My apologies too, I was rather abrupt in my initial post.
In recent years, price has directly driven production of shale oil and gas in the US. It has been low enough that new development has not been very economically viable, and existing production has even been turned off or slowed. In that environment, government policy towards new acreage or the lesser-spotted newt has minimal impact, as access to reserves isn't a constraining factor on production.
Environmental policy was actually even less of a factor for us, as we developed to higher standards than the minimums in order to maintain a solid relationship with landowners. It's no good trashing the landscape in line with lax regulations if it upsets the landowners and they deny you access.
Once prices rise high enough that everything is switched back on, and all existing acreage is fully developed, that kind of policy would certainly have a larger share of the impact. I don't think we're at that point but we're certainly getting closer to it.