In 1987 the UN designated July 11th World Population Day to build awareness of the impact population has on development and the environment. As of this writing, the world population is estimated to be 7.239 billion. Roughly 40% is under the age of 25. The UN estimates we will grow to 9.5 billion by 2050. We are at a critical moment in history. If population growth continues as projected, living conditions will become bleaker; and water, food and land will become scarcer.

My interest and involvement in population were fueled by a flight over the island of Hispaniola, an island shared by two nations – Haiti and the Dominican Republic. Only 2% of Haiti remains forested because of the population’s high demand for wood and charcoal for fuel as well as a history of monoculture which has exhausted the soil.

The Dominican Republic, on the other hand, enacted a strict forestry law which helped them regrow their forests on over 40% of their land. Both countries had fertility rates between six and seven children in the 1960s, but they began to come down in recent decades, until Haiti’s earthquake in 2010. Haiti’s fertility rate tripled after the earthquake because of lack of access to contraception, education and unsafe living conditions for women.

While population growth has slowed globally, the absolute number of people continues to increase – by about 1 billion every 13 years. Slowing population growth would help improve living standards and would help to protect natural resources in developing countries. Unfortunately there are still 44 countries where the average woman has five or more children. Niger, Mali, Somalia, Uganda, and Burkina Faso all have a fertility rate of six or more. In these countries, women have few choices of their own.

As the world’s population grows, improving living standards without destroying the environment is a global challenge. Natural resources are under increasing pressure: water shortages, soil exhaustion, loss of forests, air and water pollution, and degradation of coastlines affect many areas.

Polluted water and poor sanitation kills over 12 million people each year, mainly in developing countries. Air pollution kills nearly 3 million more. In 64 of 105 developing countries studied by the UN Food and Agriculture Organization, the population has been growing faster than food supplies. The supply of freshwater is finite, but demand is soaring as population grows and use rises.

The earth’s biological diversity is crucial to the continued vitality of agriculture and medicine – and perhaps even to life on earth itself. Yet human activities are pushing many thousands of plant and animal species into extinction. Ocean fisheries are being exploited, and fish catches are down. Nearly half of the world’s original forest cover has been lost.

These growth patterns closely track how women and girls are treated.

Women have a basic human right to determine freely and responsibly the number and timing of their children. Estimates suggest that more than 220 million married women – virtually all of them in developing countries – want access to birth control but cannot get it. With greater access to birth control women would have greater employment opportunities and be able to improve the economic condition of their families.

If population growth slows, countries can invest more in education, healthcare, job creation, and other improvements that boost living standards. As individual income, savings, and investment rise, more resources become available that can boost productivity.

When family planning information and services are widely available and accessible, couples are better able to manage the size of their family. If every country made a commitment to population stabilization and resource conservation, the world would be better able to fulfill sustainable development. Until then, the environment hangs in the balance.

Rachel’s Network Member Janet Miller is a trustee of the WestWind Foundation, which focuses on environmental programs and reproductive health and rights, primarily in the Latin American and Caribbean regions. These grants have supported NGOs that protect forested ecosystems, especially through habitat and watershed conservation.