I don't think it's a question of whether or not scientists believe climate is changing. It does and always has and always will. Climate simply isn't static. We've had periods of history when the entire Earth was tropical (and 30 or so degrees hotter than now) and periods where the entire planet was icebound (see also: Snowball Earth) and humans weren't a part of the equation. The question is just how much of the current climate change is natural and how much (if any) is anthropogenic in nature. How much is solar, how much if just the nature of the carbon cycle, how much is air and water current related, how much is due to outgassing and volcanism, how much is a function of plant life to land area, so on and so forth?
The next question is what can humans do to stop our contribution AND maintain our standards of living? We're not giving up cars, electricity, manufacturing, and extracting resources, so what is the solution? Coal, oil, and gas fired power is bad, solar and wind are destructive (and inefficient) and nobody wants nuclear because of scaremongering. Even if some solution is agreed upon, it would be decades before there is some widespread implementation. So now what? And that's before we even get into the politics of climate change and how some see it as an opportunity to raise taxes and/or exert more control over economies.