Ch 17- The Human Disconnection Flashcards
Temporal Depth and Biocultural Evolution
- 225 million years of mammalian evolution
- 65 million years of primate evolution
- 6 million years of hominin evolution
- 2 million years of genus Homo evolution
Humans Impact on Climate Change
There have always been dramatic climatic fluctuations throughout Earth’s existence that had nothing to do with humans
- But greenhouse gases are raising earth’s temperature at a faster rate than has ever been seen
- Outside the range of normal – never this fast in the past
- Much of it comes from burning of fossil fuels – is due to human activity
Polar Ice
- Reflection %s
- Why are scientists worried about this?
Most sensitive areas on Earth to warming
- Sea ice reflects back into space 80% of sunlight that hits it
- Seawater absorbs 90% of sunlight that hits it
• As more ice melts less sunlight is reflected and more heat is retained resulting in more warming and melting
- Worried the polar regions may have reached a point where warming process cannot be reversed
Mass Extinction Events
How many?
What are they caused by?
In last 570 million years 15 mass extinction events
Two of them altered global ecosystems
- Caused by continental drift, massive volcanoes, asteroids
- A third is occurring now- caused by Homo sapiens
• Species disappearing at an unprecedented rate
New Geological Era??
Whats it called?
From when to when?
The Anthropocene
- “The age of humans”
- 250 years ago to today
Acceleration of Evolutionary Processes
- Antibiotic resistant bacteria
- Overuse and misuse of insecticides and pesticides on crops
Why is Global population Growth Slowing?
Rate of global population growth is slowing
- Tied to improved education of women and girls; decreased infant mortality; rising household income
- Hope this will led to less habitat destruction and jobs in environmental conservation
