America's "Founding Fathers" thought they were affecting the climate

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...

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... 

For an explication of why these views were important in European/American relations, see the original article at Public Domain Review.