earth’s cycles and climate change… woohooo !

EW: What major events did you see on other peers timelines?

Were there any patterns between different time periods

that you saw?

Earth’s Cycles and Climate Change…woohooo!

What patterns of major events did you see amongst the timelines?

Examples could be:

-Mass extinctions of animals-Ice ages-Climate changes-Continents moving (plate tectonics)-Different chemical compositions of atmosphere: Why is this?

18.1 The geologic time scale

• Divided into blocks of time called eons, eras, periods and epochs.

• Geologic time scale-shows geologic differences amongst time periods

• Earth is about 4.6 billion years old

Earth’s Changing Past and Future• 4.6 billion years ago to 542 million years ago= 88% of Earth’s history

– Atmosphere formed from volcanoes and water vapor– Oceans formed then first cells!

• Plants and cells that were able to capture sunlight and use it for energy….. gave rise to an increase in oxygen in our atmosphere!– Why is that?– Cambrian explosion! (542 million years ago)

• Many new life forms became into existence • Huge amounts of fossils from this time period!

• Pangea=large super continent about 250 millions of years ago.

18.1 Mass extinction

• Scientists have evidence that a large asteroid crashed near Mexico’s Yucatan peninsula about 65 mya.

• The resulting climate change may have caused the extinction of Mesozoic Era reptiles, including most dinosaurs.

18.1 Evidence of major events or age of organisms! We can use Trees

and absolute dating

• Trees are like history books. • Each tree ring is a record of what the environment was like

that year.• Wide tree rings=very wet year and narrow rings=dry year. • Absolute dating=real age of a sample ( example: fossils) – Radiometric dating=measures change of elements in

rocks, minerals and fossils

18.2 Law of superposition and principle of fossil succession

• law of superposition, which states that the bottom layer of a rock formation is older than the layer on top.

• Fossil succession: The organisms found in the top layers appeared after the organisms found in the layers below them.

18.3 Rocks keep moving

• Rock cycle includes weathering and erosion of all different type of rocks through different natural processes

• Plate tectonics— plays an important role in the rock cycle.

15.1 Chemical Cycles

• The Earth’s elements essential for living things are called nutrients.

11.1 Photosynthesis and the atmosphere

• Photosynthesis converts carbon dioxide to oxygen and glucose in a process that allows living things to use the sun’s energy.

15.1 The carbon cycleCarbon is an important element on earth and in our atmosphere! -Where did carbon come from?

11.2 The tilt of the earth causes different climates

• At the equator, sunlight is direct and intense.

• As a result, the average yearly temperature at the equator is 27 °C (80 °F), while at the North Pole it is -18 °C (0 °F).

15.2 Global climate change

• Global climate change refers to changes in climate such as temperature, precipitation, or wind that last for two or more decades.

• Climate=differences in temperature, precipitation (rain,snow) or wind

15.2 The greenhouse effect

• Gases in our atmosphere: Nitrogen, Oxygen, Argon, CO2

• The greenhouse effect is the warming of Earth that results when Greenhouse gases trap heat:

• water vapor, carbon dioxide, methane, nitrous oxide, ozone, and carbon compounds produced by industry.

97% of scientists agree

• CURRENT Global warming is human caused and real.

• You will be reading about different solutions tonight for homework and answer questions to participate in BINGO tomorrow!

Other information beyond this slide

FYI – oldest plants

• The oldest tree on record is a bristlecone pine called “Methuselah.”

• It is 4,765 years old. • Gallery• Ted Talk – oldest living org

anisms

11.1 Why is Earth different?

Photosynthesis changed Earth’s atmosphere.

18.1 Paleozoic era

• Lasted from 542 to 251 mya.

• Which time period did you have?

18.1 Mesozoic era

• Lasted from 251 to 65 mya (AKA the Age of Reptiles.)

• Large Dinosaurs!

18.1 Cenozoic era

• Began 65 mya and is still going on (AKA the Age of Mammals).

• Which time period did you have?