> the role CO2 plays with respect to climate change Is CO2 responsible for about 50% of warming since 1850? Or 100%? or more than 100%, but natural variation

> the role CO2 plays with respect to climate change Is CO2 responsible for about 50% of warming since 1850? Or 100%? or more than 100%, but natural variations have masked part of the warming we would have seen? > whether global warming is a problem or a benefit Is the warming we've had since 1850 primarily a problem or a benefit (hint: most lay people would say problem, but it has been overwhelmingly beneficial).