And their coverage was even lousier 100 years ago. But most scientists do seem to accept that it has warmed a little over the last 100 years. If it really has risen one degree, there are no signs of the calamities that are forecast to result from warming. No trend has been seen in destructive storms, floods, or droughts, according to the UN's own Intergovernmental Panel on Climate Change, in the scientific section of the Climate Change 1995 report. Meanwhile disease and famine have diminished.
Computer models are the only source of forecasts of the next century.
Well, we've seen their forecasts over the past 20 years, and they consistently forecast that it should be a lot warmer than it has been. They aren't doing too well. Furthermore, very few of these models get the past few centuries right, without all sorts of finagle factors. Yet these models are the source of the forecasts that tell us we have to pay much more for energy in the future, and cut back energy use radically, to save the planet. It gets better.