If current trends of burning fossil fuels and deforestation continue, then future amounts of atmospheric carbon dioxide in parts per million (ppm) will increase exponentially. In the year of 1990, there was 353 ppm.

Question

A)In the year of 2000, there was 375 ppm of carbon dioxide, find an exponential function that gives the amount of carbon dioxide, y in year t.
B) Estimate the year when future levels of carbon dioxide will double the initial amount of 353 ppm.

Table:
X side is the years:
1)1990
2)2000
3)2075
4)2175
5)2275
Y side is carbon dioxide ppm:
1)353
2)375
3)590
4)1090
5)2000

Answer 1

just using the first two data points, then in year t since 1990, you have

y = 353 e^(kt), so

353e^(10k) = 375

That gives you k, so then you need to find when e^(kt) = 2