Read the excerpt from "Climate Change: An Overview: This excerpt primarily describes the

By the early twentieth century, carbon emissions from

fossil-fuel burning reached 1 billion tons a year

Automobiles, airplanes, and domestic and agricultural

energy demands all contributed to the rising trend. In

the 1950s, scientists used a new generation of

equipment to confirm that carbon-dioxide

concentrations were doubling and that this would have

the effect of increased temperatures.

long-term effect of increasing carbon emissions.

o long-term effect of decreasing temperatures.

short-term effect of decreasing the use of new

technology

Oshort-term effect of increasing energy demands.