Hey Mr. Green,
I am getting conflicting data about greenhouse gas affecting global warming. According to Pete Jonker, writing in Waste News, temperatures on Earth rises before carbon dioxide levels do. The average period between the two effects is 800 – 1,300 year. If carbon dioxide levels drive temperatures, why is it we were experiencing reduced temperatures globally in the ’60s and ’70s –Leon in New Orleans, Louisiana
First, let me say it again: Even if global warming were a complete hoax, we should still be burning a helluva lot less fossil fuel. And we were complete idiots to wait for $5-a-gallon gas to remind us of this fact.
Fossil fuel is a precious resource that, despite its many drawbacks, has made life a lot better for billions of people--from ditch diggers to mathematicians--since fossil fuels power backhoes, computers, and so much else.
Yes, it nearly kills me to admit it, but I agree with ol’ Dick Cheney and his greedy pals on one point: We’re going to be dependent on fossil fuel for some time to come. We can’t stop burning it overnight, even if we get what is desperately needed: a massive New Deal-type construction program to develop a clean-energy infrastructure—something like the $300 billion effort proposed by the Apollo Alliance. (I wrote about the powerful effects of New Deal environmental and construction projects in California magazine this month.)
So if we need fossil fuels and we know there is a limited supply, we should be using the smallest amount possible without diminishing our basic quality of life. At the same time, we should recognize that burning more than we need has already produced tangible effects--and not just at the gas pump. Take the auto industry, for example: U.S. workers have lost their jobs in part because the industry chose to invest in SUVs instead of a new generation of fuel-efficient cars. Or the global food crisis: The amount of energy it takes to grow, harvest, and ship food has been a major factor in making basic staples too expensive for poor people around the world.
Now, as to your doubts about global warming. Jonker’s observations, while correct in general, simply don't refute the evidence of human-caused climate change. (I explain why after the jump, so read on.)
No climate scientist would deny that there have always been fluctuations in temperature caused by factors other than carbon dioxide emissions. But they know the damage that changes in temperature and climate—even gradual ones—can cause. They also know that change is now occurring at a more rapid pace, in terms of temperature, sea levels, and glacial melting. Just because there have always been swings in climate doesn't mean that we can shrug off the one occurring right now. If a psychiatrist had a patient whose mood swings caused recurrent homicidal fantasies, he or she wouldn't say, "Well, shucks, historically folks have always had homicidal mood swings" and then refuse to treat the patient. What matters is not whether changes have always taken place, but what harm might result from a specific change at a specific time. It’s not a new revelation that drastic climate fluctuations have wiped out millions of species. The difference is that we human beings simply weren’t around.
Jonker is right in stating that warming precedes carbon emissions by 800 years, but wrong in saying this data proves carbon dioxide doesn't affect climate change. Yes, temperatures do rise for 800 years before CO2 levels rise. But after this, CO2 increases in sync with temperature, and this extra CO2 accelerates the warming. This feedback loop has several multiplier effects: Melting ice caps, for example, reflect solar radiation, which also accelerates warming.
Climatologists concerned about global warming do not claim that CO2 is the sole cause of or even the trigger for global warming, which is what Jonker implies. But they do see it as a serious contributing factor. Climate models suggest that once the CO2 and other greenhouse-gas levels begin to rise, they may account for as much as 40 percent of total warming. Since CO2 is rising so rapidly (thanks to human activity), the intensity of its proven warming ability is amplified.
Jonker's argument gets downright reckless when he implies that carbon dioxide isn’t a problem because it makes up an "underwhelming" .04 percent of the atmosphere. This is like saying that a fatal dose of arsenic makes up an “underwhelming” .04 percent of a serving of potatoes. The percentage means very little. Obviously, what matters is the effect that even a fraction of a percent can have. So the real point is not that there's a low proportion of carbon dioxide in the first place, but that the level of carbon dioxide has increased from 280 to 360 parts per million in our air and that this rise can make a huge difference because of CO2's well-established ability to trap heat.
Jonkers's claim that the cooler 1960s disproves that carbon dioxide is a factor in climate change is actually undercut by the fact that variations in solar radiation can cause temperature shifts. Yes, lower solar radiation can cool things down, and in fact solar radiation decreased in the '60s. But if you look at the graphs of global warming, they zig and zag like any graph does, where you see downward spikes at various points. The general trend in warming, however, is steeply upward. It's kind of like a drunk walking up a steep slope to a bar. He may stumble and stagger downhill, but his general direction is up to that pub on the summit.
The misuse of numbers doesn't stop there. Jonker also implies that we shouldn't worry about carbon dioxide because water vapor accounts for 94 to 95 percent of the Earth's warming capacity. But this is exactly why we should be concerned with CO2 in the feedback loop. As the climate gets hotter, more water evaporates. If the greenhouse effect of carbon dioxide increases the amount of water vapor, it's one more reason to worry about carbon dioxide emissions.
On top of all this, Jonker doesn’t seem at all bummed by the fact that drastic climate change can cause infinitely more havoc than it did 13,000 years ago. At the end of the last Ice Age, vast amounts of ice melted, causing a rise in sea leves that inundated huge amounts of land. Back then the West Coast was 25 miles farther out in the Pacific. Florida was three times bigger. When the human race consisted of small, largely nomadic populations, climate change was obviously nowhere near as destructive as it could be now in an interdependent world with more than 6 billion people. People could simply drift inland when the ocean rose. There were no cities to flood, no threats to food and water supplies, no spread of disease, or any problems on a scale that we face today.
We already know that climate change has been very destructive, even in later preindustrial societies. For example, the onset of what's now called the Little Ice Age, from about 1250 to 1850, was responsible for famine and other problems in Europe (including possibly the spread of the Black Death that wiped out a third of the population). These changes probably came from increased volcanic activity that blocked out solar energy, combined with a reduction in solar radiation caused by a period change in the earth’s orbit. Here, though, the issue was weather too cold to fit the economy and society that had been developed. Such problems apparently weren’t restricted to Europe. Some scholars have correlated wars and uprisings in China with colder climates. The temperature dropped maybe only 2 or 3 degrees Fahrenheit, but the results were catastrophic. The lesson is that once a civilization has been built up, even small changes in climate, in either direction, should probably not be taken lightly.