Humans in the Biosphere (Chapter 6)Please set up your notebook for Cornell Notes

Human activities that impact the biosphereHunting and gathering

Hunt animals for food, gathered plant matterThe arrival of humans in North America 12,000 years ago caused the extinction of many large mammals

Agriculture farmingProvided a dependent source of foodLead to the development of larger communitiesAdvances in techniques lead to crops being grown in new areasMonoculture large fields planted w/ one type of plant

Chemical fertilizers and pesticides are used to increase yieldThe chemicals can run off and affect water supplies

Green revolution evolution of modern techniques that increased world’s food supplyHow can we keep humans fed w/ less impact on the planet?

Industrial growth and urban developmentIncrease in pollution and wasteWhat do we do with all of our trash?How can we limit pollution?

BiodiversityBiodiversity the variety of all life on the planet

Ecosystem biodiversity all the habitats, communities and ecological processes in the worldSpecies Diversity the number of different species in the biosphere

Also called species richnessHighest near the equator, lowest near the poles

All organisms in the biosphere are linked

Threats to biodiversityHuman activity can reduce biodiversity by altering habitats, hunting species to extinction, polluting and introducing foreign species into the environment

Some of these activities lead to extinctionSpecies that are at risk of going extinct are considered endangered

Foreign species that reproduce quickly and threaten native species are called invasive speciesConservation wise use of natural resources, including preserving habitats and wildlife

Global Climate ChangeGases in atmosphere help trap heat from the sun much like a green house called green house effect

Necessary for lifeEvidence of global warming

Geological record shows Earth’s climate has changed repeatedly in history

How have how human activities contributed to climate change?Increasing levels of CO2 in the atmosphere

Possible effects of global climate changeIncrease in average global temperature 1-2 CCould cause flooding of coastal areas as ice caps meltIncreases in extreme weather

Drought, snow, hurricanesExtinction of organisms that cannot adapt to new, higher temps.