The Earth System Research Laboratory of NOAA

Question 1 [8 points]

The Earth System Research Laboratory of NOAA, a branch of the U.S. government, measures atmospheric greenhouse gas concentrations from stations and aircraft around the world. The famous graph of atmospheric CO2 concentration from atop Mauna Loa in Hawaii (reported in ppm or parts per million), as well as data on annual growth rate (ppm/year), can be found on the NOAA web-site:

Graph back to 1958:

a) What is the annual mean atmospheric CO2 concentration at Mauna Loa for 2010? [1]

b) Using the value from (a), by what percent has the atmospheric CO2 concentration increased from the pre-industrial value of 280 ppm. [1]

% increase of CO2 concentration = (Year 2 CO2 ppm  – Year1 CO2 ppm) / (Year 1 CO2 ppm)  

c) Using the annual mean growth rate data available on this link, calculate the mean or average annual growth rate in ppm/year for the 1960s (1960-1969) and the 2000s (2000-2009).  [2]

d) By what percent did the growth rate change from the 1960-1969 period and the 2000-2009 period? (e.g. 4% increase) [1]

e) Based on the carbon budget discussion in the climate change class, list three carbon flows (inputs) that could explain the change in the growth rate [3]


Question 2 [7 points]

After studying climate observations and the results of global climate models, a group of scientists determined that carbon dioxide-driven global mean temperature change (ΔT) can be roughly estimated directly from cumulative carbon emissions (CE). The calculation uses what they call the “carbon–climate response”, which is equal to ΔT/CE. Their data suggested that the “carbon–climate response” is roughly 0.0015 °C per billion metric tonnes of carbon emitted.

a) Over the past five years, global annual carbon emissions from fossil fuel burning averaged 9 billion metric tonnes of carbon per year. How warming would eventually result from one year of carbon emissions at this rate? [2]

b) The total global carbon emissions from fossil fuel burning since the Industrial Revolution are roughly 383 billion metric tonnes of carbon. How much warming should that generate? [2]

c) What percent of warming should come from carbon emissions within Canada, which is responsible for 7.4 billion metric tonnes of carbon since the Industrial Revolution? [1]

d) the median answer provided in (b) is less than the warming observed to date? Why do you think that is the case? Provide a brief explanation [2]