Blue question mark

What is the single most harmful thing humans are doing to Earth? How is it harming our Earth and what will happen if we don't fix the problem?
— Melissa J., Grade 7

Herpetologist Raoul Bain answers this question:

Dear Melissa,

There are many harmful things that humans are doing to Earth . So it's hard to pick just one that is the most damaging. Here are two examples of how humans are harming the environment.

First, we are rapidly changing large portions of the environment, such as when we cut down a forest to make way for a town. This is harmful because all forms of life live in the forests — from the tops of the trees to deep into the ground. So once the forests are gone, most of that life is gone with it. Forests also help to provide the oxygen that we breathe , as well as the clean water that we drink.

Arial view of a city with hightways

The building of new towns changes the landscape.

Secondly, we are also rapidly changing the environment by adding too much waste to it, such as when cars and generators release carbon dioxide (CO2) into the air. Releasing waste is natural and necessary. Plants need CO2 to live, and one of their waste products is oxygen, which we need to live. But we are releasing so much CO2 into the air that the plants cannot possibly use it all. And there are fewer and fewer plants to use it when we cut down forests. The extra CO2 that collects in our atmosphere is a major cause of global warming.

Cars and trucks on a traffic filled highway

Cars release CO2 into the air.

It would be easy to say "Stop cutting down forests!" and "Stop putting so much CO2 in the air!" But this would mean that we would have to find new ways to house ourselves and grow our crops, stop driving cars, and stop using electricity generated by fuel. This would be very difficult, maybe impossible, for us to do as a society.

wind turbines

Other forms of energy, like wind energy, can generate electricity without emitting CO2.

Instead, we should only cut forests in a sustainable way and think of ways to move cars or generate electricity so that they do not add CO2 to the air. This is why, for example, people are trying to build cars that run on hydrogen and release water instead of CO2. This is also why people are trying to generate electricity using the Sun , wind, or ocean tides so that there are no emissions at all.

We can each moderate our CO2 emissions by doing things like walking or riding bikes instead of driving. We can also turn off lights or machines when we aren't using them. But we have a long way to go.

Explore More:

Raoul Bain

Raoul Bain

Job Title:
Biodiversity Specialist, Center for Biodiversity & Conservation

Known For:
Raoul is a herpetologist — he studies amphibians and reptiles. Raoul goes on research expeditions to survey biodiversity  around the world, including Bolivia and Vietnam. He also trains international scientists in conservation techniques.

Cool Fact:
Raoul is an expert in the amphibians and reptiles of southeast Asia. His work has led to the discovery of many new amphibian species in Vietnam!

Image Credits:

urban sprawl, courtesy of USGS; traffic, courtesy of; wind turbines, courtesy of NREL; Raoul Bain, courtesy of Raoul Bain.