It is maddening, we seem to be stuck watching this happen in slow (well faster now) motion. I think a lot of people don't know exactly what to do, and while we try and make personal changes really we need government to regulate, cut subsidises etc.
It's frowned upon because the "solutions" to overpopulation are immoral. Over population causing climate change is an idea funded and perpetuated by large companies who do not want to take blame.
If the UK stopped producing carbon emissions tomorrow, I promise it would make an enormous difference: we're the 17th largest CO2 emitter despite having a relatively small population.
This is because: 1) average CO2 consumption of a person varies a lot by lifestyle: living more sustainably does matter, and,
2) the largest contributors to climate change are fuel companies, not individual people: many countries have much smaller carbon footprints (both total and per capita) because of their political choices. The best solution to climate change is political change and climate accountability, especially on the global scale.