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Classroom Resources: Black is the New Green

Black is the New Green

By Carl Zimmer

July-September 2010/ Vol. 11 No. 3

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Discussion Questions

1.     This article has to do with global warming and solutions for interrupting the carbon cycle to store more in the soil. To better understand the article one needs to answer these questions:

a.     What causes the Earth’s climate to change? Is climate change natural? How have humans influenced climate in recent times? What role does carbon play in anthropogenic global climate change? What are some current sources of carbon in the atmosphere?

b.     What is pyrolysis? Why does it not emit as much carbon into the atmosphere as regular burning?

c.     How do plants exchange carbon with the atmosphere through respiration and photosynthesis?

d.     What is meant by “climate mitigation” and “climate adaptation”?

2.     What inspired Johannes Lehmann to investigate putting waste organic matter back into the soil? What natural history/cultural history observations did he make in the field that led him to develop a theory and testable hypotheses? In the larger sense, does science rely upon such qualitative observations in the field or is most of it done via experimentation?

3.     Explain the production of biochar and how it can help with global warming and also with human health in the developing world. Be specific – what is biochar? Why does biochar reduce carbon emissions from biomass?

4.     How can it help mitigate global climate change? What is it about pyrolysis that makes using it to cook with so much better for human health?

5.     If ancient Amazonians were smart and could figure out how to produce terra preta and it took a Cornell scientist thousands of years later to understand it, why is our highly technological, scientifically advanced civilization so slow to adopt it? Along those lines, what happened to those ancient civilizations and is there more we can learn both from their successes and evident failures?

Websites for Further Information

Biochar in the News

Peer-reviewed Literature (in addition to the citations listed in the article)

  • Lal, R. et al. 2004. Soil carbon sequestration impacts on global climate change and food security. Science 304:1623-1627.
  • Lehmann, J. et al. 2006. Bio-char sequestration in terrestrial ecosystems—a review. Mitigation and Adaptation Strategies for Global Change 11:403–427.

Key Concepts

  • Global warming
  • Climate change
  • Biochar
  • Charcoal
  • Soil
  • Carbon sequestration
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