Men don't have a biological clock

In reality, men face a decline in sperm count and quality as they age. Older men are also more likely to have children with disorders. The research is mixed on how soon this becomes a noticeable problem, but one thing is clear: male biological fertility declines markedly over time too.

Men can just delay parenthood and marry a younger woman

The average age gap in heterosexual married couples is 2–3 years in the UK, with gaps of over 10 years being very uncommon. Guys can’t just rely on marrying a younger woman to have kids.

Women can wait risk-free to 30+ to have family

To have a 90% chance of having 3 children without IVF, a woman needs to start trying for children at 23 years old. With IVF, the age raises to 27.

During the 30s, it continues to get more difficult for women—the risk of being in an infertile couples rises by 36% for women between the age of 30 and 35. Most 40 year old women trying for children are in infertile couples.

You can just use IVF in your late 30s/early 40s

IVF success rates are around 1 in 6 for women aged 40–42. It’s still less than 1 in 10 for women aged 43–44.

Children are terrible for carbon emissions

The study that found this used outdated emissions data from when Western world emissions were at their highest. Once the downward trend in emissions is taken into account, even if Western fertility was restored to replacement level, it would only add 0.05 degrees celsius in warming by 2200.

We can't feed more people

Various models and papers have found that we can sustainably feed more than 10 billion people and global population is not currently forecast to exceed that level.