How much carbon dioxide (and other kinds of greenhouse gas) is already in the atmosphere?
One of the strongest pieces of evidence for human-induced climate change is the consistent rise in carbon dioxide (CO2) in modern times, as measured at the Mauna Loa Observatory in Hawaii, where CO2 has been observed since 1958. As of December 2008, the concentration of CO2 in Earth’s atmosphere was about 386 parts per million (ppm), with a steady recent growth rate of about 2 ppm per year. Because CO2 stays in the air so long, it becomes very well mixed throughout the global atmosphere. This makes the Mauna Loa record an excellent indication of long-term trends.
One of the strongest pieces of evidence for human-induced climate change is the consistent rise in carbon dioxide (CO2) in modern times, as measured at the Mauna Loa Observatory in Hawaii, where CO2 has been observed since 1958. As of 2005, the concentration of CO2 in Earth’s atmosphere was about 378 parts per million (ppm). • What does the ozone hole have to do with climate change? There are a few connections between the two, but they are largely separate issues. First, it’s important to know that ozone plays two different roles in the atmosphere. At ground level, “bad ozone” is a pollutant caused by human activities; it’s a major component of health-damaging smog. The same chemical occurs naturally in the stratosphere, and this “good ozone” acts as a shield, filtering out most of the ultraviolet light from the Sun that could otherwise prove deadly to people, animals, and plants. • Aren’t the computer models used to study climate really simplistic?Global climate models—the software pa
