If Carbon Dioxide is causing warming to the extent that DiCaprio's rhetoric implies, we passed the "we're screwed" point of no return back in the 70s or 80s.
Let's look at the facts.
- Earth HAS WARMED in the past 200 years by about 0.6 degrees Celcius.
- We have models which suggest CO2 can cause warming.
- We know CO2 is on the rise in Earth's atmosphere, almost certainly from fossil fuels.
- Earth's climate naturally varies about 6 C from warmest to coolest, with abrupt 1-2 degree swings.
- Right now, Earth is quite warm compared to the climactic average, but it isn't at the climactic maximum, either.
So in the end, we wind up with a draw. We know CO2 is changing the atmosphere and oceanic pH. We can quantifiably measure that and correlate quantity into the atmosphere with concentration changes.
We DON'T know if the warming is caused by CO2 or if that is a cause for concern. Real scientists put this thing called "margin of error" in their calculations to discern patterns from background noise. Usually these are removed before laymen see the numbers because media people assume we don't understand what a 95% confidence interval is. Earth's warming is well within the margin of error. Earth's climate has changed faster, even if you limit things to just recorded history.
What that means is up to you.
