Those who deny the reality, human cause, or danger of global warming, don’t always tell outright lies. One of their common tactics is to say what’s technically true, but is also irrelevant, misleading, or more often, both.
An all-too-common example is illustrated by these two panels from a cartoon (you can see the whole cartoon here):
The cartoon is meant to ridicule Sir Paul Nurse (hence the reference to “Sir Paul” and the nurse’s hat). He isn’t a nurse, he’s a nobel-prize-winning geneticist and president of the Royal Society (Britain’s national science academy, as far as I know the oldest and most esteemed such body in the world). The cartoon states that 97% of the CO2 entering the atmosphere is from natural sources, and is clearly meant to imply that the human contribution (a mere 3%) is negligible. The same statement (with the same implication) is presented in this document by Gregg D. Thompson.
While technically correct, the statement is both irrelevant and misleading.
It quite ignores the carbon cycle:
Every year, hundreds of billions of tonnes of CO2 enter the atmosphere from natural sources like the oceans, land plants, and soil. And — the relevant point — hundreds of billions of tonnes of CO2 exit the atmosphere, bound for those same natural sources. Until we started burning fossil fuels, the inflow to and outflow from the atmosphere was in balance. That’s why, for 10,000 years, the atmospheric concentration of CO2 was reasonably stable at about 280 ppmv (parts per million by volume).
Since the industrial revolution, we’ve been adding CO2 to the atmosphere which has not been balanced by outflows. We’re presently emitting about 30 billion tonnes of CO2 to the air every year. About half of that actually has been leaving the atmosphere for other reservoirs of the carbon cycle, but the other half has remained in the air. Our excess emissions have accumulated over time, raising the atmosphere’s CO2 level.
To make an analogy, suppose you operated a business with cash reserves of $300,000, an annual net income of a million dollars, and annual expenditures of a million dollars. Input balances output, so the net worth of the company, and your cash reserves, remain stable (while providing employment and services to your community). Then you turn the business over to your idiot son-in-law, who continues to take in a million a year while spending the same million as before, plus an additional $30,000 every year on his annual pleasure trip to Las Vegas.
His Vegas vacation is only a small part of the annual budget — a mere 3%. But it’s all of the deficit. Your company is now losing $30,000 every year, and after ten years your entire cash reserve is gone, you must declare bankruptcy, and your employees are looking for new jobs. When you confront your son-in-law, he whines about his vacation being such a small fraction of the annual budget that its’ negligible.
Although our CO2 emissions are only a small part (about 3%) of the total flow into the atmosphere, they account for all of the excess. And that excess has accumulated, so that since the start of the industrial revolution the CO2 concentration in the air has risen from about 280, to about 390, ppmv.
That’s a 40% increase. And it’s all because of us.
Why, then, do those in denial of reality make such statements? I can only imagine two possible reasons.
First, it’s possible that they actually haven’t figured out how irrelevant and misleading their statements are. If that’s the case — if they have the audacity to deny global warming without even bothering to figure out something as straightforward as the carbon cycle and the human impact on atmospheric CO2, then it’s to their dishonor. How dare they try to influence public opinion and policy, without even bothering to learn the basics?
Second, it’s possible that they do know how irrelevant and misleading are their statements. That’s even worse.
Are these the people you want influencing what kind of world we leave to our kids?