>Whether or not it will negatively impact our world insofar that we should try to prevent it: not falsifiable

Could you expand on this? There's a difference between 'hard to show through theory' and 'not falsifiable'.

Here are

http://en.wikipedia.org/wiki/Effects_of_global_warming

If the IPCC's recommendations on CO2 are not followed, which seems likely, we will directly test most of these claims.

As long as you have a definition of 'negatively impact', that can be evaluated objectively, it seems like 'Whether or not it will negatively impact our world insofar that we should try to prevent it' is eminently falsifiable, as there exists an experiment which allows us to see what happens. Expensive experiments, yes, but that's a different issue.

It's not objective, it requires subjective values.

The argument is (generally) made that climate is changing; this will change various peoples' lives in various ways, and therefore must be avoided at all costs.

One rarely if ever sees a consideration of positive outcomes from climate change (and there certainly are some). We need to understand the pros AND cons. And then we need to use our own subjective values to consolidate them into a bottom line.

THEN, we need to understand what needs to be done to avert these eventualities, and what the costs of those efforts will be.

FINALLY, we can compare the costs with the benefits. But because the calculation necessarily included our subjective values of the different factors, it's not falsifiable.

What's concerning is that people conflate the science that the earth is warming with the "non-science" that some catastrophic event is looming on the horizon if we don't stop that warming. The first is a testable hypothesis. The latter, when you consider the complexity of modeling climate and ecology, is at best no different than stock picking. That's why I disagree with the notion that climate skeptics are intellectually insincere in questioning climate change; whether they are right or not, there is a possibility this could be the next eugenics-like pop junk science where we are told we should make sacrifices because of some purported "theory".

Insincere is comparing climate change to eugenics. Eugenics was purely a theory and promoted taking away people's right to have children (or in the worst cases, genocide). Climate change involves hard evidence that the world is warming and demands economic changes to mitigate.

Any policy debate is going to be far more complicated that any testable hypothesis and scepticism is healthy, but your comparison to eugenics is bullshit.

As a global warming noob, I wonder how a controlled environment is simulated to link climate change directly to human activity. Also, how can these claims be tested given that man-induced global warming cannot be repeatedly tested? Is there a formula to calculate the relation of carbon levels to temperature that can be retroactively tested for accuracy? If not, how do we know the degree to which carbon must be curved?