Malthus was refuted by the early 19th century on economic grounds - namely that the pricing system prevents people from over-exploiting scarce resources.

While there has certainly been some poor husbandry of the earth's resources, there have been and continue to be significant efforts to improve resource utilization in environmentally friendly ways - not the least of which is increased costs of basic resources leading to self-imposed limitations by consumers.

Basically, on net, people choose more luxury over more children. They economize when presented with prices that reflect the reality of underlying scarcity. They make choices that often result in improved environmental stewardship, either implicitly or explicitly.