I saw a really interesting documentary on either National Geographic or History Channel a few weeks ago that said that we had only recently (w/in the past 100 years) come out of a "mini" Ice Age. "Mini" is, of course, relative, since 100 years is only a blip in terms of geologic time. Anyway, it seems that, until around 1400 or so, it was warm enough in England that they could produce their own wine but that the climate changed drastically in the late 14th/early 15th centuries. This mini Ice Age therefore lasted 600 years or so, until the late 19th century.
The opinions in the program ran the gamut. Some said that the Ice Age was triggered by sunspot activity. Others said that it was from changes in the earth's magnetic field. Yet others said that it was from unusually high levels volcanic activity during the period. It was so cold in the summer of (I think) 1816 that parts of New England had 2 feet of snow. Yes, IN THE SUMMER.
Regardless, the temperatures started rising in the late 19th/early 20th centuries, decades BEFORE everyone owned a car and more than 100 years AFTER the start of the Industrial Revolution hit Western Europe and North America and more than 50 years after trains started crossing Europe and North America.
The Left keeps telling us that the US is warmer than any time on record. But it is important to remember that a) we have only been the US for 230 years, b) 100+ of those years were during that mini Ice Age and c) that records 230+ years ago were not exactly as accurate as they are now.
So, yes, temperatures are rising, and yes, humans may have something to do with it. But it cannot be all our fault because, if you take all of history into account (and Liberals are way too self-absorbed to think about anything other than the here and now), you'll see that temperatures have fluctuated wildly over the years. Everyone except for those who deny the existence of the fossil record knows that the continents were once in different places on the globe than they are now and that places on the earth that are now landlocked used to be under water. In 5+ billion years, the earth has changed a lot.
The primary Little Ice Age occurred between about the mid-1400s to the mid-1800s, and the main cause was reduced solar activity (indicated by a very low number of sunspots observed on the Sun). The episode in 1816 of which you speak was caused by the huge eruption of Mt. Tambora, which caused a strong cooling effect in the next 2-3 subsequent years. This compounded the cooler temperatures of the Little Ice Age.
Regardless, the temperatures started rising in the late 19th/early 20th centuries, decades BEFORE everyone owned a car and more than 100 years AFTER the start of the Industrial Revolution hit Western Europe and North America and more than 50 years after trains started crossing Europe and North America.
Climate and global temperature do not necessarily respond linearly and immediately to changes in radiative forcing. Also, the oceans have taken up some of the excess heat produced in the Earth system over the past 150 years or so, postponing some of the temperature rise.
But it is important to remember that a) we have only been the US for 230 years, b) 100+ of those years were during that mini Ice Age and c) that records 230+ years ago were not exactly as accurate as they are now.
The "instrumental period" is generally considered to start about 1890.