pretty clear that the implication is right to life of a human being > right to privacy of mother

edit: fetus -> being

The thing with climate change, as it is postulated, is that there might be no next generations, or that they will be severely limited in their moral choices by civilization collapse.

So putting both on the same desk is really misleading.

Global warming doesn't pose a human extinction or civilizational collapse level threat in the next century. Tens or hundreds of millions of deaths, untold quantities of suffering, habitat destruction, and huge economic losses are within reason, but humanity would take that on the chin and carry on. 80 million young men, many from wealthy countries, died fighting in WW2, and European infrastructure took a huge hit. You can barely notice the impact on a global gdp chart, and it's invisible on population.

Abortion may also have long term consequences, though they would almost certainly be less severe. Genetics that are beneficial to humanity may also increase abortion likelihood- eg. educated women are more likely to be intelligent and to abort compared to the general population. Or the inverse, genes that act against abortion may be bad for humans at large- eg. whatever makes people fundamentalist. But these are just speculations, and it may even wind up being beneficial.

I agree that the two are not on the same order of magnitude, but it's less cut and dry than comparing zero and infinity.