Ok.... the atmosphere is made up of many parts of which CO2 is a very very small part. .04% or 397 ppm to be more specific. By contrast H2O is 2.5% of the atmosphere or 25,000 ppm. H20 is also a so called greenhouse gas because it can absorb IR. Ergo water causes warming.
So here we are with two supposedly evil components of our atmosphere. CO2 that stuff we exhale, yeah the stuff plants use as food to get energy to grow, and H20 that stuff you see all over the place that makes us call this the water planet.
Hmm... should we really be afraid of common components of our atmosphere? Do you really believe the end is nigh because of a small increase in composition for one very small non-toxic portion of our atmosphere? Granted if we kill all the plants and no longer have a natural system for converting CO2 to sugars... well then we might need to stop burping.
It's not the absolute value of CO2 that matters, but the percentage increase, i.e.30-40% depending on whose numbers you use. Any increase heat because of that would also increase the amount of H2O in the atmosphere, furthering increasing the warming trend. That's called a "positive feedback" in the trade. Look it up before posting again, so you won't look so foolish,.