3this is a multistep problem, and a bit complicated, but it will lead you to your own roughly accurate estimate of the warming from the present level of co2 in the atmosphere.

a) estimate, from the above problem, how much hotter the earth will eventually get if the level of carbon dioxide and other human-made greenhouse gases remain at the present value. you will do this by estimating the increase in temperature due to the part of the natural greenhouse effect which is attributable to co2, and then making an extrapolation to today’s co2 concentration. (for the warming by the natural greenhouse effect, you may use the value i calculated in class, or the value in the book.) co2 itself produces about 20% of the natural greenhouse effect, while the majority is due to water vapor. therefore, if humans raise the co2 level by 5%, for example, we increase the total greenhouse effect by 20% × 5% = 1%. by what percentage have we actually increased co2? use this information to estimate the temperature rise that will follow. i get around 6°f. (this is an increase of about a third as much as the natural warming since the ice ages, so it’s enough to change the planet a lot. and of course the co2 concentration isn’t staying the same, it’s growing, and at a faster and faster pace. finally, we are producing the other greenhouse gases such as methane at alarming rates as well.)

b) why is venus so extremely hot? that is, why is the greenhouse effect so strong on that planet?

( answer both a and b, handwriting is not acceptable)