Whether climate change is occurring, and especially whether such changes are the result of human activities, are hot topics in the American political landscape. Here's some fuel for the fire:
"...though it is a well-documented fact, it might surprise you to learn that, a far cry from the United States’ recent ambivalence with respect to the modern scientific theory of man-made climate change, the country’s founders were keen observers of climatic trends and might even be counted among the first climate change advocates...For an explication of why these views were important in European/American relations, see the original article at Public Domain Review.
Building on the theories of John Evelyn, John Woodward, Jean-Baptiste Dubos, and David Hume – who all believed that the clearing and cultivation of land in Europe accounted for the temperate climate that had enabled the Enlightenment – the colonists set about arguing that their settlement was causing a gradual increase in temperatures and improvement of the flora and fauna of North America. Hugh Williamson, American politician and a signatory of the Constitutional Convention, believed that “within the last forty or fifty years there has been a very great observable change of climate, that our winters are not so intensely cold, nor our summers so disagreeably warm as they have been,” a fact he attributed to the clearing of forests. “The change of climate which has taken place in North America, has been a matter of constant observation and experience,” wrote Harvard professor Samuel Williams. Benjamin Franklin wrote of the “common Opinion, that the Winters in America are grown milder.” Measurements were as yet inadequate to the task of proving this, he said, but he found the proposed mechanism (i.e. clearing and cultivation) sufficiently persuasive that, even if the winters were not milder already, he could not “but think that in time they may be so.”...
One need hardly belabor the point that the early climate change advocates were wrong [about the climate of that era becoming warmer]. Modern climate reconstructions show there was a brief warming period in New England during the late 1700s, but Jefferson’s and Williams’ measurements predate any actual man-made climate change. Their theories were pre-scientific in the specific sense that they predate a scientific understanding of the greenhouse effect. It is true that the French scientist Edme Mariotte had, as early as 1681, noticed the greenhouse effect, but it was not until the 1760s and 1770s that the first systematic measurements were made, and it would still be another century before anyone imagined that human activities might influence atmospheric composition to such an extent that the climate might be modified by this mechanism. Their pre-scientific theories also led them to believe that a changing climate would necessarily be beneficial, whereas today we are much more aware of the dangers of climate change...
Image (of Jefferson wearing warm furs) source.
This meritless theory was probably behind the disastrous idea that, "rain follows the plow" which led to abuse of the drylands in the American west and Australia.
ReplyDeletehttp://en.wikipedia.org/wiki/Rain_follows_the_plow
I daresay we're working with far more advanced and diverse science to document the fact of anthropogenic climate change. There's no fuel for the nonsensical contemporary debate here, unless you're on the wrong side of modern science and cling to anything obfuscating argument you can.
Quite so. That, along with the theory (endorsed by the government) that planting trees would bring more rain, were disastrous. A few wet years with high grain prices was all that was needed to convince folks to plow up the Buffalo grass and plant like mad. When exceedingly dry years came, the dust bowl tragically resulted.
DeleteWell, they simply did not yet know about the Little Ice Age (LIA) nor about the Maunder Minimum (sunspots) which is definitely connected to the LIA, though no one quite knows how, even now. The LIA ended around 1800, and the climate has been warming ever since, though not always at the same rate. There seems to be a 60-year inclined sine wave superimposed on the warming, and some climate scientists have done research on this, though it is too early to know how it all ties together.
ReplyDeleteThe LIA was not a consistently cold era, however. There were considerable variations - some warm decades and some severely cold ones, throwing farmers into boom times and bust times. But overall the climate WAS warming there at the end of the 1700s and early 1800s. There are wide variations in the dating of the end of the LIA. Some put it at around 1800, and some as late as 1900 or so.
Franklin and those others were not aware of the Maunder Minimum, which was discovered in the later 1800s and not named till still later. Franklin was a VERY good observer of nature, even credited by some with discovering the Gulf Stream.
The 60-year cycle is long enough that every generation is more or less unaware that the ups and downs it sees are repeats of earlier cycles, so each generation is easily fooled into thinking that the warming (or cooling) they are going through is unique.
It is fairly significant that they were pointing at global warming as they saw it, but were not attributing it to CO2, but to LAND USE. Many climate skeptics are not skeptical about warming being caused by changing land use. They call the most obvious modern land use effect "the urban heat island effect." The skeptics assert, basically, that proper adjustments for this heat island effect are not done. I myself decry two aspects of this non-adjustment: First that the adjustment used is far too small, and secondly that the adjustment is a blanket adjustment. I think that each of the thousands of weather station locations should have its specific adjustment, not using one average value. The UHI is in some cases larger than all the warming measured since 1900, so it is a VERY significant factor in climate data assessment.
It is GOOD to see that Franklin and others attributed the warming they saw to land use. At the same time, if warming was significant enough back then, then climate scientists need to include natural variations and land use in their thinking, not assume that all those other factors are unchanging and that only CO2 can possibly be affecting the climate.
Thanks for bringing up the UHI effect. I first stumbled across a reference to it in Michael Crighton's fine book 'State of Fear'. While I disagree with his conclusion that 'there is no global warming that is not natural and cyclical', he does do a very good job of citing his resources for the data he used in the book. And UHI in particular is a factor that is not factored in correctly.
DeleteNo matter what the conclusion on global warming/climate change may turn out to be, the research needs to account for EVERY variable as best we can if we're going to get the correct result. And we're not there yet.