Global warming is a hot-button topic in today's news, but perhaps if the world had acted on it when it was first feared, we wouldn't be dealing with it now. In 1896, a Swedish scientist named Svante Arrhenius became the first person to link the Earth's temperature with carbon dioxide concentrations in the atmosphere, and he warned that the burning of fossil fuels could lead to more carbon dioxide and therefore warmer temperatures. No one paid much attention, even as Arrhenius and colleague Thomas Chamberlin worked out calculations to show how human activity would lead to climate change. They figured out that the natural greenhouse effect on Earth keeps the planet at approximately 59 degrees F (15 degrees C), but that doubling the carbon dioxide concentration would raise it to 68 degrees F (20 degrees C). Despite the work, people generally maintained that human activity did very little to affect the Earth, and that things like solar activity and ocean circulation had much more to do with how cold or hot the planet would get. Today, of course, approximately 97 percent of all climate scientists agree that people are causing climate change.
A hot topic:
- The five warmest years on record have occurred since 2010.
- On average, Greenland has lost 286 billion tons of ice a year since 1993, while Antarctica has lost 127 billion tons per year.
- During the 20th century, global sea levels rose about 8 inches (20.3 cm); the rate in the last two decades is almost twice as much.