Fire: The Climate Connection – September 30, 2020
As we’ve gathered more data and evidence these last few years on the global impacts of climate change, a new field has emerged: extreme-event attribution, which investigates if and to what extent climate change contributes to the frequency and severity of extreme events, such as super-storms (hurricanes) and raging hot wildfires. Read more here: https://www.cell.com/one…/fulltext/S2590-3322(20)30247-5
It is important to understand the interplay of variables in extreme weather, as this affects how we plan for the future, how we reduce risk, and how we adapt. It is important to acknowledge natural variability in the Earth system (like El Niño/La Niña) and policy decisions related to wildfire and land management. However, putting blame on the extreme wildfires we’ve been seeing in the US this season simply to poor land management and arson is misleading.
California is currently experiencing its worst fire season on record – and the season is still not over. What led to this? The state experienced some of the highest “vapor pressure deficit”- the difference between how much moisture the air can hold versus how much moisture there is – in decades. The higher the deficit, the drier the air is, meaning the air can suck out moisture from vegetation instead to quench its “thirst.” Record-breaking heat, drought, and this high deficit has baked the state, turning its forests and shrubs into easy-to-light tinder. Add wind and you have a set-up for disaster. Research into Australia’s massive bushfires last year found that climate change increased the likelihood of conditions that fueled the fires by at least 30% (https://www.worldweatherattribution.org/…/WWA… ). In Arizona and New Mexico between 1984 and 2015, a study found that climate change is increasing wildfires, particularly high-severity fires: https://www.sciencedirect.com/…/abs/pii/S0378112719314744 .
Wildfires ARE a natural and essential part of ecosystems, helping to clear decay in forests and grasslands and return vital nutrients to the soils. But the scale and heat of these fires is unprecedented. It is clear from the research that warming-driven fuel drying is the link between increased wildfire activity and anthropogenic climate change.
“There is now an extremely high level of scientific confidence that human activities are the only plausible explanation for the observed ∼1.2°C rise in global mean temperature, and a human fingerprint has likewise been found in numerous other changes in climate.” – Swain et al., 2020
It will take a global effort to reduce our emissions and lower our temperature so that we can mitigate at least some of the coming disasters. What kind of new normal do we want? There are many solutions in play already (as mentioned in previous Science Wednesdays), but the point of this post is to inform on the science behind these fires and to encourage American voters to make their voices heard on November 3rd – to elect a new administration that will treat climate change as the threat it is. The “profit at all costs” model that corporations have adopted must end!