7.2 Climate Change - Causes & Impacts

Significant Ideas

• Climate change has been a normal feature of the Earth’s history, but human activity has contributed to recent changes.

• There has been significant debate about the causes of climate change.

• Climate change causes widespread and significant impacts on a global scale.

Knowledge & Understanding

• 1. Climate describes how the atmosphere behaves over relatively long periods of time, whereas weather describes the conditions in the atmosphere over a short period of time.

  2. Weather and climate are affected by oceanic and atmospheric circulatory systems.

  3. Human activities are increasing levels of greenhouse gases (GHGs, such as carbon dioxide, methane and water vapour) in the atmosphere, which leads to: (VIDEO)

     1. • an increase in the mean global temperature

        • increased frequency and intensity of extreme weather events

        • the potential for long-term changes in climate and weather patterns

        • rise in sea level.

  4. The potential impacts of climate change may vary from one location to another and may be perceived as either adverse or beneficial. These impacts may include changes in water availability, distribution of biomes and crop growing areas, loss of biodiversity and ecosystem services, coastal inundation, ocean acidification, and damage to human health.

  5. Both negative and positive feedback mechanisms are associated with climate change and may involve very long time lags.

  6. There has been significant debate due to conflicting EVSs surrounding the issue of climate change.

  7. Global climate models are complex and there is a degree of uncertainty regarding the accuracy of their predictions.

Applications & Skills

1. Discuss the feedback mechanisms that would be associated with a change in mean global temperature.

2. Evaluate contrasting viewpoints on the issue of climate change.

Guidance

1. GHGs are those atmospheric gases that absorb infrared radiation, causing global temperatures to be higher than they would otherwise be.

2. Students should be able to distinguish between the natural and the enhanced greenhouse effect and to identify a variety of human activities that contribute to GHG emissions. Students must understand the concept of tipping points and how it might be applied to climate change.

3. A minimum of two different viewpoints should be considered.

Key Vocabulary

• Species

Textbook Reading and/or Activities

Click HERE for a pdf of chapter 4.

• Pages x-xx

  • Challenge Yourself (p.x)

  • Worked Example (p.x-xx)

  • Exercises (p.x)

Notes

i-Biology Notes (Not available)

A detailed set of notes, created by Stephen Taylor, examining U1 - U8 and A1 - A4.

i-Biology Study Questions (Not available)

A series of questions, created by Stephen Taylor, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Bioknowledgy Notes (Not available)

A detailed set of notes, created by Chris Paine, examining all of the IB learning expectations.

Bioknowledgy Study Questions (Not available)

A series of questions, created by Chris Paine, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Learning Activities

Chasing Ice

This video, prepared by National Geographic, will help you better understand the causes and impacts of climate change.

Supplemental Reading

This video, which is a little older, examines the primary causes of climate change and their effects.

This video examines the unfortunate reality that a small percentage of the population is not convinced that global warming is happening despite the overwhelming amount of scientific support. Please note that there is an inappropriate word used at 0:48 of the video.

This video outlines the major historical events that have occurred since 1896 when this issue was first noticed.