There's not much point in reducing CO2 unless anthropogenic climate change is real - it has no other negative impacts.*
Pence is the third-highest Republican Congressman in the House, considered a rising star, and appears to simply be stupid. His latest anti-climate change, plus refusal to acknowledge evolution is here. Yglesias has more on him not being very bright here, here (author of the Republican budget plan with no numbers attached to it), and especially here (couldn't understand the economic concept of moral hazard, even when explained to him).
While a party led by stupid people will be easier to beat, it can still cause a lot of damage in the American political system.
*I highly doubt this Republican party genius even knows about ocean acidification, and if he does he just groups it into his climate change skepticism.