Human population will not grow forever. In fact, it is forecast that human population may very well level off in the 21st Century around 9.5 billion people, which is about 2.5 billion more people than are living today. The prediction of population leveling off at 9.5 billion is predicated on the assumption that there will not be an ecological collapse prior to the time the 9.5 billion level is reached.

Given that we are already living beyond the carrying capacity of the planet with 7 billion people, the only way for the earth to be able to sustain anywhere near 9.5 billion people is for us to dramatically lessen humanity’s overall ecological footprint, our overall impact on the biosphere. Current trends in human consumption do not bode well for us being able to reduce our ecological footprint and live within the carrying capacity of the planet with our current 7 billion people, much less the projected 9.5 billion.

The stark reality we face is this: given current human consumptive activity, we are on a course for ecological collapse at some point probably before the middle of the 21st Century. This collapse will be exacerbated by climate change, especially if we do not make a radical reduction in our greenhouse gas emissions. Such a collapse will most definitely lead to a sharp human population decline, marked by great suffering, conflict, and death on a scale none of us has experienced before. This is not alarmism. This is simply the reality of too many people consuming too much, and the carrying capacity of the planet is being overwhelmed. All of the major ecological indicators are pointing in this direction.

There is only one way to avoid the ecological collapse that we are facing in the not too distant future, and that it is to reduce humanity’s overall impact on the planet so that we are not consuming more each year than the planet is able to produce in a sustainable way. This will require a significant reduction in how much of the planet’s resources we consume, and it will take a radical shift in how we produce and consume energy. If we cannot find ways to live within the carrying capacity of the planet with 9.5 billion people, we will need to find ways for there to be fewer people living on earth. We can either do this in humane ways by our choice (educational and economic opportunities for girls and women have proven to be the most effective) while simultaneously changing our consumption habits, or we can choose to continue to live beyond the carrying capacity of the planet and allow an ecological collapse to decrease our numbers. Some argue that making a case for there needing to be fewer humans on this planet is misanthropic (anti-human), but I think it is much more misanthropic to continue down a path that will inevitably contribute to human suffering and death on scale never known before. Finding systemic ways to reduce human consumption and having fewer children are two simultaneous approaches to take for a future with less rather than more suffering.