The biggest problem with the greenhouse effect is the large timescales at play - the CO2-emissions of today will cause problems for centuries, and even if we would stop using fossil fuels completely tomorrow, we will still get significant problems with greenhouse effect.
Luckily, the ozone layer replenishes itself pretty fast, and the ozone-depleting chemicals are pretty short-lived at those heights (50-100 years according to wikipedia). Those chemicals have been almost banned internationally, and as a result ozone levels are already on the way back to the old normal (and will probably be back at 1980-levels around 2050 according to wikipedia). It's almost a forgotten problem. It's one of the rare cases where international cooperation has been successful on tackling a global environmental problem.