As discussed in our last unit of freshman biology (can’t believe its almost over!), there are ways that ecologists and other scientists can predict global warming based on historical trends. In the textbook, the warming preceding the last ice age was characterized by glaciers and trees retreating to the north and south poles. It further states that based on the rate at which the biosphere is warming now, trees would need to retreat at about a 7-9 km rate whereas they are only moving at about a .2 km rate currently. The latest National Climate Assessment, released May 6, outlines the climate changes in the US; I have skimmed through the introduction (the whole document is 840 pages!) and have found a section on melting ice and glacier migration – here is a paragraph I found both relevant to our current unit (tundra biome, chemical cycles, and global warming) and interesting: “Glaciers are retreating and/or thinning in Alaska and in the lower 48 states. In addition, permafrost temperatures are increasing over Alaska and much of the Arctic. Regions of discontinuous permafrost in interior Alaska (where annual average soil temperatures are already close to 32°F) are highly vulnerable to thaw. Thawing permafrost releases carbon dioxide and methane – heat-trapping gases that contribute to even more warming. Recent estimates suggest that the potential release of carbon from permafrost soils could add as much as 0.4ºF to 0.6ºF of warming by 2100.” There are many implications associated with the many areas affected by dramatic climate change, and we must bring them to our attention. Good luck all on your finals! It’s been a great semester.