Over the last century, the world has shifted from using high-carbon sources of energy such as wood to lower carbon fuels such as oil and natural gas, as shown in the figure. The rise in carbon emissions during this time has caused concern because of its suspected contribution to global warming.

a. In what year were the percent of wood and coal use equal? What was the percent of each used in that year?

b. In what year were the percent of oil and coal use equal? What was the percent of each used in that year?

Transcribed Image Text:

Share of global energy consumption (percent) 100 80 60 40 20 0000000 Wood Coal Oil Natural gas --- Hydropower -Nuclear 000 0000000 1855 1875 1895 1915 1935 1955 1975 1995 Year