Line 1.0.0 The furnaces of the world are now

Line 1.0.1 burning about 2,000,000,000 tons of

Line 1.0.2 coal a year. When this is burned,

Line 1.0.3 uniting with oxygen, it adds about

Line 1.0.4 7,000,000,000 tons of carbon dioxide

Line 1.0.5 to the atmosphere yearly. This tends

Line 1.0.6 to make the air a more effective blan-

Line 1.0.7 ket for the earth and to raise its

Line 1.0.8 temperature. The effect may be con-