Humans have caused atmospheric CO2 levels to rise at unprecedented rates.
Here is a website to help you understand the relationship between temperature and CO2:
http://www.skepticalscience.com/co2-lags-temperature.htm
While the CO2 spikes lag temperature spikes, it is because of the CO2 that temperature increased as is did - once the temperature increases a little the oceans release CO2 which in turn causes the temperature to increase more and more CO2 is released, causing the temperature to increase more. If only Milankovitch cycles were the cause of this - the current climate trends deviate from what should be happening due to natural variations.
H2O has an average residence time in the atmosphere of a little over a week. We can expel huge amounts of H2O into the atmosphere, but it can re-equilibrate itself within two weeks. That being said, we only output a small portion of the atmospheric H2O. By contrast we output a large percentage of the atmospheric CO2 which has a residence time of hundreds of years. In short, H2O being a greenhouse gas is not an important fact at all in this discussion.
The current rates of glacier retreat are not normal. You act like just because something happens on smaller scales that it makes bigger scales normal. They are not equivalent.
