Roughly 10% of the land area on Earth is covered by glaciers– most of this number comes from the Antarctic and Greenland ice sheets. Other areas of permanent ice are scattered around in places like the Rockies, Alps, Andes, Himalayas, etc. Ice also covers roughly 7% of the oceans in the annual mean, though both hemispheres experience sea ice loss in their respective summers, and regrowth in their winters. Around 75% of the freshwater on Earth is stored in glaciers, and they provide water for millions of people worldwide. Glaciers form when more snow falls each year than can melt or evaporate. The snow piles up, is squeezed into ice under the weight of more snow (with an intermediate form called ‘firn’), and begins to flow under gravity. Such conditions are generally a function of both temperature and precipitation and are dominant at low latitudes and high altitudes, or high latitudes.
Archive for February, 2008
just a few more molecules…
Greenhouse gases make up about a percent of all of the molecules in the atmosphere, and CO2 makes up about .038% by volume. That is an increase from .028% from pre-industrial time (fixed– comments). That means that today, if you went through the atmosphere sifting through molecules and collected one million of them, you should only find 380 that were CO2. There are often remarks which read like “how can such a small amount make such a large difference?”
Global Warming maps/graphs
How much warmer is the Arctic becoming compared to the globe?? What exactly is the story in Antarctica?? Why does the Northern Hemisphere warm faster than the Southern Hemisphere?? Does global warming imply warming at all sites?? What happens when you add, or remove CO2??
