I've only just remembered writing a similar post back in 2006 about the Episcopalian Church in the US (the American equivalent to the Anglicans). The Episcopalians commissioned a report to find out why they had lost 829,000 members between 1967 and 2002. The main finding was that the educated whites who made up the core of the Episcopalian Church had a low fertility rate of only 1.5.
So did the Episcopalians conclude that they should encourage family formation amongst their congregation? No, not at all:
Q. How many members of the Episcopal Church are there in this country?
About 2.2 million. It used to be larger percentagewise, but Episcopalians tend to be better educated and tend to reproduce at lower rates than some other denominations. Roman Catholics and Mormons both have theological reasons for producing lots of children.
Q. Episcopalians aren't interested in replenishing their ranks by having children?
No. It's probably the opposite. We encourage people to pay attention to the stewardship of the earth and not use more than their portion.
So environmentalism is being used here too to justify declining numbers and significance. It's as if the church leaders are saying, well we're not going to be a very significant church in the future, but that just shows how superior we are in our morals since we're demonstrating green credentials.
That seems hopeless to me. There are literally millions of illegal immigrants arriving in the US, fueling massive population growth. The environment is not being protected. So Episcopalians not having children is not serving any purpose at all. It's just hastening the process by which one population (of educated whites) is being replaced by other populations.