So my country's subreddit (/r/NewZealand) has a popular post up at the moment regarding how the best way to limit climate change is to have fewer kids. I responded by saying that it was relatively easy to have a net-negative climate impact, and that if you teach your children well, you can multiply your impact across generations. I've been saying the same thing for years, and generally its well received by Millennials as a response to Boomer rhetoric (in effect, I characterise the fewer kids idea as "we've had our fun but caused this problem. You need to change and fix it."). On this occasion, it received 50/50 up/downvotes but no direct responses. It's an interesting data point to me, and perhaps indicates a change in mentality on this issue. I'm not sure.
I find some modern environmentalist movements baffling and thinking about it as a religion is probably the best way to go about it. I also noticed that there is certain kind of environmental activists that value personal sacrifice over actual efficacy of action. This really seems almost a religious act - like fasting or even flagellation - where it is the pain and discomfort that is the good on its own and religion just provides the necessary impetus for this psychological need.
Now for me the environmental question is purely technical one. I will use two examples. For instance on individual level the average total CO2 emissions are ranging from 5 to 20 tons a year depending on lifestyle. The market price of carbon permits now is around $30 per ton. There already are initiatives that enable private persons to purchase these permits and organizations facilitating this trade promise not to actually emit anything. Using this method you can offset your emissions for around $150 - $600 a year. If you have a child you can setup a carbon offset trust fund that will offset the carbon in perpetuity. If one expects let's say 4% return you can achieve perpetual carbon offset by this method investing $4,000 - $ 15,000. The advantage of this method of offset is that the carbon permit revenue is in most countries heavily earmarked for implementation of green technologies. So what this means is that in the end the offset is real if one believes that the revenue from carbon permits is invested in CO2 srubbers or for subsidies of renewables or even basic research and other initiatives.
If one does not believe in efficacy of carbon permits then there is still possibility to select and support your own methods. Probably the cheapest is just plant trees. I googled around and this guy says that to offset around five tons of CO2 you need to plant around 200 trees. According to this site you can have one tree planted for cost of $0.1 to around $2 per tree. So to offset your carbon footprint of 5-20 tons you may need as little as $20 to maybe around $2,000 a year. Let's go with higher number. So again if you want to plant trees in perpetuity you need to create a trust fund of $500 - $50,000.
Now there are also machines that can absorb and store CO2 directly from air. The cost is now quite high - according to this article it is around $600 per ton. So your yearly offset price tag can range from $3,000 to $12,000. The perpetual trust fund to finance CO2 capture on this level is then ranging from $75,000 to $300,000. One advantage of this method is that you actually invest into a technology that promises to bring costs down by order of magnitude in near future. So in fact I believe that by the end of your life the trust fund necessary will be much lower. You can even use a mix of different carbon offset method to diversify your bets.
You can have similar discussion about other hyped aspects of environmentalism. For instance I googled that the full cost of disposing garbage in modern landfill in Australia is around $100 per ton. The average american produces less than a ton of garbage, but let's round it up. So garbage can be safely stored for $100 a year and wait buried in the ground even for centuries until there are cheap way to dig it up and even make profit. The modern landfills are marvels of engineering and work very well.
Again what I wanted to demonstrate s that environmental problems are first and foremost science/engineering problems. You can literally put a price tag on their solutions - and the price is actually within means of your average middle-class citizen in modern western country. Now this is anathema to certain kind of activist. These people made tough decisions or great compromises and completely turned around their lifestyles. They may have decided not to have children or go to great lengths to obsess about their daily decisions - from zero waste activists to people who travel to USA on sailboats or similar. To tell to these people that all their effort is worth couple hundred bucks a year does not go over well to put it mildy. These activists view their lifestyle as moral impetus. Putting a price tag on morality is unthinkable.