Chapter 4.6, Problem 87PE

Carbon dioxide particles in our atmosphere trap heat and raise the planet’s temperature. Even if all greenhouse-gas emissions miraculously ended today, the planet would continue to warm through the rest of the century because of the amount of carbon we have already added to the atmosphere. Carbon dioxide accounts for about half of global warming. The function

$y=2.5\sin 2\pi x\text{+}0.0216x^2+0.654x+316$

models carbon dioxide concentration, y, in parts per million, where $x=0$ represents January 1960; $x=\frac{1}{12}$, February 1960: $x=\frac{2}{12}$

March 1960; $\dots ,x=1$, January 1961; $x=\frac{13}{12}$, February 1961: and so on. Use a graphing utility to graph the function in a [30, 48, 5] by [310, 420, 5] viewing rectangle. Describe what the graph reveals about carbon dioxide concentration from 1990 through 2008.