1) what do we mean by a tipping point? provide some examples of tipping points mentioned in climate change literature. how likely during this decade are we likely to be impacted by a tipping point?

2) why do we use a computer generated models to study climate change?

3) how would you respond to someone who says that there is no link between humans and elevated levels of co2? give me some hard facts and good statements you would share with a climate denier.

4) i have a colleague in physics (this is true) who believes that global warming is not a reality and says changes in temperatures are linked with sun spots. provide me with a response that i can use when we discuss climate change while having a beer after work.