Earth Day

Happy Earth Day. The annual observance has survived primarily as a time to reflect on the environment. Of special importance is that we now find ourselves in the Sixth Great Extinction of the planet's known paleologic history. In this current Holocene Extinction we are losing species at an estimated rate of about 70 a day, or some 25,000 a year. That is many times the "normal" rate over geologic time, which is about five taxonomic families per each million years.

The low estimate for extinctions in the Twentieth Century is 140,000 species. The upper is about a million. Most noteworthy since 1950 is the accelerated number of plant extinctions. It is estimated there are 10-11 million species on Earth, most of them microscopic. Twelve of the thirteen major fisheries on the planet are evidencing severe depletion. There are only 148 large mammal species (average mature individual weighing over 100 pounds) left in the wild.

Here are some of the greatest threats. Either we will deal with them in the next decades or the inexorable laws of chemistry and biology will deal with them--and us--in their own immutable fashion.

1. Greenhouse gas buildup in the atmosphere. Causes global warming, changes precipitation patterns, spreads diseases into new biomes, raises sea levels, intensifies cyclonic storms, renders current growing areas unsuitable.
2. Habitat destruction.
3. Spread of invasive species.
4. Over exploitation of biological resources.
5. Release of heavy metals into biomes and water table.
6. Evolution of resistant pathogens.
7. Soil depletion and erosion.
8. Desertification of savanna regions.
9. Environmental release of pharmaceutical compounds.
10. Poverty. Dire third-world poverty in particular results in the stripping of any and all consumables from a landscape, leaving it barren.