Thomas Jefferson on Global Warming

Former U. S. President Thomas Jefferson kept records of wind, precipitation and temperature at his home in Monticello, Virginia from 1776 to 1818. He was intent upon collecting data (even ordering  James Madison continue to collect it when he was travelling) to derive new weather theories, as he felt meteorology was one of the least-advanced sciences during his lifetime.

Thomas Jefferson, Notes on Virginia I, vol.3 (Correspondence 1780-1782) (paragraph 1205):

“A change in our climate however is taking place very sensibly. Both heats and colds are becoming much more moderate within the memory even of the middle-aged. Snows are less frequent and less deep. They do not often lie, below the mountains, more than one, two, or three days, and very rarely a week. They are remembered to have been formerly frequent, deep, and of long continuance.

The elderly inform me the earth used to be covered with snow about three months in every year. The rivers, which then seldom failed to freeze over in the course of the winter, scarcely ever do so now. This change has produced an unfortunate fluctuation between heat and cold, in the spring of the year, which is very fatal to fruits. From the year 1741 to 1769, an interval of twenty-eight years, there was no instance of fruit killed by the frost in the neighbourhood of Monticello. An intense cold, produced by constant snows, kept the buds locked up till the sun could obtain, in the spring of the year, so fixed an ascendency as to dissolve those snows, and protect the buds, during their development, from every danger of returning cold.”

"The accumulated snows of the winter remaining to be dissolved all together in the spring, produced those overflowings of our rivers, so frequent then, and so rare now.”

From Newsmax.com:

In a letter to Philadelphia physician and professor Nathaniel Chapman dated Dec. 11, 1809, nine months after he left the presidency, Jefferson wrote:

“The change which has taken place in our climate is one of those facts which all men of years are sensible of and yet none can prove by regular evidence. They can only appeal to each other’s general observation for the fact."

“I remember that when I was a small boy, say sixty years ago, snows were frequent and deep in every winter, to my knee very often, to my waist sometimes, and that they covered the earth long. And I remember while yet young to have heard from very old men that in their youth the winters had been still colder, with deeper and longer snows. In the year 1772, thirty-seven years ago, we had a snow two feet deep in the Champain parts of this state, and three feet in the counties next below the mountains . . ."

“While I lived at Washington, I kept a Diary, and by recurring to that I observe that from the winter of 1802-03 to that of 1808-09 inclusive, the average fall of snow of the seven winters was only 14½ inches, and that the ground was covered but sixteen days in each winter on average of the whole. The maximum in any one winter during that period was 21 inches fall, and 34 days on the ground, the minimum was 4½ inches fall and two days on the ground . . ."

“Williams in his history of Vermont has an essay on the change in the climate of Europe, Asia and Africa.”

It’s clear, then, that the earth was warming during Jefferson’s time. It’s also clear that the climate change could not be attributed to man’s activities!