You know, I don't give a hoot who was farming 1200 years ago in Greenland or anything else. What I can tell is there's less ice at the North Pole and it sure seems warmer around here than when I was a kid. One can also assess rising sea levels fairly easily. So, call me self-centered, but its the here and now I'm concerned with. No, I'm not one of those people who think climate change causes tornados. However, we need to cut emissions and carbon where we can, and let nature recover/take care of the rest so that over the rest of most of our lifetimes the air continually gets cleaner and there's less stress on the planet.
While not being alive in the 1700's unlike some conservative posters out here it seems logical to me that from the industrial revolution on to present day has to have had a hugely negative impact on what we call climate change. That was rightly or wrongly caused by humans, hence we should also strive to put it right. That doesn't mean moving into huts and living off the land, but it means being more and more responsible than not only our 19th century ancestors, but even more than our parents (in most cases).