Your “Do Now” 5/25

• Take ½ sheet of paper• Write down 5 things you remember from the

visit by the GVSU scientists yesterday

What are we studying now?

• We looked at how energy and matter cycle through an ecosystem

• Then we saw how organisms are all interconnected by food webs

• Now we’re looking at how human activities can disrupt ecosystems / food webs!– Starting with Global Warming

CH 16 Learning Target #1

1) I can explain the causes and effects of global warming and why it’s important to research

Greenhouse effect• Greenhouse effect: the warming that happens

when certain gases in Earth's atmosphere trap heat.

Greenhouse gases: Gases in the Earth’s atmosphere that trap heat

• Examples: Carbon dioxide (CO2), water vapor (H2O) and methane (CH4)

• The greenhouse effect is natural!

Without the greenhouse effect, Earth would be much colder and life as we know it could not exist

Global Warming (Climate Change)• For the past few thousand years, Earth’s

temperatures and greenhouse gases have stayed pretty much constant (same)

• Over the past 150 years the Earth’s average temperature has been increasing rapidly from burning fossil fuels.

• Global Warming: increase in the average global temperature over time – Eleven of the twelve hottest years recorded were

between 1995 and 2006!

• Our main concern: adding more CO2 will keep increasing temperatures

Evidence of Global Warming

• Temperature measurements from satellites, thermometers, ice core samples, and other sources all show warming trends over past 150 years

• Plants and animals are changing• Ex: plants are getting leaves earlier, some

animals are migrating differently

• Glaciers are melting and sea ice is decreasing

http://www.youtube.com/watch?v=Nngm2TFF9uo

• Other causes have been ruled out (sun, earth’s orbit, etc.)

Warming caused by humans vs natural causes

• Earth’s temperature changes naturally over time, but burning fossil fuels is doing this much faster

Large changes usually take thousands of years, but are now happening over decades!

Why global warming is a problem• Climate is changing faster than some organisms

can keep up with– lots of organisms could become endangered or extinct!

Earth's ice sheets (such as Greenland and Antarctica) are start to melt– Sea levels could rise, causing flooding and

destruction of cities/habitats

• Weather will become more extreme, causing more damage to cities and ecosystems

This means more damage from droughts, floods, and hurricanes

Global warming in Michigan

• 2009 study showed small some small mammal species are moving north as temps. Increase

• Insects that affect crops are moving north too

• Changes to come:– Decreases in crop yields (losing money)– Warmer summers & winters– Changes in lake-effect snow– More harmful algal blooms

Complete your research online

• Fill in last 2 parts on your notes too!

Scientists know that global warming is happening. The question now is: how bad will it be?

• Which species will die-out?• How will people be affected by droughts &

floods?• How will we prepare for a future with a

different climate?• How will we prevent or reduce the effects of

global warming?

Possible solutions

• Alternative energy sources: reducing fossil fuel use

• Efficient vehicles & factories to reduce energy use

• Use less energy (conservation)