Fire, Climate and Carbon

Dec. 01, 2018
New England Forestry Foundation

Could the Fire That Blackened Paradise Happen in New England?

By Frank Lowenstein

On Monday, the Camp Fire of Northern California was finally contained, having blackened 153,000 acres, destroyed 14,000 homes, and killed at least 85 people. The death toll is likely to rise; more than 200 people in the fire’s path remain missing and unaccounted for. The tragedy is palpable, and the immediacy of social media brought to people around the country and the world the sheer terror of evacuating a landscape lit brightly orange by lurid flaring trees.

Beyond asking what we can do to help the victims (here’s one option for that), there are a variety of other questions that come to mind. Was this unusual? Why did it happen? Could it happen here? And what does it mean for the management of forests?

The answer as to whether the fire was unusual is clear. Yes.

The Camp Fire has killed far more people than any wildfire event in a century. The Cloquet forest fire in Minnesota in October 1918 killed 453, but in an era before modern wild fire fighting techniques and technology. Then there were no air tankers dropping fire retardant chemicals, bulldozers ploughing fire breaks, satellite-informed fire weather forecasts, or elite smoke jumpers arriving by helicopter to intervene at critical moments in a fire’s development.

As to why it occurred, climate change appears to have played a significant role. A simply unprecedented weather context, likely occurring because of climate change, made an event like the Camp Fire a near certainty. The vegetation of northern California was at a record-breaking level of dryness due to persistent elevated temperatures and lack of rain. Historically the probability of such conditions in November would approach zero, but climate change makes such late fall high temperatures and low humidity more likely. This climate-driven dryness then brings fire prone conditions in line with the time frame when California’s famous Santa Anna winds typically peak.

Fire weather specialists measure the likelihood of a fire getting started by a metric called the probability of ignition (PoI): How likely is it that a suitable “fuel”—such as a small branch or leaves—will ignite if a spark hits it? The vicinity of the Camp Fire was at near 100% PoI when the Camp Fire hit. Nearly anything that created a spark could have started the Armageddon that the town of Paradise experienced—a windblown spark from a patio chiminea, a thrown cigarette, an off-road enthusiast’s exhaust pipe striking a rock, or a malfunctioning electric transformer.

Beyond the growing climate-driven risk of fire, the losses of life and property in California and other western states are also accentuated by a pattern of housing development over several decades that has placed homes and businesses into what fire scientists call the wildland-urban interface. When homes are scattered through the forest, with trees close to buildings and wild terrain out the back door, protection of structures during wildfires becomes difficult or even impossible.

This brings us to whether it could happen here in New England. Globally, heat-related sources of tree mortality such as drought and fire are on the rise. In many landscapes this is reducing tree lifespans, and in some as yet rare cases the increasing mortality of trees is causing forests to shift from being carbon “sinks” that remove carbon dioxide from the atmosphere to carbon “sources” that further increase atmospheric carbon dioxide levels. Within this global context, however, New England forests are among the least prone to fire.

There are exceptional places in New England where forest fires are historically common, for example on shallow-to-bedrock soils in the Dogtown region of Cape Ann, Massachusetts, or on sandy soils such as the Ossippee Barrens of New Hampshire. But in most New England forests a shady understory with abundant soggy leaves and damp mosses that hold moisture make the forest floor resistant to a spreading fire. Large wildfires are exceedingly rare.

Nor are most New England tree species adapted to help fires spread. Many Western tree species are adapted to not only readily survive low intensity fires, but also to help fires spread, thereby taking out competitors. The relative absence of such adaptations among New England trees further reduces fire danger.

Of course, in the era of climate change, the past fire resistance of New England’s woods may not be a guarantee, but we are likely to see far fewer fires than many other parts of North America. One key implication is that our forests are likely to remain an important sink for atmospheric carbon dioxide.

We can help do our part to protect global climate by encouraging conservation and wise management of New England’s forests, and particularly by managing for higher carbon stocking per acre in New England forests, for example through growing more mature forests. Applying NEFF’s Exemplary Forestry standards to northern Maine, for example, could sequester hundreds of millions of tons more carbon dioxide in living trees as compared to current forestry practices—equivalent to decades of emissions from the 5 million vehicles owned by New England residents. We can accentuate those benefits by steering forest products from those lands into long-lived products, like cross-laminated timbers that allow us to build tall buildings out of wood, instead of carbon-intensive steel and concrete.