Long-term Perspective on Wildfires in the Western USA
As Anglo-American settlers moved across North America, they had a significant impact on the land, clearing trees, expanding agriculture and building towns. As settlement expanded, forest fires — once an integral part of the natural world — were systematically suppressed. This practice had consequences when fires did break out, as they seemed to be increasingly large and severe.
In recent decades, Western wildfires have become larger and more severe, and scientists note that this is often related to accumulated materials — fuel loads — that, historically, have been burned in smaller blazes. Indeed, the combination of human suppression and changes in climate could make for an increasingly volatile mix in the coming years, and there remains continuing debate over best practices for forest management in this regard.
To better understand long-term variations in wildfires in the American West, a group of researchers looked at 3,000 years of sedimentary charcoal accumulation rates — obtained from the Global Palaeofire Working Group at the University of Bristol, U.K. — and matched them to fire scars and historical accounts of blazes. The results of the 2012 study, “Long-term Perspective on Wildfires in the Western USA,” were published in the journal Proceedings of the National Academy of Sciences.
The area studied includes the U.S. states of Washington, Oregon, California, Idaho, Nevada, Montana, Wyoming, Colorado, New Mexico and Arizona.
Key findings include:
- Burning in the American West declined slightly over the past 3,000 years, with low levels between 1400 and 1700 CE and throughout the 20th century. Peaks in burning occurred between 950 and 1250 CE and then again during the 1800s CE.
- Fire activity was historically highest at 1000, 1400 and 1800 CE. The rise in fires at 1000 CE occurred when temperatures high and drought area were widespread. Another increase in fires occurred at around 1400 CE, when drought conditions increased rapidly.
- Humans began to have a significant impact on fires in the 1800s. During expansion of Anglo-American settlements in the 19th century, evidence of burnings increased. In the 20th century this is reversed, due in part to changing practices nationally in fire outbreak management. Since then, “fire activity has strongly diverged from the trend predicted by climate alone and current levels of fire activity are clearly out of equilibrium with contemporary climate conditions.”
- Burning is currently at its lowest in history. The previous minimum was between 1440 and 1700 CE, and was due to a decrease in droughts and temperatures, which were at a 1,500-year minimum. Prior to the current era, fire reached its lowest historical level at 1500 CE, which corresponded with the collapse of several Native American populations.
The authors of the paper conclude: “The divergence in fire and climate since the mid 1800s CE has created a fire deficit in the West that is jointly attributable to human activities and climate change and unsustainable given the current trajectory of climate change.”
Tags: California, global warming, disasters
Read the issue-related Denver Post article titled “Colorado Crews to Continue Fight Against 3,000-acre Fire Near Aspen Park Overnight.”
- What key insights from the study should reporters be aware of as they cover these issues?
Read the full study titled “Long-term Perspective on Wildfires in the Western USA.”
- What are the study's key technical term(s)? Which ones need to be put into language a lay audience can understand?
- Do the study’s authors put the research into context and show how they are advancing the state of knowledge about the subject? If so, what did the previous research indicate?
- What is the study’s research method? If there are statistical results, how did the scholars arrive at them?
- Evaluate the study's limitations. (For example, are there weaknesses in the study's data or research design?)
- How could the findings be misreported or misinterpreted by a reporter? In other words, what are the difficulties in conveying the data accurately? Give an example of a faulty headline or story lead.
Newswriting and digital reporting assignments
- Write a lead, 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?
- Compose two Twitter messages of 140 characters or fewer accurately conveying the study’s findings to a general audience. Make sure to use appropriate hashtags.
- Choose several key quotations from the study and show how they would be set up and used in a brief blog post.
- Map out the structure for a 60-second video segment about the study. What combination of study findings and visual aids could be used?
- Find pictures and graphics that might run with a story about the study. If appropriate, also find two related videos to embed in an online posting. Be sure to evaluate the credibility and appropriateness of any materials you would aggregate and repurpose.
Class discussion questions
- What is the study’s most important finding?
- Would members of the public intuitively understand the study’s findings? If not, what would be the most effective way to relate them?
- What kinds of knowledgeable sources you would interview to report the study in context?
- How could the study be “localized” and shown to have community implications?
- How might the study be explained through the stories of representative individuals? What kinds of people might a reporter feature to make such a story about the study come alive?
- What sorts of stories might be generated out of secondary information or ideas discussed in the study?