By far the most important thing you can do to fight climate change

You've probably seen several similar articles and studies: what's the best and most effective thing you can do to reduce your carbon footprint. You know: switch to an electric car, turn vegetarian, change your light-bulbs, that kind of thing.
Here, though, is a similar study that includes an option not usually considered. A joint study by researchers at Lund University in Sweden and University of British Columbia in Canada looks at lifestyle choices with the greatest potential to reduce personal greenhouse gas emissions. Here you will find the usual solutions live car-free (an annual saving of 2.4 tons of CO2 equivalent), avoid one transatlantic air flight a year (1.6 tCO2e), but green energy (1.5 tCO2e), switch to a more efficient car (1.2 tCO2e), adopt a vegetarian diet (0.8 tCO2e).
But the elephant in the room is right at the top of the chart: have fewer children (58.6 tCO2e). So, bringing one less kid into the world is nearly 25 times more effective at reducing greenhouse gas emissions than the next best choice, and significantly more effective than all the other choice combined (I assume it is based on a standard developed "Western" lifestyle - one fewer child in Africa or Asia, while perhaps desirable for other reasons, would not have anything like as much effect on our carbon footprint).
It's interesting that this is the first study I have seen to account for this most basic of decisions. And it is a decision over which we have direct control, generally speaking. It's not an option for me personally at this point in my life, although I am responsible for just a modest single child (and an environmentally responsible one at that). But it is good to finally bring such facts out into the open.