3/23/15

Tonight's homework is to complete Assignment 60 (hypothesis, graph, and data analysis). Tomorrow we will go over the Mock Exam.

Assignment 60 - Investigating the Effects of a Greenhouse Gas

Introduction

Global climate change is defined as changes in any aspects of the Earth’s climate, including temperature, precipitation, and storm intensity and patterns. This activity will focus on one of those variables: temperature.

Global average temperature has fluctuated over the past 4.7 billion years. Over the past 900,000 years, the troposphere has experienced prolonged periods of global cooling and global warming. Such periods can be caused by a number of factors:

•       Changes in the length of Earth’s elliptical orbit around the Sun every 100,000 years.

•       Changes in the tilt of the Earth’s axis as it rotates around the Sun every 40,000 years.

•       The direction of the tilt of Earth’s axis wobbles with a period of 26,000 years.

•       Changes in outputs of energy by the Sun related to 11-year sunspot and 22-year solar magnetic cycles.

•       Large volcanic eruptions.

•       Changes in levels of greenhouse gases in the troposphere.

The greenhouse effect is a natural process that warms the Earth’s lower troposphere and surface because of greenhouse gases. These gases trap heat reradiated from Earth’s surface and are essential to keep the global average temperature high enough to sustain life. Greenhouse gases include water vapor, carbon dioxide, methane, and nitrous oxide. While these gases have been present in the troposphere throughout Earth’s history, their concentrations have significantly increased since the Industrial Revolution. These increases result from burning fossil fuels, clearing and burning forests, and planting rice and using inorganic fertilizers. Global warming is a warming of the Earth’s atmosphere because of increases in the concentration of one or more greenhouse gases.

Today we are going to investigate the effects of carbon dioxide on a surface’s ability to retain heat.

“Investigating the Effects of a Greenhouse Gas” Analysis Questions

Answer all of the following questions to the best of your ability in complete sentences.

1. Form a hypothesis. How do you think the temperature change will be different when the container is filled with added carbon dioxide compared to when it is filled with just air?

2. Thoroughly analyze your data. This means that you should:

·         Graph your data

·         Make inferences and evaluate your hypothesis

·         Support your conclusions by referring to your data

·         Try to explain what happened 

Resources from Today's Class
Climate change presentation from class today

11BD

Time (minutes)	Temp. (◦C) – added CO2	Temp. (◦C) – no added CO2	Concentration CO2 (ppm) – added CO2	Concentration CO2 (ppm) – no added CO2
0	23	26
5	33	40
10	38	42	1250	1225
15	34	37	9950	1150
20	31	30	9406	1111
25	28	27	6400	1098

12BD

Time (minutes)	Temp. (◦C) – added CO2	Temp. (◦C) – no added CO2	Concentration CO2 (ppm) – added CO2	Concentration CO2 (ppm) – no added CO2
0	53	56	1815	1575
5	40	56	7542	1647
10	32	39	2745	1495
15	29	33	2240	1543
20	28	31	1943	1572