The solution to dangerous, out-of-control wildfires in California is addressing the root cause: “excess fuel load” from bad forest management. Focusing on climate change, a minor variable that we have no near-term control over, is a craven political ploy.
California governor Newsom, while acknowledging some failures in forest management as well, recently put an emphasis on climate change as the main culprit for forest fires in his state.\
“This is a climate damn emergency. This is real and it's happening.”
BBC News, September 12, 2020
The decadally smoothed data from the UK Met Office HadCRUT4 dataset (column 1 contains the year, column 2 the decadally smoothed temperature anomaly data in °C) shows an increase of 0.974°C between 1850 and 2019 globally.
In California the instrumental record goes only back to the year 1895. The Temperature increased by 0.2°F (about 0.1°C) per decade.↩
“Approximately 1.8 million ha burned annually in California prehistorically (pre 1800).”
Stephens et al. (2007) - Prehistoric fire area and emissions from California's forests, woodlands, shrublands, and grasslands https://doi.org/10.1016/j.foreco.2007.06.0051.8 million ha ≈ 4.4 million acres
Between 2010 and 2019 the average annual area burned in California was 775,323 acres, compared to 4.4 million acres estimated for times before 1800, 259,823 acres in 2019, and over 1.2 million acres so far (late August 2020) burned in 2020.↩
China is already the leading emitter of greenhouse gases, at twice the emissions of the US. All reasonable predictions of future emissions anticipate the overwhelming majority of future emissions coming from developing countries that are trying to close the gap in wealth and energy consumption.
The U.S. Energy Information Administration projects that CO2 emissions by non-OECD countries will far outpace US emissions in volume and growth in the coming decades.
U.S. Energy Information Administration - International Energy Outlook 2019
The climate system also shows much inertia, which means any policy, even if effective in reducing global emissions significantly, will take decades to manifest in actual weather averages.↩
Precipitation is estimated to increase with global warming, but regional climate changes can vary by large margins.
“There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. Extreme precipitation events over most of the midlatitude land masses and over wet tropical regions will very likely become more intense and more frequent”
IPCC Special Report Climate Change and Land, chapter 2 p. 137
In California no trend has manifested with regard to precipitation in the annual data since 1895.↩
The Palmer drought severity index shows an increase in drought severity since the late 19th century with particularly wet episodes during the early 1980s and 1990s.↩
It is difficult to separate any human impact on a particular fire season from the natural noise that the California climate experiences every year. Before the modern records began in the 19th century, California naturally experienced so-called megadroughts that could last over a century. The 20th century has been a very lush period in comparison.
Climate impacts on California fires are also complex. Dryness leads to more easily ignited vegetation in the short term but less vegetation over time, while more rainfall reduces the short-term risk of fires while creating more biomass for future fires during a dry period. Continued warming will likely increase drought danger in California but also increase precipitation and influence dynamics of the Pacific ocean, which affect California’s climate.
Any climate impact from human causes that could negatively impact the fires is relatively slow moving compared to the increasing settlement of humans, which causes more fire ignitions from accidents and arsonry and choices of forest management policies. More importantly, any climate policy to slow or reverse such impact, if it was effective at all, would take many decades to make even a small difference.
The two most important variables in wildfires, ignition by humans and availability of dry vegetation or “fuel load” are under human control.
U.S. Geological Survey - 2012-2016 California Drought: Historical Perspective
“The past 150 years have been unusually wet when viewed over the past 2000 years, so the 20th century was a wetter century, and this is when all of our water development, population growth and agricultural industry were established, and so it’s possible the climate may now be shifting to a drier regime” Lynn Ingram, professor of Earth and Planetary Science at UC Berkeley in 2014↩
California’s San Onofre nuclear power plant was shut down in 2013 despite only requiring the replacement of a steam generator for less than $700 million.
Mark Nelson and Minshu Deng - California Nuclear Closures Resulted in 250% Higher Emissions from Electricity, Environmentalprogress.com
The state’s last remaining nuclear power plant, Diablo Canyon, will shut down by the mid 2020s.
Regulators vote to shut down Diablo Canyon, California’s last nuclear power plant - Los Angeles Times
Between 2014 and 2019 California has increased the share of solar and wind on its electricity grid from over 12% to over 26% (or by over 25 terawatt hours annually).
California Energy Commission 2014 Total Electricity System Power