A recent study looking at atmospheric carbon when combined with a recent summary of global atmospheric temperatures over the past 30 years sharply illustrates this uncertainty. 

Looking first at the temperature map, which was compiled by the University of Alabama in Huntsville using satellite data of atmospheric temperatures over the last three decades, several interesting things pop out.  First, one quickly notices the relative highs that were reached between 2002 and 2007, which believers in the theory of anthropogenic (manmade) global warming (AGW) tend to fixate on.  And likewise it's equally easy to notice the sharp drop and relative lows experienced in 2008, something that AGW disbelievers elect to focus on.

With the new year, the temperature is on the rise again, but as can be seen in the graph it's unclear whether this increase will truly mark a warming rise, or simply another cyclic variation.  There have been approximately 7 cyclic variations over the past three decades, highlighted by the peaks.

Meanwhile, turning to a new study in Nature Geoscience, in 2008 global carbon levels soared 2 percent to record highs of 1.3 tons of carbon per capita per year.  The paper cites increased use of coal in developing nations as the biggest factor, with emissions from oil and deforestation as minor factors.

One of the paper’s lead authors, CSIRO’s Dr Mike Raupach comments, "The current growth in carbon dioxide (CO₂) emissions is closely linked to growth in Gross Domestic Product (GDP).  CO₂ emissions from fossil fuel combustion are estimated to have increased 41 per cent above 1990 levels with emissions continuing to track close to the worst-case scenario of the Intergovernmental Panel on Climate Change (IPCC).  There will be a small downturn in emissions because of the GFC, but anthropogenic emissions growth will resume when the economy recovers unless the global effort to reduce emissions from human activity is accelerated."

The accelerated rate of carbon emissions raised atmospheric levels to 385 parts per million, 38 percent above pre-industrial levels.  Four billion metric tons of carbon were emitted in 2008.

The combination of soaring emissions and the lack of soaring temperatures paints an intriguing puzzle for those in the climatology research community with open minds.  On the one hand, warming may be occurring, albeit more subtly than many AGW advocates claim.  Under this scenario, a gradual upwards climb over many cycles may be noticed, as global carbon increases.  On the other hand, another possibility is that almost no net warming will occur as carbon may need to reach much higher levels before its effects truly kick in.  And a final possibility is that dramatic warming may indeed kick in at sometime in the near future -- despite the fact that it hasn't yet.

Either way, the overall picture leads suggests, for the time being, that scientists question the IPCC's alarming estimates of global temperature increases.  While such increases can not be ruled out, they do not seem to fit the current data, at least from a macro (global) perspective.

With the international community puzzling over expensive climate change legislation, it is important to consider carefully what landmarks by which to gauge "success" amid the uncertainty of cyclic variation.  Furthermore, critics and proponents aside, the wisest approach seems to be to avoid schemes that throw money into the wind, such as carbon trading or carbon sequestration.  Instead, if money from global taxpayers must be spent, it seems much wiser to put it towards projects that could eventually show financial returns and cut emissions, such as fuel efficient cars, clean fission power, improved solar cells, and viable fusion power.