10.4 human effects on ecosystems

• how have humans influenced ecosystems?

  • depleted biological organisms - overfishing
  • increased greenhouse gases - climate change and global warming
  • habitat destruction - for construction projects
• global warming


  increase in temperature of earth's atmosphere and surface
• what is evidence for global warming?

  • polar ice melting
  • rising sea levels
  • change in weather
  • coral bleaching
• what is the problem with predictions of global warming?

  • based on extrapolation of data
  • correlation
  • can't establish cause and effect
• what is cites? what are its aims?

  • treaty
  • prevents trade by protecting endangered species by countries signing up to the treaty.
• strengths of CITES

  conserved biodiversity by...

  • limiting trading of animals who are about to be extinct
  • reduced poaching levels
  • increase in number of species
• limitations of CITES

  • not all countries have signed up
  • deals with trade agreements - does't protect ecosystems
  • no legal obligation to abide by CITES
• principles of sustained living

  • maintain biodiversity
  • whilst using for resources
• how can we improve sustainability?

  • reduce carbon dioxide - limit CO2 levels by using biofuels and reforestation
  • converse species - prevent overfishing
• how can you conserve fish stock?

  • sustainable fishing stocks
  • minimise the environmental impact
  • effective management
  • increase awareness of origins and method of fish production
• how was carbon emissions established? issues?

  kyoto protocol - 1992

  issues

  • unfair on underdeveloped countries
  • developed countries would give advantage to others

  compromise

  • carbon credit scheme
• how can evidence be validated?

  • peer review - check for inter rater reliability
  • scientific journals
  • scientific conferences