Human Impacts on Earth

1
Human Impacts on Earth

• Biology 150-009
• Ms. Chappell
• September 7, 2006

2
Are We the Problem?

• Humans are not alone in creating changes to the
  biosphere
• Nature can make big changes too (large and
  smaller climate changes like ice ages and El
  Nino/La Nina Mount St. Helens tsunamis and
  hurricanes)
• Humans are making consistent changes throughout
  biosphere, changes that often have ramifications
  toward other changes

3
The Trouble with Humans

• Humans have always altered our environments
• Culture has allowed humans to cover the Earth and
  proliferate
• Since industrial revolution, technology has
  allowed humans greater access to areas,
  resources, longer lives, more lives, etc.
• One change may cause more changes
• Human-caused changes are often interlinked

4
Three Biggest Impacts?

• Global Warming
• Thinning of Stratospheric Ozone
• Exponential Human Population Growth

5
Impacts to the Atmosphere and Earth

• Global warming
• Melting glaciers and ice caps, permafrost
• Average Earth temperature rising
• Effects of species creep
• Weather changes
• As CO2 emissions climb, CO2 sinks decreasing
• Ozone thinning in stratosphere
• Increased UV/damage to plant and animal life and
  productivity

6
Population Growth

• Use and overuse/abuse of resources
• Not always equally used or distributed
• Not always useable after the fact
• Increase of waste products
• Space demands
• Competition for all resources with other species
  and own species

7
General Changes Earth-wide

• Ozone Production in Troposphere
• Effects on health and primary productivity
• Ecosystem fragmentation and destruction
• Katrina effect of wetland destruction and
  coastline development
• New or invasive species introduction
• Direct or indirect introduction
• Reduction of biodiversity
• Overuse of animal resources (e.g., overfishing
  the oceans) and plant resources (grain for people
  or cows?)

8
Impacts on Water Resources

• Global changes to weather patterns/ precipitation
• Pollution to surface waters and groundwater
• Drawdown of groundwater
• Wasting of freshwater

9
Human Additions to Natural Processes
Fig. 32.10
10
More Recent Changes

• Long-term pesticides and residuals
• Effects in the environment
• Technology genetic engineering
• Effects of genetic engineering in the wild?
• Genetically engineered corn spread
• Effects of genetically engineered foods on
  ecosystem communities and humans?

11
All Doom and Gloom?

• Humans beginning to see effects of actions and
  working for global answers
• Some global changes made (e.g., CFCs)
• Stricter laws and regulations in place in
  developed countries
• Human population expected to stabilize
• Inertia and complacency must be overcome

12
On-line Postings

• Journal Question 2 (due 9/12/06)
• Exam 1 (Tuesday, 9/12/06) Needs
• Essay questions for Exam 1 (choose only 1)
• General study guide
• Complete lectures
• Quizzes and answers
• Current Event Paper
• Requirements (including avoidance of plagiarism)
• Sample paper