which the sun and planets find themselves as the sun orbits the centre of the Milky Way galaxy.  Yes, lots of things - and we are going to examine them in more detail in the following pages.

NOTE: "Human additions" represent such a small percentage of the total Greenhouse Effect (0.28%) that they are barely visible in this "pie chart" at the scale represented.

Comparing greenhouse gases by strict concentration only, the total human component is somewhere between 0.1% and 0.2%, depending on whose numbers you use.  Adjusted for GWP, the total human contribution to Earth's overall greenhouse effect is about 0.28%.

Chart compiled using data provided by the US Department of Energy.

Back to Front Page