3.75ppm, but yes - to be clear, worldwide emissions are continuing to increase, so the CO2 level should be rising by more and more every year.
If we can level off our greenhouse emissions (and we're very close), the CO2 level should continue to rise each year, but at a roughly-constant rate.
And if the world can get approach net-zero greenhouse emissions (a reasonable goal for 2050), the CO2 level should stop growing.
And then, we would need a few centuries of negative greenhouse emissions to get back to pre-industrial temperatures.
I suspect we'll never bother to do this.
