[MCN] Fires are climbing higher upslope, forests are losing trees, and who will most need to slash combustion of fossil fuels

[Lance Olsen]

News from the Washington Office, USDA Forest Service

Ain’t No Mountain High Enough: Why fires are climbing higher than ever before due to increased western aridity

Date: April 28, 2022

As the west has become more arid the occurrence and size of wildfires has increased—especially in high elevation forests.
Featured Publication

Warming enabled upslope advance in western US forest fires <https://www.fs.usda.gov/rmrs/publications/warming-enabled-upslope-advance-western-us-forest-fires>
Alizadeha, Mohammad Reza ; Abatzoglou, John T. ; Luce, Charles H. ; Adamowski, Jan F. ; Farid, Arvin ; Sadegh, Mojtaba , 2021


In areas like in high elevation western, mountainous regions with an abundance of moisture, snowpack, and cooler temperatures, fire has historically been less common. This study portrays a changing paradigm in fire’s ability to spread rapidly in high-elevation environments such as in the Sierra Nevada, the Pacific Northwest, and the Northern Rockies. This study documents a startling upslope trend for the fires of the United States—burning up territories that historically have been too wet, snowy, or high to burn—due to an increase in forest aridity.

While historical fire exclusion policies have had a strong effect on lower elevation forests, where fire was once a frequent visitor, past fire suppression has had less ecological effect on these high elevation forests where fire was rare and localized when it occurred. The reduced precipitation frequency and warming associated with climate change are effectively changing the fire regime of higher elevation forests. High elevation forests comprise species and fuels where crown fires can readily spread, and the shift in climate suggests that fuel treatments here could be as appropriate as in forests where management intervention in fire has led to fuel accumulations, particularly in proximity to inhabited areas.


The study observes changes in upslope advance in high-elevation forest fires, how climate aridity—and our warming planet—is correlated with these fires, and how biodiversity loss and vegetation conversion factor into these changing conditions. These changing conditions have significant implications for carbon storage, snowpack, and the western United States’ water quantity and quality.


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American Geophysical Union Advances 06 July 2022 
https://doi.org/10.1029/2021AV000654 <https://doi.org/10.1029/2021AV000654>

Losses of Tree Cover in California Driven by Increasing Fire Disturbance and Climate Stress
Jonathan A. Wang <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Wang%2C+Jonathan+A>,James T. Randerson <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Randerson%2C+James+T>,Michael L. Goulden <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Goulden%2C+Michael+L>,Clarke A. Knight <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Knight%2C+Clarke+A>,John J. Battles <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Battles%2C+John+J>


PDF <https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2021AV000654>


Abstract
Forests provide natural climate solutions for sequestering carbon and mitigating climate change, yet are increasingly threatened by increasing temperature and disturbance. Understanding these threats requires accurate information on vegetation dynamics and their drivers, which is currently lacking in many regions experiencing rapid climate change such as California. To address this, we combined remote sensing observations with geospatial databases to develop annual maps of vegetation cover (tree, shrub, and herbaceous) and disturbance type (fire, harvest, and forest die-off) in California at 30 m resolution from 1985 to 2021. Considering both changes in cover fraction and areal extent, California lost 4,566 km2 of its tree cover area (6.7% relative to initial cover) since 1985. Substantial gains in tree cover area during the 1990s were more than offset by fire-driven declines since 2000, resulting in greater shrub and herbaceous cover area. Tree cover loss occurred in all ecoregions but was most severe in the southern mountains, where losses from wildfire were not compensated by regrowth in undisturbed areas. Fires and tree cover area loss generally occurred where summer temperatures were greater than 17.5°C, whereas net tree cover gain often occurred in cooler areas, suggesting that ongoing climate warming is threatening forests in many areas. California's vegetation is undergoing rapid transformation, with disturbance rates and climate change posing substantial potential risks to the integrity of California's terrestrial carbon sink.

Key Points
We mapped annual disturbance and vegetation change in California from 1985 to 2021 using time series remote sensing and geospatial data
Tree cover area declined by 6.7% during the 37-year study period, primarily from increases in wildfire
Higher levels of tree cover loss in warmer and drier areas provide evidence that climate change threatens California's forests
Plain Language Summary
Trees provide nature-based solutions to slow climate change. However, increasing fires and drought threaten the integrity of forests in many parts of the world. These threats are especially important in areas experiencing rapid climate change, such as in California, yet it remains challenging to measure their impact because of a lack of digital vegetation maps at high spatial resolution that can accurately measure changes over a period of decades. In this study, we compiled satellite data and archival records with machine learning to map vegetation type (tree, shrub, and grass) and disturbance agent (fire, harvest, and drought) in California from 1985 to 2021. Over these 37 years, California lost 4,566 km2 of its tree cover area, equal to 6.7% of its initial tree cover in 1985. Tree cover area initially increased in the 1990s, but rapidly declined after 2000 from larger and more frequent wildfires, resulting in an expansion of shrub and grass cover area. Fires and tree cover loss generally occurred in warmer areas. Considering ongoing climate warming and disturbance trends, California's forest resources are likely to continue to decline, limiting the carbon sequestration potential of the state's natural and working lands.

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“Make no mistake about it: This is a race. As a recent IPCC press release <https://www.ipcc.ch/2022/04/04/ipcc-ar6-wgiii-pressrelease/> notes, to limit global warming to around 1.5º C, greenhouse gas emissions would have to peak “before 2025 at the latest, and be reduced by 43% by 2030.” 

Although carbon removal technology and trees will play a part, neither will get humanity remotely close in time. We’re logically left with one primary path: cutting the demand for fossil fuels.

“The hard truth about this path … is that it will require personal sacrifices, especially from the world’s wealthiest people. 

On average, the top 1% of global earners – people who earn $130,000 a year or more <https://wir2022.wid.world/chapter-1/> – cause 110 metric tonnes of carbon emissions each year per person. For perspective, that’s about 2,200 times the carbon burden of a typical citizen of Burundi.

“The world’s 1-percenters out-polluted <https://www.theguardian.com/environment/2020/sep/21/worlds-richest-1-cause-double-co2-emissions-of-poorest-50-says-oxfam> the poorest half of humanity twice over between 1990 and 2015, and recent estimates suggest they are collectively responsible for more than 11 times the annual greenhouse gas emissions attributed to notorious climate villain ExxonMobil <https://www.washingtonpost.com/business/2022/01/18/exxon-greenhouse-gas-net-zero/>. Meanwhile, the top 10% – which includes earners who make $39,100 a year, a middle class income for individuals in Global North countries like the US – produce nearly half of all carbon harms. No arithmetically coherent plan to cut carbon emissions can ignore this reality.”

https://science.thewire.in/environment/technofixes-elites-responsibility-climate-crisis/ <https://science.thewire.in/environment/technofixes-elites-responsibility-climate-crisis/>

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“… the serious meaning in a concept lies in the difference it will make to someone if it is true.”

William James (1842 –1910)
Pragmatism. Meridian Books, 1955

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Going 100% renewable power means a lot of dirty mining

EXCERPT 

Payal Sampat, the mining director at Earthworks, said recycling and technological innovation could go a long way toward reducing the demand for rare metals, but cautioned that still more needs to be done. “We’re not going to tech fix our way out of this,” she said. “It’s going to require more meaningful policy changes that fundamentally reduce the overall demand.”

<<https://grist.org/article/report-going-100-renewable-power-means-a-lot-of-dirty-mining/>>

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