Climate change has been described as one of the biggest problems faced by humankind. Carbon dioxide is is the primary driver of global warming. Prof Joanna Haigh from Imperial College London explains why this gas has played a crucial role in shaping the Earth’s climate.

The planet is becoming increasingly hot. Whether the cause is human activity or natural variability—and the overwhelming evidence points to humans—thermometer readings have climbed gradually all around the world since the Industrial Revolution began.

Our lives are intertwined with the natural world. The environment encompasses everything we see, do, and breathe. If our environment contains dangerous contaminants, we will not be able to live a healthy life. Fresh air and a clean environment are...