Figure 3.1 indicates that Carbon dioxide emitted three times as high as Methane in the atmosphere. Also, Carbon dioxide is a leading cause of climate change. Methane ranks 2th followed by Carbon dioxide that has significant effects on climate change. 

2. Discuss what contributions the greenhouse gases described in Figure 3.1 have made to climate change. 

Carbon dioxide, Methane, Nitrous oxide, CFC and ozone in the lower atmosphere are the most leading cause of climate change that affects the quality of the atmosphere. To be specific, Carbon dioxide is the highest production than other medical substances. The nitrous dioxide is the lowest production in the atmosphere. Besides, Methane is maintained twice as high as CFC. On the other hand, the impacts of tropospheric ozone, stratospheric ozone and particles are quite uncertain. 

+  The burning of coal, oil, and natural gas, as well as deforestation and various agricultural and industrial practices, are altering the composition of the atmosphere and contributing to climate change. These human activities have led to increased atmospheric concentrations of a number of greenhouse gases, including carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and ozone in the lower atmosphere. The importance of these gases is shown in Figure 3.1. Carbon dioxide is produced when coal, oil, and natural gas (fossil fuels) are burned to produce energy used for transportation, manufacturing, heating, cooling, electricity generation, and other applications (see Figure 3.2.). The use of fossil fuel currently accounts for 80 to 85% of the carbon dioxide being added to the atmosphere. 

b. Land use changes  = can lead to carbon dioxide emissions 

c. Existing international agreements  = the production of these gases is being eliminated 

d. The tropospheric ozone  = an important contributor to  the enhanced greenhouse effect 

e. The Antarctic ozone hole  = does not cause global warming. 

f. Small particles in the atmosphere  = change the amount of energy that is absorbed and reflected by the atmosphere.

Evidences are extracted from the text:

Evidences:

Cut back on activities such as rice cultivation, cattle and sheep ranching, and by decaying material in landfills; coal mining and oil drilling, gradual transition from industrialization to service industry.

⇒ changes in use fossil fuels and changes in land use.

→ perform existing international agreements.

⇒ Limiting emissions to the environment has a great impact on the greenhouse effect.

These human activities have led to increased atmospheric concentrations of a number of greenhouse gases, including carbon dioxide, methane, nutritious nitrous oxide, chlorofluorocarbons, and ozone in the lower atmosphere. The use of fossil fuel currently accounts for 80 to 85% of the carbon dioxide being added to the atmosphere. Land use changes, e.g., clearing land for logging, ranching, and agriculture, also lead to carbon dioxide emissions. Vegetation contains carbon that is released as be replaced by regrowth with little or no net emission of carbon dioxide. Over the past several hundred years, deforestation and other land use changes in many countries have contributed substantially to atmospheric carbon dioxide increases. Although deforestation is still occuring in some parts of the northern hemisphere, on the whole, regrowth of vegetation in the north appears to be taking some carbon dioxide out of the atmosphere. Land use changes are responsible for 15 to 20% of current carbon dioxide emissions.