If they could prove what caused the Medieval warming period and the Little Ice Age of the 1800s and say that those causes are not happening now, that would improve the standing of their anthropogenic global warming theory. Instead they tried to cover up the existence of those historic examples of pre-industrialization climate variations which just makes the rest of their theory that much weaker. If your model doesn’t accurately predict the present or the past with data from further in the past, they how can it be relied on to predict the future?
January 26, 1989
U.S. Data Since 1895 Fail To Show Warming Trend
By PHILIP SHABECOFF, Special to the New York Times
Correction Appended
WASHINGTON, Jan. 25 After examining climate data extending back nearly 100 years, a team of Government scientists has concluded that there has been no significant change in average temperatures or rainfall in the United States over that entire period.
While the nation’s weather in individual years or even for periods of years has been hotter or cooler and drier or wetter than in other periods, the new study shows that over the last century there has been no trend in one direction or another.
The study, made by scientists for the National Oceanic and Atmospheric Administration was published in the current issue of Geophysical Research Letters. It is based on temperature and precipitation readings taken at weather stations around the country from 1895 to 1987.
from: www.nytimes.com/1989/01/26/us/us-data-since-1895-fail-to-show-warming-trend.html?pagewanted=1&pagewanted=print