Connecting Population Growth and Climate Change

Will Humans Save the Planet?

Evolutionary biologist and historian of science, Manfred Laubichler, recently wrote about the connection between human population growth and climate change. In his article, published by The Conversation, Laubichler shares: “The more people we have on this planet, the larger their collective impact on the climate. A closer look with a longer time horizon reveals relationships between population size and climate change that can help us better understand humanity’s predicament as the global population nears 8 billion people.”

Laubichler believes that “as humans evolved, the demands of the growing population, associated knowledge creation, and energy use created a feedback cycle.” He calls this process the Anthropocene engine. He breaks down the evolution of this system, saying:

“First, populations had to reach a critical number of people to successfully create enough knowledge about their environments that they could begin to actively and purposefully transform the niches they lived in.

Successful agriculture was the product of such knowledge. In turn, agriculture increased the amount of energy available to these early societies.

More energy supports more people. More people led to early settlements and, later, to cities. This allowed for task specialization and division of labor, which, in turn, accelerated the creation of more knowledge, which increased available energy and allowed population size to grow as well. And so on, and so on.”

This evolution of progress has, over time, allowed human population to grow. Humans have avoided extinction by successfully implementing systems to produce and distribute food and significant medical advancements.

The problem with this, as Laubichler explains, is that exponential growth depletes resources at an unnaturally accelerated pace, creating a dangerous supply and demand imbalance between the earth and its inhabitants. “The disappearance of the Easter Island civilization and the collapse of the Mayan empire, for example, have been linked to the depletion of environmental resources as populations rose,” he notes.

Bringing readers to the present, Laubichler highlights the path humanity must take to survive, saying: “Every species, if left unchecked, would grow exponentially. But species are subject to constraints – or negative feedback mechanisms – such as predators and limited food supplies.” Connecting human action to today’s climate change concerns, he adds: “Introducing negative feedback into our socioeconomic-technical systems – not as radical population control or war, but in the form of norms, values, and regulations on excess greenhouse gas emissions – can help keep climate change in check.”

NPG agrees with Mr. Laubichler’s proposed approach of introducing negative feedback into society in the form of norms, values, and regulated greenhouse gas emissions. We must slow, halt, and eventually reverse population growth in the United States to preserve the earth for future generations. In response to the article, Edwin S. Rubenstein, Director of Research for NPG, shared: “It’s always good to step back and consider the totality of human existence – which Mr. Laubichler does brilliantly in his article. Unfortunately, our brains are programmed to focus on small steps immediately before us rather than the mega-trends highlighted by Laubichler.”