Which of the following statements is true about the temperature of the Earth’s surface? a. The Earth’s surface has warmed by 1 degree Celsius in the last year

b. The Earth’s surface has cooled by 1 degree Celsius in the last year

c. The Earth’s surface has warmed by 15 degrees Celsius in the last 100 years

d. The Earth’s surface has warmed by 1 degree Celsius in the last 150 years