Platform: The population explosion is a danger to all of mankind

OPT members in Scotland think population growth is a danger to mankind's future, and why entirely voluntary family planning is an appropriate response.

Earth's environment is severely stretched, from biodiversity loss and climate change to energy concerns and the increasing numbers lacking food and water. This is partly due to industrialisation and rising consumption, but also population growth. World population, three billion just 50 years ago, is approaching seven billion, and is predicted to reach nine billion by 2050.

The Scottish population has doubled since 1870. Numbers increased by 25,500 during 2008-9 and growth is predicted to continue.

While Scotland remains greener and less crowded than England and has been fortunate in its energy supplies, we feel amenities and resources should be conserved. Also, Scotland depends on imports for much of its food, an uncomfortable position as population and per capita consumption soar worldwide.

The most eco-friendly thing we can do is think about the number of children we have. Of course, not every child is planned – the Family Planning Association reckons 40 per cent of conceptions are unplanned and 30 per cent unwanted. Surely we can do better than that? Most women prefer smaller families given the choice. Yet 200 million women in developing countries lack family planning services. This needs to be a priority for international aid, for health and environmental reasons.

The dire environmental consequences of our unprecedented numbers are increasingly clear. And, given people do limit their children given the motivation and means, it's in everyone's interests that these are provided.

• Penny McKee is a member of the management committee of OPT Scotland