Why is Earth getting warmer and what does carbon have to do with it?

What does he think about the research of Jon Krosnick suggesting that trust in climate scientists is damaged when climate scientists become advocates of specific calls to action or join an advocacy NGO/environmental organization? See link for background. http://eenews.net/public/Greenwire/2012/07/09/1

Have Mr. Mann address the Urban Heat Island effect that is swallowing up America. UHI indeed has an impact on temps we see now and what our "thermometers" say

Ask him why is the little Ice age and the medieval warming period missing from his graph. Also ask him why the global temperature over the last fifteen years has been flatlining.

If the hockey stick graph is significant, why was the graph was left out of the AR4 report? Will it be included in the AR5 report?

I have seen some say that the tree ring temperature data diverged from actual temperature in the late 20th century. How would you explain that divergence and how do you know that such divergences between tree rings and temperature DID NOT occur in the past, before thermometers? If such divergences had occurred in the past, would not that have hidden past warming periods? How do we know that some past periods did NOT also have divergences and were actually warmer than now? Thanks JK

Is the increase of the human population the main cause of the increase in temperature and what can be done about it if so?

An international team including scientists from Johannes Gutenberg University Mainz (JGU) has published a reconstruction of the climate in northern Europe over the last 2,000 years based on the information provided by tree-rings. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1589.html Was the climate during Roman and Medieval times warmer than today?

Why do you refuse to share your data? Why are you fighting requests for access to your communications relating to your publicly-funded research?