Consequences are rife Arguably the most dire: EXTINCTIONS One recent study (Burkhead M, 2012, Extinction rates in North American freshwater fishes, 1900–2010. Bioscience) USGS researchers examined contemporary (1900-2010) extinction rate for freshwater fish in North America They compared contemporary extinction with rates derived from examination of freshwater fish in the fossil record Fossil record showed approximately 1 extinction/3 million years The contemporary rate was 877 times higher Not surprising since NA wetlands are literally under human assault. In the US for example 50% of our historic wetlands have been destroyed. Humans are impacting the globe so drastically there is a massive campaign in effect to name a Anthropocene new geological era, the Why so much green in Siberia and the arctic and N. Africa? So this says it all. The other instructors have a slide: Reasons for optimism 1. World population growth has slowed substantially Brazil in 1960 – birth rate of 6.4 In 2010 – 1.9 (compare to US at 2.0)
Consequences are rife Arguably the most dire: EXTINCTIONS One recent study (Burkhead M, 2012, Extinction rates in North American freshwater fishes, 1900–2010. Bioscience) USGS researchers examined contemporary (1900-2010) extinction rate for freshwater fish in North America They compared contemporary extinction with rates derived from examination of freshwater fish in the fossil record Fossil record showed approximately 1 extinction/3 million years The contemporary rate was 877 times higher Not surprising since NA wetlands are literally under human assault. In the US for example 50% of our historic wetlands have been destroyed. Humans are impacting the globe so drastically there is a massive campaign in effect to name a new geological era, the Anthropocene Why so much green in Siberia and the arctic and N. Africa? So this says it all. The other instructors have a slide: Reasons for optimism 1. World population growth has slowed substantially Brazil in 1960 – birth rate of 6.4 In 2010 – 1.9 (compare to US at 2.0)
2016%20Lecture%2001%20-%20Introduction.docx