Question Description

There are currently (as of June 2017) 409 parts per million of CO2 in our atmosphere. In Oct 2000 the concentration of CO2 was 367 ppm.

a) calculate the average growth rate in this period

b) at this growth rate what will the concentration of CO2 in the year 2100.

A reasonable approximation of the amount of surface temperature (in degrees C) increase as related to CO2 concentration is given by:

ΔT = 0.8 * ΔF

where for CO2

ΔF = 5.35 * LN(Cnow/Cbefore); Cbefore = 280 ppm

Note that LN stands for the natural logarithm; for instance ln(10) = 2.32 (just type ln 10 in to Google)

ΔF represents the change in flux due to changing CO2 levels and that determines ΔT

c) Using the result obtained in Part b, what is the predicted temperature change in the year 2100 and is this prediction above or still below the Paris accord agreement of no more than 2C before 2100 above the pre-industrialized temperature?

Over the last two years, CO2 growth is occurring at a larger rate than the recent average. This rate is approximately 0.8% per year and is likely to continue to accelerate. Any change in temperature (given by the previous formula) that is larger than 4C is deemed to be a climate catastrophe and completely violates the Paris Accord:

The US and China are the only relevant players in this acceleration which leads to the two scenarios below:

Scenario 1: China abruptly halts its emission of green house gases Out to the year 2100 the US growth rate will be 1.1% per year as we burn our remaining coal and frack our remaining gas and continue to drive excessively.

e) Under that scenario, what is the year that US only emissions drive us past the +4C mark?

Scenario 2: The party of enlightenment is voted into office as the Trump alternative in 2020 and immediately halts US emission of greenhouse gases. Now only China matters. Out to the year 2100 the China growth rate will be 1.8% per year as they feverishly emulate the US but at a much larger scale.

f) Under that scenario, what is the year that Chinese only emissions drive us past the +4C mark?