Integrated Assessment of Black Carbon and Tropospheric Ozone
Efforts to limit climate change generally focus on reducing carbon dioxide emissions caused by burning fossil fuels. However, another byproduct of fossil fuel combustion is black carbon, a major component of soot. Sources include diesel truck and car engines as well as wood fires, kilns, and stoves. Particles of black carbon in the atmosphere absorb sunlight and can have significant effects on the temperature, as do ozone, methane and other chemicals.
A report jointly authored by the United Nations Environment Program and World Meteorological Organization, “Integrated Assessment of Black Carbon and Tropospheric Ozone” (PDF), analyzed the impact of black carbon and other substances on the atmosphere and modeled predictions for the difference that emissions reduction would have on climate and population health.
The report’s findings include:
- Reducing black carbon and tropospheric ozone will slow the rate of climate change within the first half of this century. Emissions standards for black carbon alone could trim 0.5°C off global temperatures.
- Measures targeting “short-lived climate forcers” such as methane, black carbon and ozone could immediately reduce impacts on public health, water and food security. Black carbon particles contribute to the loss of 50 million tons of crops annually and may lead to as many as 2.5 million premature human deaths a year.
- Even small-scale projects can help significantly reduce black carbon emissions. For example, modifying the design of brick kilns used in Mexico can increase their efficiency by 50% while reducing black carbon emissions by 80%.
While reducing black carbon emissions must be part of the effort to reduce climate change, the authors state that “this assessment does not in any way suggest postponing immediate and aggressive global action on anthropogenic greenhouse gases.” In addition, they note that “the costs and benefits of the identified measures are region specific, and implementation often faces financial, regulatory and institutional barriers.”
Tags: carbon, global warming, greenhouse gases, fossil fuels, coal, pollution, medicine
Note to instructor: The suggested assignments are designed for flexibility. They can be used in whole or part and can be adapted to a particular task -- for example, the newswriting assignments could be applied to the writing of the headline, the lead, the nut graph or the full story. Material from the assignments could also be combined with other material, for example, in the writing of a background, feature or local-angle story.
Read the United Nations Environment Program and World Meteorological Organization study titled "Integrated Assessment of Black Carbon and Tropospheric Ozone" (PDF).
- Summarize the study in fewer than 40 words.
- Express the study's key term(s) in language a lay audience can understand.
- Evaluate the study's limitations. (For example: Do the results conflict with those of other reliable studies? Are there weaknesses in the study's data or research design?)
Read the press release that accompanied the study, "Action to Curb 'Soot' and 'Smog' Pollution Could Help Limit Global Temperature Rise."
- If you had written an article based only on the press release, what would have been its main shortcoming(s)?
Read the study-related Guardian article titled "U.N.: Curbing Black Carbon Would Bring Dramatic, Quick Benefits to All."
- Reporter's use of the study: Evaluate what the reporter chose to include and exclude from the study. Would the audience have acquired a clear understanding of the study's findings and limits from this article?
- Reporter's use of other material: Assess the material in the article that is not derived from the study. (For example: Does the reporter place the study in the context of other research and to what effect? Does the reporter include reactions to the study from other researchers or interested parties [e.g., political groups, business leaders, or community members] and are their credentials or possible biases made clear?)
- Write a lead (or headline or nut graph) based on the study.
- Spend 60 minutes exploring the issue by accessing sources of information other than the study. Write a lead (or headline or nut graph) based on the study but informed by the new information. (Does the new information significantly change what one would write based on the study alone?)
- Interview two sources with a stake in or knowledge of the issue. Be prepared to provide them with a short summary of the study in order to get their response to it. Write a 400-word article about the study incorporating material from the interviews.
- Spend additional time exploring the issue and then write a 1,200-word background article, focusing on major aspects of the issue.