natural climate change

11/9/12

❖ Xtranormal due today

❖ Project due Tomorrow

❖ Unit 6 Quizlet due Tuesday 11/20

❖ Be checking your grades

❖ Weekly Reporter

Review

❖ Explain the difference between weather and climate.

❖ Compare and contrast the major types of climate as described by the Koeppen system.

Objectives

❖ Describe natural processes that can affect earth’s climate.

❖ Understand the causes and effects of El Nino.

Question

❖ How do natural processes affect climate?

Climate Change

❖ Think: What have you heard about climate change?

❖ Pair

❖ Share

Climate Changes

❖ Natural changes in the Earth’s climate can be broken into two categories

❖ Short-term changes

❖ Long-term changes

Long-term changes

❖ Types of long-term climate changes

❖ Ice Ages

❖ Solar Activity

❖ Earth’s Orbit

Long-term changes❖ Ice Ages

❖ What is an ice age?

❖ Periods of time where glaciers cover large parts of Earth’s surface

❖ Earth alternates between ice ages (glacial periods) and warm periods (interglacial periods)

Long-term changes

❖ Ice Ages

❖ Last ice age ended 10,000 years ago

❖ Ice stretched as far south as Indiana

❖ Earth was on average 5 degrees C cooler

Long-term changes

❖ Solar Activity

❖ Periods of high activity have been connected to warmer temperatures on Earth

Long-term changes

❖ Earth’s Orbit

❖ Scientists believe that every 100,000 years the orbit of the Earth changes shape

❖ Brings the Earth closer to or further from the Sun

Short-term changes

❖ Short-term climate changes

❖ Seasons

❖ Volcanoes

❖ El Nino

Short-term changes

❖ Seasons

❖ I’m going to assume that you have this one

❖ Any questions about how a season is a short-term change?

Short-term changes

❖ Volcanoes

❖ How would the eruption of a volcano affect the Earth’s climate?

Short-term changes

❖ Volcanoes

❖ Eruptions release dust, smoke, and ash

❖ What do you think those things do to the amount of sunlight that reaches Earth?

Short-term changes

❖ Volcanoes

❖ Dust and ash released from a volcano blocks incoming sunlight

❖ Cooler temperatures on Earth have been connected to big volcanic eruptions

Short-term changes

❖ El Nino

❖ A short-term change in the water temperature of the Pacific Ocean

Short-term changes

❖ El Nino

❖ Normally winds push warm surface water towards Australia

❖ Because warm water is pushed away, cold water can rise near South America

❖ Fish like cold water

Short-term changes❖ El Nino

❖ Occasionally the winds switch direction

❖ Warm water gets pushed to South America

❖ Fish don’t like warm water

❖ Hurts the fishing industry

Short-term changes

❖ Effects of El Nino

❖ More rain and storms across South America

❖ Drought conditions in Australia and the South Pacific

❖ Stronger hurricane season in the Atlantic