Too good. Here's the current plot of atmospheric CO2 from Mauna Loa:
I'm actually surprised that a steady rise can be seen on such a short-term plot, I've always thought a distinct trend would only be noticeable on decade-long scales. Now I've always thought that the greenhouse effect is more of a blanket effect. Water vapor is like a comforter, thick (abundant) and CO2 is like thinner but very efficient blanket. Methane is like one of those space blankets, very thin, very efficient at trapping heat. Anyway adding CO2 is making the blanket it thicker, and we all know by experience how with some materials even a thin additional layer can make you feel much warmer.
The diagram below shows that CO2 has one of its absorption peaks right in the frequency range* of Earth's outgoing radiation:
Those of use who work on volcanic rocks already know this of course, since the absorption of infrared is one way measure the amount of CO2 dissolved in volcanic glasses. Some people (including, but not limited to cranks) embarrass themselves by not understanding this. BTW, a similar diagram was used in nice rebuttal of just such an attempt to refute the importance of CO2.
Then there are more ridiculous denials of the importance of atmospheric CO2.
"CO2 is plant food". Plants use carbon dioxide, so what? That's like saying plants need water, so water cannot cause floods.
"The lethal concentration of CO2 is 5,000 ppm and there's only 390 ppm in the air." That's like saying dew can't promote rust because there's not enough water to drown you. So many more, all logical fallacies
Alas, such nonsense appeal to those in Western civilazation who are scientifically ignorant and trapped in the selfish spiral and think any discussion of global warming and needed mitigation are part of some totalitarian plot hatched by far-away elites targeted at them. You know, the folks who think any penny of tax or regulation that provides the slightest hinderance to their ability to buy any luxury is the equivalent to slavery or being sent to the death camps.Its like an autoimmune overreaction in these people's psyche, and of course those comparisons belittle the experiences and defames the memories of slaves and concentration camp inmates.
I don't waste my energy arguing with such people (and won't here). There's a reckoning ahead for them entirely of their own making.
*I know its lazy to use a wiki image, but unfortunately I'm too busy to make my own from primary sources right now.