At one of the GOP debates earlier this year, a republican (I cannot remember which) blasted republicans for denying climate change; however, that doesn't mean he will actively contribute to help with global warming. I don't think Republicans can avoid this common sense for much longer, as it is one of the most pressing issues facing the world today.
I think that a GOP Republican candidate will only negatively impact the ecological and environmental issues that the government should really be putting more time and effort into. They don't even touch upon them much in their debates or platforms because they really don't even care about the issue at all.
Unfortunately for some reason the GOP base has decided to skew what all of science is clearly articulating: global warming is real and it is here and getting worse. In order to appease this base they are ignoring and in some instances down right denying that global warming is even a problem, and in turn discouraging any attempts to reverse the effects. This sets a dangerous precedence if any of them become president of the United states, as we are the country that leads and encourages all other countries to do the right thing. If they are in power and make no attempt to lower emissions in the states and around the world the effects can be catastrophic, as we are quickly running out of time.
Republicans may placate to the "naysayers" but they will not reverse current laws or undermine improvements in protecting our environment. Most of it is just talk to allow a certain portion of the population remain in denial. To reverse the many changes and regulations would take more than an executive action or a new law. They could only allow the current corporate powers take advantage of blind eyes or neglectful government looking over the shoulder to allow a lack of progress for the environment. Despite that, such an act would be illegal. The Republicans would have to make a law to rollback thousands of lines of regulations and then everyone would have to sift through and figure out which is which. The Democrats rolled out healthcare, and it took everyone five months and some to figure out what was in it.