Only you, Algore, and Heil Heidi believ that. The climate has always warmed and cooled, warmend and cooled. Just in the 20th century, it cooled until about 1910, warmed until roughly 1940, cooled until the 1970s, warmed until the end of the century. The temperature has not gone up in several years. Your data simply doesn't hold up.
Right now, we appear to be in a warm cycle. But it's been warmer than today. There was a major warming in the Middle Ages, followed by a major cooling during the Renaissance. Were those anthropogenic? The medieval warm period was, according to most reports, at least as warm as the current era. We know that the Vikings farmed Greenland and wine was made in Nova Scotia. Try that today.
The temperature has gone up less than a degree in a century. Futhermore, most of that happened prior to 1940 and apparently none in the past few years, as the temperature is what it was about 7 years ago.
Anthropogenic theory is largely based on the hockey-stick model, which has been proven false and on computer projections that have been proven to be wrong. That's why people like Algore and Heil Heidi have to work overtime to suppress any discussion of the data on the issue and to ge critics of their opinions defunded. That's the only way they can establish their case.
Now consider this: CO2 is considered a greenhouse gas. Trees and other plants take in CO2, so planting more trees should reduce the CO2 levels in the atmosphere. There are more threes than ever before (thanks in large part to the paper companies), yet the Earth appears to be in a warming cycle.
Why does the climate response to increased radiative forcing have to be linear? 1998 was the year of a monstrous El Nino -- and El Nino years are always warmer-than-normal years. 2005 was ranked ahead of 1998 by one group (GISS) and just less than 1998 by NOAA. And there was no El Nino in 2005, so it was a "normal" year. That means that the underlying trend is upward.
But it's been warmer than today.
Nothing quantitative/comparative can be said regarding global temperatures more than 400 years ago.
There was a major warming in the Middle Ages, followed by a major cooling during the Renaissance. Were those anthropogenic?
The actual sense of this was that the "Medieval Warm Period" was about as warm as now, and the Little Ice Age was colder. The LIA appears to have been colder due to lower solar activity.
Anthropogenic theory is largely based on the hockey-stick model, which has been proven false and on computer projections that have been proven to be wrong.
That's not accurate. The "hockey stick" is a paleoclimate temperature analysis. Anthropogenic GHG warming is based on the fact that atmospheric CO2 absorbs infrared radiation, and increasing concentrations absorb more infrared radiation, altering Earth's radiative balance.
Trees and other plants take in CO2, so planting more trees should reduce the CO2 levels in the atmosphere. There are more threes than ever before (thanks in large part to the paper companies), yet the Earth appears to be in a warming cycle.
The Mauna Loa (Keeling) CO2 curve shows the uptake of CO2 seasonally by northern forests. The curve shows a continuing upward trend, indicating that CO2 sinks are insufficient to fully absorb the CO2 added to the atmosphere by fossil fuel combustion.