Why do the leaves of plants change color and fall in the autumn?

What is hibernation and why do some animals engage in it? What types of animals, generally, hibernate?

Think about it…

Climate Change

First image of earth from space.Taken by Jim Lovell aboard Apollo 8 on

12/24/68.

Weather is the daily condition of Earth’s atmosphere at a particular place and time.

Climate is the average yearly conditions of temperature and precipitation in a region.

Climate is caused by:Trapping of heat in the atmosphereLatitudeTransport of heat by winds and ocean currentsAmount of precipitationShape and elevation of landmasses

Weather and Climate

The greenhouse gases are atmospheric gases that trap infrared radiation (heat energy) that has been reflected off the Earth’s surface thus maintaining Earth’s temperature range.

The natural event in which heat is retained by this layer of greenhouse gases is called the greenhouse effect.

The Greenhouse Effect

Sunlight

Earth’s Surface

Atmosphere

Some heat escapes into space

Greenhouse gases trap some heat

Greenhouse gases trap some heat

Could we survive without the greenhouse effect?No, Earth would be too cold for many organisms to

survive, including human beings.Can you name any greenhouse gases?

Think about cycles of matter…Water Vapor – evaporation (water cycle)Carbon Dioxide (CO2) – burning fossil fuels,

deforestation, volcanic eruptionsMethane (CH4) – decomposition/decay, livestock

wasteNitrous Oxide (N2O) – fertilizer, fossil fuels,

denitrificationSynthetic gases (e.g. CFCs) – industrial processes

The Greenhouse Effect

Remember from our last class that carbon dioxide is released from a variety of sources. A major contributor to atmospheric CO2 is human activity.

Levels of CO2 in the atmosphere have risen dramatically sense the advent of the industrial revolution.Why do you think this is the case?

In 1850, just before the industrial revolution the [CO2] in the atmosphere is estimated at about 274 ppm.

In August 2015, the [CO2] in the atmosphere was over 398.820 ppm.

Atmospheric Carbon Dioxide

What do you think are some potential effects of increased CO2 in the atmosphere?

Atmospheric Carbon Dioxide

Some potential effects of increased [CO2] could be:Increased growth/productivity by vegetation

(increased levels of photosynthesis). Why? C3 plants (rice, wheat, soybeans) are more

limited by CO2 availability than C4 plants (sugarcane, corn) so C3 plants may spread into C4 areas.

A link between increased CO2 and increased temperature exists. So when [CO2] rises, temperature rises. Why?

What are some potential results, globally and locally, from rising temperatures?

Atmospheric Carbon Dioxide

The Holocene Extinction is the present, widespread, ongoing extinction during the current Holocene Epoch.

This is the Sixth Great Extinction, the largest since the one that killed off the last of the terrestrial dinosaurs.

The Holocene Extinction has been going on since about 11,000 BCE and has been attributed to anthropogenic causes by a majority of biologists.

Human-induced climate change, overexploitation, deforestation, and the introduction of non-native species may have all played a role.

Holocene Extinction

Because all species are interdependent upon one another, what is the potential impact of losing any one species?

The brazil nut, the tree from which the name of the edible nut is derived, is one of the most massive and important trees in the Amazon.

Only one creature, a rodent called the Agouti, can crack the shell, thus allowing the tree to reproduce.

Video: http://www.arkive.org/brazil-nut-tree/bertholletia-excelsa/video-11.html

Video: http://www.youtube.com/watch?v=HURyGlOksR0

Importance of Diversity

The polar bear is listed as threatened. It is considered a vulnerable species.

Habitat loss is the main threat to polar bears.

It was the first species to be listed as threatened due to global warming.

Polar Bear (Ursus maritimus)

There are literally thousands of examples of species’ interdependence.

Many flowers have evolved to be dependent upon insects for pollination.Can you think of an example?

The Holocene Extinction is generally thought to have begun with the extinction of the megafauna at the end of the last Ice Age.

Many of these species were hunted to extinction, while others lost their sources of food due to human overexploitation.

Interdependence

The Wooly mammoth (Mammuthus primigenius)

The theory of its extinction is controversial.

Most scientists believe it was due to climate change, overhunting, or a combination of the two.

Megafauna

The Saber-toothed Cat (Smilodon populator)

Extinction causes thought to be similar to mammoth’s.

Likely due to overhunting by humans.

Megafauna

Baiji (Lipotes vexillifer)

Freshwater river dolphin from China

‘Effectively Extinct’ 2006

Caused by humans: pollution in rivers, habitat destruction (dams), fishing, collisions with boats.

Recent Extinctions

Javan Tiger (Panthera tigris sondaica)

Subspecies of tiger on Indonesian island of Java.

Extinct in 1980s due to hunting and habitat destruction.

Recent Extinctions

If trends continue, what species will most likely survive? Why?

If trends continue, what species will most likely go extinct? Why?

How is this related to global climate change?

Holocene Extinction