Visualizing climate change

Humans are profoundly affecting the planet, and human-caused, or anthropogenic, climate change is the most visible manifestation of this today. In the graph above, from the National Oceanic and Atmospheric Administration, trends in atmospheric carbon dioxide (CO2) are shown from the present (at far right) back through several ice age cycles, to eight hundred thousand years ago (800 kyBCE, or thousands of years before the Common Era). On this longer timescale, the carbon that humans have added to the atmosphere from burning fossil fuels is seen to be more akin to an instantaneous shock rather than a gradual, inexorable increase that is observed over a person’s lifetime.