The California fires are a climate-driven catastrophe

In recent months, California has broken all the wrong records as major wildfire after major wildfire has ripped up and down the coastal state. As fall winds down in California, hot and dry conditions typically give way to cooler temperatures, more moisture, and scattered showers, thus putting an end to the long fire season. However, in recent years, and even decades, that trend has faded.

This past October, California experienced the most destructive wildfire in the state’s recorded history, claiming over 5,600 structures and 22 lives. Not two months later, yet another major blaze — the Thomas Fire — became the fifth largest on record in the state, having already scorched some 230,000 acres and still burning. The fire is now the largest December wildfire in California’s history.

{mosads}As both an air pollution scientist and California native, these wildfires concern me greatly. Not just because of the impacts to air quality and health. And not just due to the scorched earth and wreckage of the aftermath.

But because there may be no end in sight. Based on the U.S. National Climatic Data Center, average temperatures in California have been steadily increasing since the early 1900s. As drought conditions become more frequent and vegetation more dry, the risk of major wildfires will only grow.

According to a 2006 study of wildfires in the western U.S., recent decades have seen a four-fold increase in major wildfires, compared to the period from 1970 to 1986. The area burned by such fires has increased a staggering six-fold.

Amidst the roaring Thomas Fire in Ventura County this month, California Governor Jerry Brown called this the “new normal,” echoing the words of climate scientists around the world. That is, increased temperatures, droughts, and wildfires are not separate from the issue of climate change, and will likely continue as we move forward.

In its latest report, the Intergovernmental Panel on Climate Change speaks of future “decreases in winter precipitation over the southwestern USA” associated with the “expansion of subtropical arid regions.” Complementary findings by a U.S. Forest Service study in 2103 concluded that “fire potential is expected to increase in the Southwest…and Pacific coast, mainly caused by future warming trends.”

This year’s numbers certainly support such projections. According to the California Department of Forestry and Fire Protection, five of the state’s twenty most destructive wildfires occurred within just the last three months of 2017 — the most destructive being the TUBBS Fire in Sonoma County that occurred earlier this fall. And it’s not just California.

The neighboring states of Oregon, Washington, and even Canada have experienced similar warming trends, with accompanied increases in major wildfires. Of the ten largest wildfires on record in Oregon, four occurred in just the last five years. These facts are startling and warrant our attention.

Observed increases in fire activity are arising from four interrelated factors linked to climate change; namely, earlier snowmelt, higher summer temperatures, a longer fire season, and an increase in vulnerable areas such as high-elevation forests. That is, as climate change brings about higher temperatures in the West, snow melts earlier in the season.

Such snow is essential to feeding creeks and streams, which in turn keeps landscapes moist and green through much of summer. As snow melts earlier, vegetation dries sooner, becoming flammable earlier in the season. Coupled with rising summertime temperatures, this makes for a longer fire season.

According to the 2006 study above, the western U.S. now experiences a 78 day longer wildfire season, with the average burn duration having increased from 7.5 to 37.1 days, compared to the period before 1986.

It only compounds the situation when we consider that previously inflammable high-elevation regions are now becoming vulnerable to fires as temperatures rise. Altogether, this sets the stage for a perfect fire storm, and perhaps a new reality for the West.

Growing temperatures are related to long term changes in the climate — largely attributable to a family of heat-trapping pollutants with which we’ve all become familiar; namely, greenhouse gases, or so called carbon pollution.

With each passing year, the U.S. continues to be a global leader in carbon emissions. It is time for the U.S. to curb such emissions and instead join other nations by becoming a global leader in renewable energy production and climate solutions.

For years, economists have supported a carbon tax to achieve this aim. Taking the added step of redistributing tax revenue back to the population would likely earn more public support, and has been endorsed by both Democrats and Republicans alike.

Two well-known iterations of such a plan have been articulated by the nonpartisan Citizens’ Climate Lobby as well as the recently published Conservative Case for Carbon Dividends. Congress must give serious consideration to such proposals.

A bill that offers a path to carbon reductions while stimulating job growth in the renewable energy and energy efficiency sectors would be widely popular, and is imperative.

Meanwhile, the public must remain active in the pursuit for climate action by communicating with representatives in Washington and supporting strong steps towards such aims.

Shahir Masri, is an assistant specialist in air pollution exposure assessment and epidemiology at the University of California at Irvine, and also teaches at the Schmid College of Science and Technology at Chapman University. He earned his doctor of science and master of science degrees from the Department of Environmental Health at the Harvard T.H. Chan School of Public Health.