It took 200,000 years for human numbers to reach one billion, in about 1800.The last billion took twelve years. The current rate of increase of about a billion every twelve years is the highest it has ever been.

Humans and their animals now account for about 97% by mass of land vertebrates: only about 3% by mass are wild. The number of wild animals has halved since 1970: in the same period, human numbers have doubled. Current species extinction rates are between 1000 and 10,000 times the natural background rate.

About 40% of land surface is already modified to meet human need. Most of the remainder is icecap, taiga, desert, mountain or rainforest.

Population pressure can lead to civil unrest, wars over resources, migration on a large scale and famine. Conflict over land and water is already occurring. We need to increase food production by at least 70% by 2050. This, however, will be in the face of desertification and degradation of agricultural land, rising sea levels, over-fished oceans, acidification of seawater and unpredictable weather as the result of climate change. Agriculture is heavily dependent on oil, a fossil fuel, the use of which must be restrained if we are to have a chance. Suggested solutions to the food problem include eating insects and protein extracted from sewage.

On the other hand, reduction of fertility rates is achievable, given political will. Several countries have achieved dramatic falls of fertility entirely without coercion.

There is absolutely no reason why the problem should not be confronted, and every reason why it should.

For more detailed substantiation of this case, see here

Roger Plenty, Nailsworth