AFAIK the only environmental goal that we met was the Montreal protocol and the elimination of chemicals harming the ozone layer.

As a result of the international agreement, the ozone hole in Antarctica is slowly recovering. Climate projections indicate that the ozone layer will return to 1980 levels between 2040 (across much of the world) and 2066 (over Antarctica). Due to its widespread adoption and implementation, it has been hailed as an example of successful international co-operation. Former UN Secretary-General Kofi Annan stated that "perhaps the single most successful international agreement to date has been the Montreal Protocol".

I think we also did something about acid rain for a few decades now but I can't find any specific agreement. All I know is that I'm in my 40ies and thus old enough to remember it was an issue when I was a kid, and that the US and Canada agreed to do something about it.

Some governments, including those in Europe and North America, have made efforts since the 1970s to reduce the release of sulfur dioxide and nitrogen oxide into the atmosphere through air pollution regulations. These efforts have had positive results due to the widespread research on acid rain starting in the 1960s and the publicized information on its harmful effects.

I don't know what changed but apparently, we don't really care about the rest now.