No. it isn't. As a scientist I can firmly conclude Global warming is happening, its caused by human activities, and we need to stop it as it contributes to an array of very devastating consequences.
Hold up there a minute mister scientist, where I'm sitting at the moment was buried under a few kilometers of glacier a hundred thousand years ago, and humans didn't contribute a thing to the sequence of events that caused it to melt. We are in a perfectly natural interglacial, something that's happened before. That's not to say human civilisation isn't contributing to climate change but what's up for debate is just how much of a contribution we're making.
Secondly I find the notion that we can just stop the earth's climate from changing quite suspect - it's not stable or in equilibrium and never has been, with a few possible exceptions. A nudge in the wrong direction and we might find ourselvs back in an ice age, and if you think global warming is bad believe me it doesn't hold a candle to global cooling. Maybe we want to warm things up.
Either way the situation is going to change, so it seems as though the best policy would be to preserve as much biodiversity as possible and ready ourselves for flooding and so on. Not anytime soon mind you, even the worst realistic predictions of sea level rise give us centuries before we start to see significant changes. As things stand I can see all fossil fuel energy sources being phased out by the end of this century, and I fully expect to see widespread adoption of electric vehicles within my lifetime, so it's not so bad. Devastation is going to happen and has happened many, many times in the earth's history, long before humanity made an appearance, but we can minimise it this time round.
And even if we stopped all emissions right now, as far as I'm aware the earth will continue to warm anyway, so perhaps the minor effects of a century of declining emissions versus causing economic chaos right now are a pretty good tradeoff.