Studies that scientist agree with are rubbered stamped without any scrutiny, while studies that go against the politically correct dogma are torn apart with every lame argument they can come up with. This is particularly true on global warming.
Global warming, in particular, points to a weakness in the peer review process. The only people qualified to review a global warming study are scientists who themselves are involved in global warming studies, and whose funding is dependent upon global warming continuing to be considered a crisis.
Science is now just another kind of prostitution. The scientist is in the business of getting funding grants, and his ability to continue getting grants is dependent upon him giving the results that grant issuers approve of. A peer reviewer risks his own funding if he gives a bad review to a study which his funders approve of.