Human Influence Biology Fall 2013

Population Growth  Exponential  Modern vs History – what changed?  Only time population went down?  Population Clock Population Clock Population Clock

As Population Increases  Effect on biodiversity

As Population Increases  Need more resources  Habitat loss  Pollution

As Population Increases  Where will they all live?  Urbanization -more people can live in smaller areas

As Population Increases  Deforestation  Loss of habitat  Effect on Carbon cycle?

Climate change  When we burn fossil fuels we add carbon to the atmosphere.  By cutting down trees, we leave carbon in the atmosphere that would be removed by photosynthesis.  This is causing an increase in global temperature called global warming.  Greenhouse Effect- gases such as methane and carbon dioxides blanket the earth and act like a greenhouse to hold in heat.  video video

Natural Environmental Processes  Volcano eruption can cause a decrease in global temperature.  Video Video  Geological processes Geological processes Geological processes

Increased diseases  Effects of density?

Increased Pollution – Acid Rain Release of sulfur dioxide and nitrogen oxides Can be as low as pH = 2 Grandfather Mountain

Hog Farm Waste Lagoons What happens when it floods? Pfiesteria algal blooms

Pesticides  Are insects the only ones affected?  Food chain  Biomagnification

What can we do?  Sustainability  Reduce, Reuse, Recycle