THE LIFESAVER AND KILLER

By trapping heat from the sun, greenhouse gases have kept the earth’s climate habitable for humans and millions of other species, but these gases are now out of balance and threaten to change drastically which living things can survive on this planet and where they can live.

Atmospheric levels of carbon dioxide, CO2, the most dangerous and prevalent greenhouse gas, are at the highest levels ever recorded. Greenhouse gas levels are so high primarily because humans have released them into the air by burning fossil fuels. The gases absorb solar energy and keep heat close to the earth’s surface, rather than letting it escape into space. That trapping of heat is known as the greenhouse effect.

Today, climate change is the term scientists use to describe the complex shifts, driven by greenhouse gas concentrations, that are now affecting our planet’s weather and climate systems. Climate change encompasses not only the rising average temperatures we refer to as global warming but also extreme weather events, shifting wildlife populations and habitats, rising seas, and a range of other impacts.

Governments and organizations around the world, such as the Intergovernmental Panel on Climate Change (IPCC), the United Nations body that tracks the latest climate-change science, are measuring greenhouse gases, tracking their impacts, and implementing solutions.