The COP25 climate change summit that just wrapped up in Madrid, Spain, was not the decisive plunge into climate action the world needed. In the lead up to the conference, 11,000 scientists declared “clearly and unequivocally that planet Earth is facing a climate emergency,” and half a million protesters in Madrid demanded we act accordingly. In the end, however, UN Secretary-General António Guterres tweeted the world “lost an important opportunity.”

Unable to reach agreement on new rules for carbon trading or funding for climate change adaptation, the proverbial can was kicked down the road. Again.

We urgently need action on climate change, but even if we get it, there are larger issues. It’s not just climate. Humanity is overwhelming the planet, its resources and its life-supporting capacity. We are not in any danger of extinction, not yet anyway. But the human juggernaut — and the needs and aspirations that propel it — is headed for a day of reckoning.

Economists like to say that inflation is what happens when there is “too much money chasing too few goods.” If a government keeps printing too much money, runaway inflation and economic collapse ensue. Something analogous is happening today in the natural world, where too many demands are chasing too few resources. If we keep piling more and more demands on our limited supply of land, water and other resources, nature will inevitably collapse.

Beyond the environmental toll, there’s an escalating human cost: homes destroyed by wildfires and catastrophic storms and farms decimated by severe drought, rising temperatures or falling water tables. Young men in many parts of Asia and Africa are abandoning their rural communities in search of jobs in cities, and desperate mothers in the highlands of Guatemala and other drought-stricken areas are forced to migrate to feed their children.

When there are too many demands chasing too few resources, conflict can arise. Like in Sudan, where water scarcity fueled ethnic tensions. Or places like Mali and Niger, where fights break out between herders and farmers during drought. In the future, a rising tide of climate refugees could destabilize entire regions and contribute to global political dysfunction.

We are experiencing a planetary emergency. Climate action is the first priority, as time is quickly running out. But we must also come to grips with the other challenges created by an expanding human footprint, including water scarcity, food insecurity and the extinction of plant and animal species.

We need to downsize the human enterprise. We must address world population, which the UN now projects will rise from 7.7 billion today to nearly 10 billion by mid-century and nearly 11 billion by the end of the century. We also must deal with the sheer size of the global economy, which by some estimates could double by mid-century or earlier.

Advancing reproductive freedom could dramatically lower the world’s projected population growth. All women need access to contraception; that’s fundamental. But beyond that, in the developing world, where the vast majority of the world’s population growth is occurring, we should invest in the education of girls, eliminate child marriage and empower women. Smaller, healthier families are better equipped to deal with climate change.

Reining in resource depletion and environmental degradation is a harder task, but not impossible. It will require a fundamental reworking of capitalism, starting with carbon taxes, and a much larger tax overhaul that stiffly penalizes pollution and resource consumption. We must also ensure that technology, which now accelerates resource depletion, becomes our ally in the fight for global sustainability. Artificial intelligence could help us chart a sustainable course, but only if we act on the insights it provides.

The human enterprise is not without hope, but if future generations are to prosper, not merely survive, we must curb our overconsumption of resources and become better stewards of the planet.

This op-ed by Population Institute President Robert Walker originally ran on December 17, 2019 in The Baltimore Sun