Given how little governments are doing to combat climate change, it may take more participation from individuals to prevent its worst impacts. Driving, flying, and eating animals cause significant harm, but not having children may be the best decision we can make to save the planet.

Children significantly contribute to environmental degradation. According to research, the most effective way to reduce climate impact is to not have children–an even more significant impact than being vegetarian. In a baby’s first two years, they consume about 5,000 diapers. Diapers contribute to ozone depletion and toxic waste. According to the EPA, babies generate about 4.4 pounds of waste per day and about 80,000 pounds in their first 50 years. That’s packaging, bottles, newspapers, paint, batteries, clothing, appliances, school supplies, bicycles, and glass jars. The child’s impact from the consumption of these items contributes to consumerism, deforestation, land and water degradation, and greenhouse gas emissions, and it continues for decades as an adult leading to an average additional 82-year carbon footprint.

According to the Department of Agriculture, the average cost of raising a child in the U.S. from birth through age 17 is $247,910. That’s before college. According to the College Board, the average cost of college today is $140,000. Thus, a child costs about $400,000. With $400,000, you can protect 400,000 people, plant 400,000 trees, or save thousands of animals through top-rated charities.

There are about 153 million orphans in need of a safe and loving home. Although this is a personal choice for every family, providing a home to a child who already lives, suffers, and longs for love is humane and kinder to the planet. Children never born don’t miss anything because they never exist. People don’t need to create new children for entertainment or love. And as Ricky Gervais jokes, there is not a line of ghost fetuses begging to be born.

The world is struggling to handle more children. At a current estimate of 7.5 billion people, scientists predict we’re on an unsustainable path. Overpopulation devours finite natural resources, or uses them in a way–fossil fuels, for example–that degrades the planet. Fewer babies will help solve issues that cause so many animals and people to suffer.

It could be cruel to bring a child into the world given the threats the planet faces such as unprecedented storms and flooding unless the current greenhouse gas emissions patten is significantly reversed. Billions of people also live unhappy lives–victims of rape, domestic violence, terrorism, disease, poverty, natural disasters, and mental illness. Having a child comes with significant risks to the child’s well-being.

Parents, especially vegan parents, argue that it’s important for compassionate people to have children. But people don’t need to have children to raise kind children. They can teach or volunteer and impact many more children, or adopt. The science is clear–empathy can be taught. There’s also no guarantee that people’s children will grow up to do good simply because they instill their values. Many children choose different paths despite their parents’ best efforts. Children often don’t resemble the etiquette, interests, or performance of their parents.

Given the impact of children on the planet, you may wish to reconsider bringing more children into an overpopulated world. Having children no longer makes sense. We’re facing an unprecedented climate crisis and threats to finite resources. Meeting the challenge requires everyone to think critically about long-held cultural norms. We must change the way we eat, consume, travel, and populate the earth if we’re going to save it.