Co2: Good or bad? Nobody knows.

The continued emission of large quantities of Co2 into our Earth’s atmosphere is contributing to the greenhouse effect and threatens to destroy life on this planet. Or does it?
Co2 is plant food, and carbon is the basis of all life on this planet. Having more Co2 in the atmosphere can only be a good thing which will encourage plant growth and therefore food production and everybody will live happily ever after. There is absolutely no credible scientific evidence for the greenhouse theory.
Which of the above are true? Green campaigners are quick to discredit anybody who challenges the greenhouse effect, and most politicians and most of the popular media also fully subscribe to the greenhouse theory. You have to be brave these days to do otherwise. But during the past year we have witnessed a growing body of credible evidence which raises serious challenges to the commonly accepted Co2 / greenhouse science.
Having looked into some of the research results, our conclusion is that today it is quite impossible to draw any firm conclusions on one side or the other. The subject is complex and multi-faceted, and the scientific process of challenge and counter challenge hasn’t reached its full conclusion yet.
A typical debate on the subject might go something like this:
Green (climate change believer): Ice core data proves that Co2 and temperature increases are linked. As we put more Co2 into our atmosphere it heats up. Turn down the thermostat please.
Red (climate change denier): Actually, ice core data shows that Co2 increases after temperatures increase, meaning that global warming causes Co2 increase, not the other way around. The climate is warming through natural variations in our solar orbit, which is in turn causing Co2 to rise. Turn up the thermostat please.
Green: Nice argument, but you can’t justify your SUV that easily. In fact historical records do show that Co2 increases after temperature increases, but only during the first 800 years. During a warming period of about 5,000 years Co2 is increasing ahead of temperature for 5/6ths of that time. Looking at the full set of indicators, what actually happened during that time is that the planet warmed due to varying solar cycles, triggering the initial release of Co2 from the oceans, this release of Co2 then caused even greater warming for the next 4,200 years. What’s happened is that a positive feedback loop has been triggered, similar to what is happening now. Cup of herbal tea please.
Red: (getting technical) Your assumptions are based on obsolete data. Actually, if you look at the analysis of the Vostok ice core you will see that the Co2 / temperature correlation is surprisingly liner (some 8 ppmv for 1°C) and includes shorter glacial / interglacial transitions as well as longer Co2 lags for up to several thousand years. Double espresso please.
Still with us?
Green: Well your statements are based on false assumptions - The correlation being discussed is between CO2 and deuterium/hydrogen isotope ratios in snow (as archived in an ice core). Everybody knows that this is an imperfect measure of temperature. If one corrects the deuterium/hydrogen ratios by taking into consideration the influence of temperature changes at the ocean surface (from which the water that fell as snow originally evaporated),then you will find that the data shows that Co2 does indeed lead temperature increases.
And so on, and so forth.
Now, if one casts any prejudices aside, can you really say (without being a qualified and accomplished climatologist) that one theory or the other might be correct? You can certainly argue the individual points based on your point of view – but what degree of certainty can you have? Any armchair enthusiasts (myself included) who claim to fully understand all the facets of this discussion are deluding themselves.

Perhaps the question of certainty is less important when we are facing a planetary emergency? After all we have been told that we have a window of only 15-20 years to start turning things around. If we risk destroying our home then isn’t it better to act sooner and ask questions later?
Well, there are two major sensitivities that we should consider ahead of any urgent action. Firstly, we should remember that our climate is a system that is still not fully understood. Can we really be sure that reducing the level of Co2 might not also have serious effects on the current climatic balance? Reducing our existing Co2 output is one thing, but adoption of some of the geo-engineering schemes that have been proposed has considerable potential to upset delicate balances. It’s not completely broken yet, so is it wise to try and fix it without having better knowledge of how it works?
Secondly, our global economy is just as sensitive. It has taken government economists years of practice to maintain a global economy of reasonable stability, and it is still subject to occasional wobbles. Economies are systems which are almost as sensitive as our climate, and injecting heavy carbon taxes or restrictive trading schemes could have unknown effects. Remember, carbon based fuels power the engine of our economy and we are talking about reducing the fuel supply. However much they may care about the environment, a major recession will start focusing people’s minds elsewhere. Nothing crushes the soul like poverty.
Let’s be clear that we are not advocating the do nothing approach either. There is more than enough evidence to suggest that we could face some very serious consequences if our climate is out of control. However, we strongly believe that we need to fully workout the science first. The scientific process needs to be accelerated, and conducted unobstructed by political motives. Once we have a more mature level of understanding then we should have a fact based debate about the most sensible cause of action.
What we witness today instead is the pure folly of 20,000 people flying half way around the world (many in private jets) to waste time discussing hypothetical plans based on a poorly understood set of hypotheses. What’s more frightening?
With thanks to RealClimate.



Thanks a lot for this article.
As my layman’s understanding goes, CO2 may or may not have terrifying effects. What we can be sure of however is that in the next 100 years, the weather really will affect all of us - people, agriculture, economies, the lot. As it always has done.
So maybe we should be using all this attention to focus on adaptation?