Time Period Millions of Years

Temp Change ˚F

Change in CO₂ (ppmv)

Ratio

450 to 440

−23

+249

−10.8

390 to 380

+2

+554

+277

270 to 250

+15

+129.5

+8.6

100 to 90

+7

−294.93

−42

50 to 40

−5

−333

+66.6