Hi. I read an article by James Fallows in The Atlantic with the above title. I thought that Fallows, first of all, gave a good summary of the basic facts of climate change--that part is given below. Second, he presents a convincing case for the necessity of finding better ways to use coal if we are ever to get to a clean-energy future and avoid disastrously warming the planet, without cutting back our energy use to pre-industrial levels. Coal is decidedly unsexy, but I think he nails the necessity of continuing to use it as our main energy option. http://www.theatlantic.com/magazine/arc ... re/8307/2/

Try to visualize what one ton of carbon looks like. Now try to visualize 37 billion of these. It seems a very slight chance that this amount would not be affecting climate.

37 Billion Tons

Let’s review the basics. This material will be elementary for some readers and controversial for a few others, but laying it out helps clarify the problem to be solved and the real options from which to choose. Also, the quantities and numbers involved here are so vast—the standard unit in discussing carbon-dioxide emissions is the gigaton, or 1 billion metric tons—that it helps to have some indicators of scale.

All human activity together puts roughly 37 billion tons (37 gigatons) of carbon dioxide into the atmosphere each year. That number has been rising, as the world’s population grows and the number of cars, factories, and power plants increases. Twenty years ago, it was less than 25 billion tons. Twenty years from now, it could well be 50 billion tons. Carbon dioxide is not the only greenhouse gas—that is, a substance that affects the atmosphere’s ability to absorb and emit heat, so that a growing portion of the sun’s energy is trapped to warm the planet rather than radiating back into space. Methane, nitrous oxide, aerosols, and other emissions play a major role, and ton per ton can be more powerful in greenhouse effect. But the focus is on carbon dioxide because we produce so much of it, and because its effects are so long-lasting.

Carbon dioxide added to the atmosphere persists for many decades, even centuries—unlike methane, which can disperse within a single decade. This means that when more carbon dioxide is emitted than natural systems absorb, the concentration in the atmosphere continually goes up. Before James Watt invented the steam engine in the late 1700s—that is, before human societies had much incentive to burn coal and later oil in large quantities—the concentration of carbon dioxide in the atmosphere was around 280 parts per million, or ppm (meaning 280 carbon-dioxide molecules per million molecules of “dried air,” or air with the water removed). It is thought to have fluctuated between about 180 and 280 ppm through the previous 800,000 years. By 1900, as Europe and North America were industrializing, it had reached about 300 ppm.

Now the carbon-dioxide concentration is at or above 390 ppm, which is probably the highest level in many millions of years. “We know that the last time CO2 was sustained at this level, much of the Greenland and West Antarctic ice sheets were not there,” Michael Mann, a climate scientist at Penn State, told me. Because of the 37 billion annual tons of carbon-dioxide emissions, the atmospheric carbon-dioxide level continues to go up by about two ppm a year. For perspective: by the time today’s sixth-graders finish high school, the world carbon-dioxide level will probably have passed 400 ppm, and by the time most of them are starting families, it will have entered the 420s.

Have we so far come across anything that is “controversial”? No: such political controversy as exists mainly concerns the exact connection between rising carbon-dioxide levels and future climate change, and how harmful (and to whom) that change would be. That the atmospheric carbon-dioxide level is rapidly going up, and that recent years have been on average the warmest in recorded history, no one bothers to dispute. And in any case, all parties to the negotiations I’m describing, including the heads of the major coal-mining and electric-power utilities in the United States and China, accept as settled fact that greenhouse-gas emissions are an emergency they must confront, because of the likely disruptive effects on the world’s climate. At a U.S.-China environmental conference this summer in San Francisco, I heard one utility-company official after another testify, confession-meeting style, about the vast extent of their current emissions and their need to reform.

The main uncertainties involve what might happen as carbon-dioxide levels reach 450 ppm and above. In particular, the question is how and when “positive feedback” loops would kick in, so that the hotter things get, the faster they will get even hotter. The main way this would happen would be through melting of the polar ice sheets, which would mean less white ice surface to reflect the sun’s heat, and more blue water surface to absorb it. Similarly, the vast Arctic permafrost areas could have a positive-feedback effect as they thaw. They are essentially frozen peat bogs, which contain huge amounts of methane. As they began to melt, they would release their methane, which in turn could trigger even faster melting and more methane release.

“The reality of it is that in many cases, there may not be any fixed threshold for ‘irreversible’ change,” Michael Mann told me. “What we have with rising CO2 levels in general is a dramatically increasing probability of serious and deleterious change in our climate.” He went down the list: more frequent, severe, and sustained heat waves, like those that affected Russia and the United States this summer; more frequent and destructive hurricanes and floods; more frequent droughts, like the “thousand-year drought” that has devastated Australian agriculture; and altered patterns of the El Niño phenomenon, which will change rainfall patterns in the Americas. In other cases, he said, there could be important thresholds. For example, the possibility of dramatic rises in ocean levels, which could affect the habitability of New York, London, Shanghai, Miami, the entire Netherlands, and many other modern conurbations, along with coastal areas in India, Bangladesh, and elsewhere. “It would be nice to know where such thresholds are so we can avoid crossing them,” Mann said. “We can’t know that. What we do know for certain is that with each fraction of a degree of warming, the probability of such potentially catastrophic outcomes goes up.”

That’s the big picture. Now come the parts of the background that are somewhat less familiar but bear on the argument that the only real salvation must involve coal.