United States Energy Policy Simulator Update 3.3.1

Today, Energy Innovation updated the United States Energy Policy Simulator (EPS), our open-source, peer-reviewed, and nonpartisan model that estimates the environmental, economic, and health impacts of hundreds of climate and energy policies.

Version 3.3.1 adds several new features to the previously released 3.3 model platform. For example, the model now accounts for vehicle insurance, parking, licensing and registration costs, and tracks changes in the amount of money paid for passenger transport fares. It also includes several new graphs showing total energy use by sector and greater flexibility in settings for power plant and fuel subsidies and taxes.

The abatement cost curves above demonstrate the improved accuracy of the transportation mode shifting costs in this example policy package (left-most box).

The latest launch also includes several data improvements such as updating the U.S. business-as-usual (BAU) trajectory to reflect the American Innovation and Manufacturing Act, which will phase down the production and consumption of hydrofluorocarbons, and to update BAU carbon capture and sequestration deployment. The new features are available online now, and a full list of updates is available on our Version History page. If you would like to introduce any friends or colleagues to the EPS, the EPS Video Series provides the best possible introduction to the tool. They can also jump right in and begin playing with the simulator in its web interface.

 

Energy Policy Solutions Updates

Sign up to hear about new updates to the Energy Policy Simulator model, new regions covered by the tool, and new insights from our research.

* indicates required

The post United States Energy Policy Simulator Update 3.3.1 appeared first on Energy Innovation: Policy and Technology.

U.S. Energy Policy Simulator 3.3.1 adds several new features covering the transportation and power sectors, and includes data improvements like an updated business-as-usual trajectory to reflect the American Innovation and Manufacturing Act as well as carbon capture and sequestration deployment. 
The post United States Energy Policy Simulator Update 3.3.1 appeared first on Energy Innovation: Policy and Technology.

Dusting For “Fingerprints” On Our Climate: Innovations In The Attribution Of Extreme Events

Energy Innovation partners with the independent nonprofit Aspen Global Change Institute (AGCI) to provide climate and energy research updates. The research synopsis below comes from AGCI Executive Director James Arnott, and a full list of AGCI’s quarterly research updates covering recent climate change research on clean energy pathways is available online at https://www.agci.org/solutions/quarterly-research-reviews

This blog is dedicated to the memory of Geert Jan van Oldenborgh, a pioneer in the attribution of extreme climate events. Van Oldenborgh passed away during the writing of this post. More about this scientist and the impact of his life work is available here.

The lived experience of much our planet’s life now reflects what scientists have long expected: extreme climate and weather events are increasing as our planet warms. In many cases, the most intense heatwaves, droughts, fires, and floods have become not only more frequent but also more severe. For instance, the latest Intergovernmental Panel on Climate Change (IPCC) assessment of climate science finds that, globally, extreme heat events that used to occur once in every 50 years now happen nearly five times as often and are more than 1-degree Celsius (1.8 degrees Fahrenheit) hotter (IPCC, 2021).

These global trends raise local questions. Did global warming cause last week’s heat wave (or wildfire or flood or hurricane) in my hometown? Scientists treat this inquiry a bit like detective work, attempting to find a human “fingerprint” in climate and weather phenomena. Extreme events, by definition, are rare. This makes identifying fingerprints for just a single occurrence more difficult than attributing global trends in extremes to human-driven climate change (as the IPCC does with increasing confidence).

However, scientists are finding ways to produce so-called “attribution” studies. Analytical advances, along with communicating findings better, mean attribution studies are now more relevant for impacted communities, policymakers, and the media in the wake of a particular extreme event.

For example, an attribution study by Phillip et al. on the Western North America (WNA) heatwave that crippled the Pacific Northwest in the summer of 2021 produced striking results. The analysis compared observations of the heatwave to the simulated climate of the region without elevated levels of greenhouse gases (GHGs). The authors found events like the WNA heatwave would be 150 times less likely to occur in a natural climate.

Even in our current GHG-polluted climate, the event would be expected to occur only once every 1,000 years. Furthermore, the same analysis calculated that the probability of future extreme heatwaves would increase to one every five to ten years in a world that experiences 2°C of climate warming—a future we are rapidly approaching, and which national commitments made at the recent COP26 in Glasgow fall short of preventing.

Perhaps as remarkable as the findings of the WNA heatwave study is how, and how quickly, scientists were able to produce the results. The study was conducted and disseminated within nine days of the event (light speed in the academic time-space continuum). Applying the peer-reviewed methods from a team of scientists called World Weather Attribution (WWA) made this rapid response possible. Examples of other studies this group has released since 2017 are shown in the table below, produced in the wake of natural disasters like Hurricane Harvey, the Australian wildfires, and the extreme floods in Europe and Bangladesh.

Event (link to study)
Probability of occurrence in current climate
Probability of occurrence in 2º world
Attribution Summary

2021 Western North American Heatwave
About 1 in 1,000 years
1 in every 5 to 10 years
Event was virtually impossible without human-driven climate change (150 times less likely to occur in natural climate).

2017 Hurricane Harvey (rainfall)
1 in 9,000 years
Not available
Human-driven climate change made precipitation 15% more intense, increased probability of event 1.5-5x.

2020 Australian Brushfire (fire weather)
1 in 33 years
4x more likely (at least)
Part of increase in fire weather index attributed to climate change, though extent may be underrepresented in models.

2017 Bangladesh Floods
Not available.
1 – 2x more likely
Cannot say with confidence that event was caused by human-driven climate change.

2021 Western European Floods
1 in 400 years
1.2 – 1.4x more likely
Climate change influenced rainfall but flooding driven by numerous factors. Small area and extensive storm damage to monitoring equipment limits conclusiveness.

WWA combines peer-reviewed methods with considerations for how best to convey and disseminate the outcomes of each study. A recent article in Climatic Change by Geert Jan van Oldenborgh and colleagues outlines this approach (2021). While Van Oldenborgh (who passed away during the writing of this piece) and many of his co-authors spent much of their careers advancing the physical science of attribution, their work’s most lasting impact may be how they constructed a workflow that could rapidly relay attribution science’s findings to larger audiences.

The attribution process begins with several judgment calls. Extreme events are almost always happening somewhere on the planet, so researchers must first decide which extreme events to study, given limited technical resources. They must also define the event in terms of climate variables, timing, and location. Any one of these choices can influence the outcome of an attribution study and its implications. For instance, van Oldenborgh et al. (2017) found that while the probability of Hurricane Harvey precipitation happening in Houston was one in more than 9,000 years, the interval for such a storm recurring anywhere in the Gulf was only one in 800 years.

Once researchers decide to study a specific event, the next phase is collecting and analyzing observations from the affected area. Some regions of the world have better monitoring coverage than others. Importantly, reduced coverage, quality, or access to data can increase the level of uncertainty about the extent to which a particular event exceeded historical levels. This is especially true in countries with low- and middle-income countries, where technical and financial resources to establish monitoring networks have disproportionately lagged.

Similarly, some events may take place at such a small scale that statistical confidence in the extremity of the event decreases. The physical impacts of some events can also directly impair the monitoring equipment during the event itself, as was the case in the 2021 Western Europe floods, which destroyed long-term flood monitoring stations and prevented a full accounting of their magnitude.

In parallel to evaluating observational quality, the analysis phase of attribution relies on selecting climate models skillful at representing the historical distribution for the event type and region. Using models that meet a minimum performance standard helps researchers ensure they use the best possible simulated climate to compare observations. By comparing the observed world (with human emissions) and the simulated counterfactual world (without human emissions), researchers can calculate the likelihood an event is attributable to human-caused climate change. Observed events that significantly exceed ranges of variability from the counterfactual model reveal clearer fingerprints of human influence.

In characterizing conclusions, the attribution process that van Oldenborgh et al. outline attempts to provide several key results, including 1) the probability of the event occurring in the current climate, 2) the probability of the event occurring in a future climate with elevated warming, and 3) a synopsis appraisal of how (and how confidently) one can attribute the event to human-driven climate change. Often these results come with caveats, such as when modeling or observational data is limited or when climate impacts result from compounding factors (e.g., fires are often the result of heat, wind, precipitation, and various forms of ignition). Ultimately, any attribution result is probabilistic rather than unequivocal, owing to the statistical nature of how we understand the global climate.

Since the human mind gravitates toward events in the here and now, rapid response attribution studies have the potential to help people draw more tangible connections between global climate change and their own well-being. The World Weather Attribution’s approach is exciting because it showcases how the scientific community can apply new computing tools, as well as new orientations toward public service, to make their research more actionable. Ultimately, though, as the IPCC shows us with increasing confidence, every fraction of degree of warming avoided will limit the further intensification of extremes.

Featured research
IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. In Press.
Philip, S.Y., Kew, S.F., Oldenborgh, G.J. Van, Yang, W., Vecchi, G.A., Anslow, F.S., Li, S., Seneviratne, S.I., Luu, L.N., Arrighi, J., Singh, R., Aalst, V., Hauser, M., Schumacher, D.L., Marghidan, C.P., Ebi, K.L., Vautard, R., Tradowsky, J., Coumou, D., Lehner, F., Rodell, C., Stull, R., Howard, R., Gillett, N., Otto, F.E.L., 2021. Rapid attribution analysis of the extraordinary heatwave on the Pacific Coast of the US and Canada June 2021 . 119–123.
van Oldenborgh, G.J., van der Wiel, K., Kew, S., Philip, S., Otto, F., Vautard, R., King, A., Lott, F., Arrighi, J., Singh, R., van Aalst, M., 2021. Pathways and pitfalls in extreme event attribution. Clim. Change 166, 1–27. https://doi.org/10.1007/s10584-021-03071-7
van Oldenborgh, G.J., van der Wiel, K., Sebastian, A., Singh, R., Arrighi, J., Otto, F., Haustein, K., Li, S., Vecchi, G., Cullen, H., 2017. Attribution of extreme rainfall from Hurricane Harvey, August 2017. Environ. Res. Lett. 12, 124009. https://doi.org/10.1088/1748-9326/aa9ef2

The post Dusting For “Fingerprints” On Our Climate: Innovations In The Attribution Of Extreme Events appeared first on Energy Innovation: Policy and Technology.

Extreme weather events are becoming more frequent and more severe as climate change accelerates. Advances in modeling now make it possible to more quickly and reliably determine to what extent global warming causes individual events, offering greater opportunities to educate the public about climate change impacts.
The post Dusting For “Fingerprints” On Our Climate: Innovations In The Attribution Of Extreme Events appeared first on Energy Innovation: Policy and Technology.

How “Agrivoltaics” Can Provide More Benefits Than Agriculture And Solar Photovoltaics Separately

Energy Innovation partners with the independent nonprofit Aspen Global Change Institute (AGCI) to provide climate and energy research updates, and a full list of AGCI’s quarterly research updates covering recent climate change research on clean energy pathways is available online at https://www.agci.org/solutions/quarterly-research-reviews

Solar photovoltaic (PV) technology is pivotal in the transition to a low-carbon energy system. Yet wide-scale deployment may be hindered due to fears about sustainability tradeoffs and pockets of social resistance. For instance, deployment of PV farms can compete with agriculture for the use of the same land for food production and may create local tensions about how land is used and allocated.

However, an emerging strategy known as agrivoltaics combines solar electricity generation with agricultural production in the same location. As shown in Figure 1, more and more research is evaluating agrivoltaics for its potential to enhance land-use efficiency, climate solutions, sustainable food, and local economies. Different agrivoltaic configurations—such as combining PV with croplands, pastures, or pollinator habitats—may contribute to achieving sustainable energy and food goals simultaneously, while possibly reducing local opposition to PV deployment. This article reviews a few recent studies that uncover what researchers are finding about the myriad potential benefits of agrivoltaics.

Figure 1. Number of relevant agrivoltaic academic papers published yearly. Source: Toledo et al., 2021.

Agrivoltaic systems are shown to increase crop production, among other benefits, in drylands

A study by Barron-Gafford and colleagues compared the food, energy, and water implications of an agrivoltaic system to a traditional agriculture system in Arizona. Across the plants examined (chiltepin pepper, jalapeño, and cherry tomato), fruit production doubled in the agrivoltaic system relative to the traditional environment. Due to the cooling effect of plant transpiration on the solar panels (Figure 2), there were also marginal improvements to electricity production. The agrivoltaic PV system generated 1 percent more electricity on an annual basis (3 percent increase during summer months) compared to a regular PV system in the same location. Additionally, carbon dioxide uptake and water use efficiency were also both higher (both by 65 percent) in the agrivoltaic system, which the authors suggest aided overall productivity by reducing plant stress due to heat and drought.

Figure 2. Illustration of changes in midday energy exchange with transitions from natural systems, solar PV arrays and a collocated agrivoltaic system. a,b, Assuming equal rates of incoming energy from the sun (broken yellow arrows), a transition from a vegetated ecosystem (a) to a solar PV installation (b) will significantly alter the energy flux dynamics of the area because of the removal of vegetation, and thus the latent heat fluxes (blue arrows). This leads to greater sensible heat fluxes (red and orange arrows), which yield higher localized temperatures. c, Reintroduction of vegetation, in this case agricultural plants, restores latent heat fluxes and should reduce sensible heat loss to the atmosphere. Energy re-radiation from PV panels (teal arrows) and energy transferred to electricity (green arrows) are also shown. Arrow size and abundance correspond to the magnitude of the effect. Source: Barron-Gafford et al., 2019.

Agrivoltaic systems can support economic development of rural communities in developing countries

A recent study conducted by Choi and collaborators sought to estimate the benefits of implementing agrivoltaics in rural communities in low- and middle-income countries. The authors selected Indonesia as a test case and applied a life cycle analysis approach to estimate the effects of different land-use scenarios on greenhouse gas emissions, income, and environmental co-benefits.

The model-based results showed that “small-scale agrivoltaic systems are economically viable in certain configurations and can potentially provide co-benefits including rural electrification, retrofitting diesel electricity generation, and providing electricity for local processing of agricultural products.” The authors also noted the barrier of high capital expenditures solar, which currently may be difficult to justify absent increases in subsidies for solar or reductions in subsidies for fossil fuels.

Pasture-based agricultural processes may also be improved through agrivoltaics

Relatively less research has explored how agrivoltaics could work in pasture settings. An April 2021 research article by Andrew and colleagues in Frontiers in Sustainable Food Systems conducted an experiment that monitored sheep grazing on both agrivoltaic and traditional pastures open over two years. Predictably, shady plots with solar panels generated less herbage than the sunnier, open pastures. However, lambs in both the traditional and agrivoltaic plots gained weight at nearly the same rate. The authors found reduced quantity in herbage due was made up for by higher quality forage in shady areas, possibly alongside reduced heat stress and more effective foraging behavior when sheep roamed among the PV panels. All told the comparable outcomes in lamb production between the two treatments indicate opportunities for improved land-use efficiency in an agrivoltaic pasture system.

A related study explored the opportunities of shifting conventional animal feeding operations and conventional PV farms to pasture-based arrangements that integrate PV. In Cleaner and Responsible Consumption, Pascaris and colleagues explored this potential using life cycle analysis on different scenarios of rabbit and electricity production (as shown in Figure 3). When comparing emissions from the energy utilized to mow grass in conventional PV farms and supply processed feed for conventional rabbit farms, the authors estimated substantial reductions in emissions by converting to an agrivoltaic configuration. In the agrigvoltaic scenario, rabbits fed on natural grass, eliminating the need for additional feedstock or mowing operations, resulting in sizable emissions reductions gains.

Figure 3. Comparison of greenhouse gas (GHG) emissions and fossil energy demand between an agrivoltaic integrated system, separate rabbit farming and PV production, and separate rabbit farming and conventional energy production. GHG emissions and fossil energy demand are broken down to show solar system, housing system (includes lighting, heating, and water), use stage (conventional rabbit feeding and vegetative maintenance of the PV array—estimated at two mows and six herbicide applications per year), and electricity. Source: Pascaris et al., 2021.

Agrivoltaic systems can restore pollinator habitat

Relative to PV with crops or PV with pasture, the most widely deployed form of dual-use PV in the United States to date is called “pollinator-friendly PV.” This type of agrivoltaic strategy installs solar arrays on top of pollinator habitat, which according to the National Renewable Energy Laboratory (NREL) is already utilized in more than 1 gigawatt of U.S. PV installations.  A field study by Graham and colleagues published earlier this year in Nature Scientific Reports compared the composition and behavior of foraging pollinators between fully and partially shaded plots under solar arrays and on full-sun (control) plots at the Eagle Point Solar Plant in southwestern Oregon (Figure 4). Although the fully shaded areas directly beneath the panels attracted far fewer pollinating insects, the researchers observed more types and greater numbers of insects in the partial-shade plots, relative to the full-sun plots, at certain times throughout the growing season. Although pollinators were observed to actually visit plants at comparable rates between each of the treatment areas, some plants in the partial shade plots bloomed later, which the authors suggested could benefit late-season pollinators.

Figure 4. Photo (c) shows a side view of the full shade (~5 percent full sun) and partial shade (~75 percent full sun) plots used in this study. Photo (d) shows the control full sun plots in yellow, partial shade in green, and full shade in turquoise. Source: Graham et al., 2021. Note that the solar array consists of monocrystalline solar panels, which typically have the highest efficiencies and power capacity. Other types of solar panels can allow for more sunlight to go through them, therefore increasing sunlight availability underneath them. A final note is that prior to solar development, this site was used for cattle grazing, which serves as an empirical example of the land-use tensions between agriculture and utility-scale solar PV.

Agrivoltaic systems may improve public support for solar PV development

In a May 2021 pre-print posted to SocArXiv (open archive of social science research not yet under peer-review), Pascaris and colleagues reported on a survey of nearly 200 respondents across in Lubbock County, TX and Houghton County, MI. Although most of these respondents already expressed favorable attitudes toward solar deployment (72 percent), a marginally higher percentage (81 percent) indicated they would be even more supportive of local solar installations if they were combined with agriculture production. Although the results signaled that agrivoltaic proposals could further reduce local opposition, they also tracked the considerations important to communities when deliberating over solar projects – namely, that proposed agrivoltaic projects need to take into account local concerns such as how the project would provide economic benefits to farmers, the fairness in how economic benefits are distributed, the details of the siting of any new installations, and the overall alignment with local interests.

Conclusion

What can we take away from these recent studies? At the very least, each showcases the ability for agrivoltaics to increase land-use efficiency without sacrificing much in the way of either energy or food production. Furthermore, many agrivoltaic configurations appear even to enhance both food and energy production while at the same time reducing the environmental impact from pursuing each activity as a standalone.

While this area of research is still advancing, findings from these particular studies can help to inform optimal designs and standards for emerging applications of agrivoltaics. To date, little support and guidance on best-practice implementation, let alone policy, exists to foster agrivoltaic deployment. Yet if current signals in research hold up, agrivoltaics may help low-carbon energy to become synergistic with, rather than competitive with, other sustainable development goals.

Featured Research
Toledo, C.; Scognamiglio, A. Agrivoltaic Systems Design and Assessment: A Critical Review, and a Descriptive Model towards a Sustainable Landscape Vision (Three-Dimensional Agrivoltaic Patterns). Sustainability 2021, 13, 6871. https://doi.org/10.3390/su13126871
Pascaris, A. S., Schelly, C., Rouleau, M., & Pearce, J. M. (2021, May 5). Do Agrivoltaics Improve Public Support for Solar Photovoltaic Development? Survey Says: Yes!. https://doi.org/10.31235/osf.io/efasx
Barron-Gafford, G.A., Pavao-Zuckerman, M.A., Minor, R.L. et al. Agrivoltaics provide mutual benefits across the food–energy–water nexus in drylands. Nat Sustain 2, 848–855 (2019). https://doi.org/10.1038/s41893-019-0364-5
Horowitz, Kelsey, Vignesh Ramasamy, Jordan Macknick and Robert Margolis. 2020. Capital Costs for Dual-Use Photovoltaic Installations: 2020 Benchmark for GroundMounted PV Systems with Pollinator-Friendly Vegetation, Grazing, and Crops. Golden, CO: National Renewable Energy Laboratory. NREL/TP-6A20-77811. https://www.nrel.gov/docs/fy21osti/77811.pdf.
Andrew AC, Higgins CW, Smallman MA, Graham M and Ates S (2021) Herbage Yield, Lamb Growth and Foraging Behavior in Agrivoltaic Production System. Front. Sustain. Food Syst. 5:659175. Doi: 10.3389/fsufs.2021.659175
Alexis S. Pascaris, Rob Handler, Chelsea Schelly, Joshua M. Pearce (2021) Life cycle assessment of pasture-based agrivoltaic systems: Emissions and energy use of integrated rabbit production. Cleaner and Responsible Consumption, Volume 3, 2021, 100030, ISSN 2666-7843, https://doi.org/10.1016/j.clrc.2021.100030.
Graham, M., Ates, S., Melathopoulos, A.P. et al. Partial shading by solar panels delays bloom, increases floral abundance during the late-season for pollinators in a dryland, agrivoltaic ecosystem. Sci Rep 11, 7452 (2021). https://doi.org/10.1038/s41598-021-86756-4

The post How “Agrivoltaics” Can Provide More Benefits Than Agriculture And Solar Photovoltaics Separately appeared first on Energy Innovation: Policy and Technology.

Solar power plays an essential role in the clean energy transition, but its land-use requirements put it in direct competition with agriculture. New research on agrivoltaics demonstrates the benefits of combining both solar and agricultural production including increased productivity, water conservation, and local economic development, while also bolstering public support for clean energy.
The post How “Agrivoltaics” Can Provide More Benefits Than Agriculture And Solar Photovoltaics Separately appeared first on Energy Innovation: Policy and Technology.

After The Megafires: What’s Left And What’s Next

Energy Innovation partners with the independent nonprofit Aspen Global Change Institute (AGCI) to provide climate and energy research updates. The research synopsis below comes from AGCI Program Director Emily Jack-Scott and a full list of AGCI’s quarterly research updates covering recent climate change research on clean energy pathways is available online at https://www.agci.org/solutions/quarterly-research-reviews

Something is clearly different about the wildfires roaring in the western United States. Over the last decade, we have increasingly used terms like “megafires” and “gigafires” (fires that burn more than a hundred thousand, and more than a million acres, respectively) to describe them. They’re staggering, not just in size, but also severity. Fire seasons are lasting longer, and lifelong firefighters are getting mentally and physically burned out.

Flames of the 2018 Lake Christine fire climb up “ladder fuels” into the crowns of dense forests atop Basalt Mountain in Colorado. This fire necessitated the evacuation of many residents of Basalt, CO, and the Aspen Global Change Institute office. Photo credit: Emily Jack-Scott.

We know fires have a long history in western montane ecosystems, but the fires of the last couple decades are a new beast. We’re seeing a perfect storm play out – the result of long-term fire suppression initiated by Euro-American colonists, climate change, and more people than ever building permanent dwellings in fire-prone forests (for more on wildfire attribution refer to our previous research review). We’re left with a new reality of increasingly frequent, more intense wildfires, greater loss of property and life, and a multitude of questions about what will be left when the megafires are out.

What kind of ecosystems will regenerate? How long will it take to see new growth? Will these continue to be landscapes humans and other animals can inhabit? For those of us living in the West – breathing thick smoke for weeks on end, watching neighbors and loved ones troop off for months to battle blazes – these questions are deeply personal and increasingly urgent.

The latest scientific research confirms that we must be prepared for a dramatically altered landscape in the coming decades. In 2020, Coop and colleagues published research illustrating how relatively small changes in fire behavior have widespread impacts, converting forests into non-forests over massive swaths of the West. As summarized by Coop, many researchers are forecasting fire-driven conversion of 30 to 50 percent of most western conifer-dominated forests into non-forested shrublands, grasslands or hardwood-dominated ecosystems before 2100 (Coop et al. 2020).

Figure 1. Top photo: View from atop Slate Peak in northeastern Washington, looking southwest, 1934, George Clisby photograph, National Archives, Seattle, Washington, USA. The 1934 panoramic view shows extensive evidence of prior wildfires, varied age classes of cold forest, and recently burned and recovering areas. In the same view nearly eight decades later (bottom photo, 2013, John Marshall Photography), note the complete absence of recent fire evidence, widespread ingrowth creating denser forests, loss of nonforest, and lack of forest successional heterogeneity. Source: Hessburg et al. 2021.

Historically, fire-adapted forests evolved to tolerate low- to moderate-severity fires. Because fires burned on regular intervals, forests were often more open, and understory plants were less likely to grow tall enough to serve as “ladder fuels” (serving as a ladder for fires on the ground story to climb up into the crowns of trees, escalating the fire intensity). Even if smaller younger trees perished in those fires, larger older trees could withstand the ground fires and provide a seed source for trees to regenerate amidst the grasses and shrubs that opportunistically sprout in the wake of fires.

But we’re seeing higher severity fires, in denser forests, over larger areas. As Hagmann and colleagues explore in depth in their 2021 paper, there is overwhelming evidence to confirm changing forest conditions and changing fire regimes. Fires now climb more easily up into the crowns of mature trees, and burn too hot for even thick-barked mature trees to withstand. And because our forests have lost their heterogeneity of ages and structures (see Figure 1), megafires are scorching more uniformly over broader swaths. So megafires are leaving behind tens, or even hundreds of thousands of acres scorched without enough seed trees to contribute to the usual succession of plant species that have historically regenerated after fires in the West.

Even when seed trees persist, soils can be so scorched that their life-giving nutrients actually volatilize into the atmosphere. Soil structure can be so altered that instead of absorbing water they actually repel it, rendering them far more prone to erosion. So even the most resilient of landscapes are left barren and dry after high severity fires. In these cases, it can take decades to rebuild even baseline conditions hospitable enough to support the natural succession of forests. And that’s assuming historical climatic conditions.

Climate change is creating hotter and drier conditions which further deter recovery. Seeds have a harder time germinating and growing to maturation, and fires are more frequent – sweeping through areas still in early recovery stages after the last severe burn.

These dynamics all culminate in what ecologists refer to as conversion – a transformation into a new ecological state, with new dominant species, usually filling different ecological functions. The conversion of a forest to a non-forest may happen as the result of a single large, high-severity fire, or it may happen as the result of post-fire conditions that make the burned area more likely to burn again before forest regeneration can occur (Figure 2).

Figure 2. Processes that may give rise to fire-driven forest conversion. (a) Conversion is initiated by processes that result in extensive areas of adult tree mortality (the solid arrows; red represents fire, and yellow represents climate). (b) Conversion is maintained by processes that impede regeneration of pre-fire tree species (dashed red and yellow arrows) and protract vegetation change temporally. (c) The duration of forest conversion may be further influenced by positive and negative fire–vegetation feedbacks (dashed purple arrows), which respectively promote or inhibit additional burning. Source: Coop et al. 2020.

When dense forests burn, they leave behind partially burned dead and dying trees for the next fire to re-burn in the same area. These secondary high-severity fires can actually burn hotter than the initial fire, killing off any seedlings or young trees and reinforcing conversion. This is especially true at the edges of forests, where trees are often already at the limits of tolerable growing conditions (Parks et al. 2019).

So what can be done? The scale of this challenge is massive, and outstrips current management techniques and budgets. But managers do still have the options to engage in strategic operations, especially in “high value” locations (such as in high-use recreation areas, timber stands, municipal watersheds, or near residential areas). It comes down to a choice between resisting, accepting, or directing conversion.

Coop and colleagues lay out a great framework to help inform that choice:

Use the modeling and mapping research available to assess the likelihood of fire-driven conversion in the area in question
Consider the ecological fallout of a disturbance in the area in the midst of a changing climate
Increase heterogeneity of forests at stand and landscape scales (through mechanical thinning, prescribed fires, allowing certain low- to moderate-intensity wildfires to burn, forestry operations, and strategic tree planting)
Incorporate social science into decision-making to aid managers in an increasingly difficult position to understand societal values and social acceptability of management choices, especially novel approaches that direct conversion

Hessburg and colleagues echoed many of these recommendations in a 2021 paper. They acknowledge the understandable societal resistance to large-scale management techniques – the result of broken trust as a result of extensive logging of old growth forests in the 1900s. But they make the case for intentional and proactive management of western forests in the form of prescribed fires, managed wildfires, and silvicultural treatments.

Mountain Pine Beetle-killed lodgepole pines are piled in preparation for winter pile-burning to reduce fuels at a high value recreation area on public lands near Helena, MT. Photo credit: Emily Jack-Scott.

They argue it is critical to cut through the politicization of forestry management approaches, in order for western forests to better adapt to climate change and high-severity wildfires. They advocate for application of best available science (including Indigenous and western knowledges) in designing intentional management strategies, even though there will be unavoidable uncertainty in that science. On this point, they lean into a discussion about not having the precautionary principle unnecessarily translate into inaction.

Under the precautionary principle, a decision-maker must demonstrate in the face of uncertainty that the most likely outcome is one of no harm. But given the inherent uncertainties at the convergence of changing climate and changing fire regimes, they caution against basing decisions about forest management solely on that principle. This can lead managers to assume a course of non-action, deferring to natural processes alone. Rather, they lay out a series of questions to inform decision-making under uncertainty:

“What are the uncertainties, trade-offs, and likely consequences to U.S., Canadian, and Mexican Indigenous and nonindigenous people, infrastructure, ecosystems, native species and habitats of
1) Restoring active fire regimes to dry, moist, and cold forest ecosystems,
2) Continued fire suppression in these same forest types,
3) Proposed proactive, reactive, and no-action management alternatives,
4) Post-fire forest regeneration under action and no-action alternatives, and
5) Post-fire harvest/non-harvest of the younger fire-killed trees to mimic reburns?”

Ultimately forest managers are entering a new era. The heat is on for managers to counteract the massive threats to forest resilience we’re watching unfold. They will need to find novel ways to replicate low- and moderate-fire disturbances (through selective logging, prescribed burns, and managed burns), promote forest structure heterogeneity, and protect old growth forests and drought-tolerant trees. It will look unconventional, and in reality may be experimental at times – but the alternative of nonaction renders many western forests at risk of conversion, and ultimately the loss of many of our forested habitats.

Featured research
Coop, J.D., Parks, S.A., Stevens-Rumann, C.S., Crausbay, S.D., Higuera, P.E., Hurteau, M.D., Tepley, A., Whitman, E., Assal, T., Collins, B.M. and Davis, K.T., 2020. Wildfire-driven forest conversion in western North American landscapes. BioScience, 70(8), pp.659-673.
Hagmann, R.K., Hessburg, P.F., Prichard, S.J., Povak, N.A., Brown, P.M., Fulé, P.Z., Keane, R.E., Knapp, E.E., Lydersen, J.M., Metlen, K.L. and Reilly, M.J., 2021. Evidence for widespread changes in the structure, composition, and fire regimes of western North American forests. Ecological applications, p.e02431.
Hessburg, P. F., S. J. Prichard, R. K. Hagmann, N. A. Povak, and F. K. Lake. 2021. Wildfire and climate change adaptation of western North American forests: a case for intentional management. Ecological Applications 00(00):e02432. 10.1002/eap.2432
Parks, S.A., Dobrowski, S.Z., Shaw, J.D. and Miller, C., 2019. Living on the edge: trailing edge forests at risk of fire‐facilitated conversion to non‐forest. Ecosphere, 10(3), p.e02651.

 

The post After The Megafires: What’s Left And What’s Next appeared first on Energy Innovation: Policy and Technology.

Research shows increasingly frequent, more intense wildfires in the Western U.S. will dramatically shift the landscape over the coming decades, resulting in the conversion of forests to shrublands, grasslands, or hardwood-dominated ecosystems before 2100, but strategies such as prescribed fires, managed wildfires, and silvicultural treatments could help protect forests.
The post After The Megafires: What’s Left And What’s Next appeared first on Energy Innovation: Policy and Technology.

How to “Woo” a Recruiter and Land Your Dream Job

Collaboratively administrate empowered markets via plug-and-play networks. Dynamically procrastinate B2C users after installed base benefits. Dramatically visualize customer directed convergence without revolutionary ROI.

Efficiently unleash cross-media information without cross-media value. Quickly maximize timely deliverables for real-time schemas. Dramatically maintain clicks-and-mortar solutions without functional solutions.

Completely synergize resource taxing relationships via premier niche markets. Professionally cultivate one-to-one customer service with robust ideas. Dynamically innovate resource-leveling customer service for state of the art customer service

Hirebucket

FREE
VIEW