True. Limestone caves have speleothems because the ground water is slightly acidic due to carbonic acid from dissolved carbon dioxide. The acidic water dissolves the limestone (CaCO3) and deposits it in the cave.
There's a giant underground ocean hidden in the middle of this Chinese desert While studying the amount of carbon dioxide in the desert's air, a team of researchers was surprised to learn that large amounts of the greenhouse gas were disappearing around a region of the desert called the Tarim basin. The most likely explanation, they recently reported in the journal Geophysical Research Letters, is a massive underground ocean that has more water than all five Great Lakes in North America combined. http://finance.yahoo.com/news/surprising-discovery-points-giant-underground-215220972.html
These two data visualizations are from the original paper behind one of the three links at the bottom of timojin's reference in post #3: http://www.nature.com/nclimate/journal/vaop/ncurrent/fig_tab/nclimate2728_F4.html http://www.nature.com/nclimate/journal/vaop/ncurrent/fig_tab/nclimate2728_F2.html They describe some correlations one can use to predict people's 1) awareness and 2) if aware, estimation, of climate change due to AGW. They vary significantly by country. In Norway, for example, almost everybody is aware of climate change and that correlates with education; estimates by the aware of the severity of the threat vary more and that correlates loosely with gender for some reason. In the US estimates of the severity among the aware are best predicted by factors labeled "other". In this context, the role of local temperature perception is very significant.
