These data and graphs are from Raupach et al. (2007) in the journal, Proceedings of the National Academy of Science. The researchers were investigating the question, how do actual carbon dioxide emissions compare to modeled projections? Both graphs show multiple model predictions for increases in carbon dioxide emissions as gigatons of carbon per year. The bottom graph differs from the top graph mainly with respect to time and focuses in on a twenty year period from 1990 to 2010. The colored lines on the graph show multiple carbon dioxide emissions scenarios including what happens if global economies were to stabilize at certain emission rates. The black lines represent what is actually occurring – that is the actual rate of carbon dioxide emissions. The big take-home message from these data is that current rate of carbon dioxide emissions is higher than even the highest modeled projection.
*** Look at: http://co2now.org for current and monthly atmospheric carbon dioxide levels. ***
1.Have students research the different emissions scenarios (http://www.ipcc-data.org/ddc_co2.html). Have students discuss how scenarios were estimated, their key assumptions and any other unique features.
2.Have students research the differences between the CDIAC and EIA actual emission measurements. How are the techniques different and could this explain why they produce slightly different measurement.
3.It should also be pointed out to students that even stabilization will continue to increase global carbon emissions. After pointing out this trend to students, students should work in small groups and brainstorm solutions to this problem***. How could countries, economies, and communities work at small and large scales to create carbon reservoirs to pull carbon from the atmosphere? This exercise would be an opportunity for students to think both critically and creatively using their knowledge of biological and environmental processes.
4.Have students brainstorm or make concept maps about the differing perspectives of climate change and how different worldviews can influence our actions, policies, and solutions.
***A possible prompt for students is that there are two general solution pathways: reduction and geoengineering. These two general headings could be used in a pro/con type set-up and students should also be encouraged to discuss the social, economic and environmental components of each of their ideas.***