James T Randerson
Dados Biográficos
| ID | 6231085 |
|---|---|
| NOME | James T Randerson |
| PRENOMES | James T |
| SOBRENOME | Randerson |
| ASSINATURA | RANDERSON J T |
| AFILIAÇÕES | University of California, Irvine |
| ORCID | 0000-0001-6559-7387 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 25 |
| TOTAL DE CITAÇÕES | 0 |
| TOTAL COMO AUTOR | 25 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1993 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2024 |
| ÍNDICE H | 0 |
Remote sensing for wildfire monitoring
Remote sensing plays a central role in monitoring wildfires throughout their life cycle, including assessing pre-fire fuel conditions, characterizing active fire locations and emissions, and evaluating post-fire effects on vegetation, air quality, and climate. This primer examines current remote sensing products used in wildfire research, focusing on their application in deriving burned area and emissions data and tracking the dynamic spread of i…
Rising forest exposure and fire severity from climate warming amplify tree cover losses from wildfire in California
Warmer temperatures and severe drought are driving increases in wildfire activity in the western United States, threatening forest ecosystems. However, identifying the influence of fire severity on tree cover loss (TCL) is challenging using commonly used categorical metrics. In this study, we quantify regional trends in wildfire-driven TCL as the product of annual burned area, average forest exposure (pre-fire tree cover), and average fire severi…
Evidence for multi-decadal fuel buildup in a large California wildfire from smoke radiocarbon measurements
In recent decades, there has been a significant increase in annual area burned in California’s Sierra Nevada mountains. This rise in fire activity has prompted the need to understand how historical forest management practices affect fuel composition and emissions. Here we examined the total carbon (TC) concentration and radiocarbon abundance (Δ 14 C) of particulate matter (PM) emitted by the KNP Complex Fire, which occurred during California’s 20…
Future increases in lightning ignition efficiency and wildfire occurrence expected from drier fuels in boreal forest ecosystems of western North America
Lightning-induced fire is the primary disturbance agent in boreal forests. Recent large fire years have been linked to anomalously high numbers of lightning-caused fire starts, yet the mechanisms regulating the probability of lightning ignition remain uncertain and limit our ability to project future changes. Here, we investigated the influence of lightning properties, landscape characteristics, and fire weather on lightning ignition efficiency—t…
Wildfire exacerbates high-latitude soil carbon losses from climate warming
Arctic and boreal permafrost soil organic carbon (SOC) decomposition has been slower than carbon inputs from plant growth since the last glaciation. Anthropogenic climate warming has threatened this historical trend by accelerating SOC decomposition and altering wildfire regimes. We accurately modeled observed plant biomass and carbon emissions from wildfires in Alaskan ecosystems under current climate conditions. In projections to 2300 under the…
Climate-driven risks to the climate mitigation potential of forests
Risks to mitigation potential of forests Much recent attention has focused on the potential of trees and forests to mitigate ongoing climate change by acting as sinks for carbon. Anderegg et al. review the growing evidence that forests' climate mitigation potential is increasingly at risk from a range of adversities that limit forest growth and health. These include physical factors such as drought and fire and biotic factors, including the depre…
Recent California tree mortality portends future increase in drought-driven forest die-off
Vegetation tolerance to drought depends on an array of site-specific environmental and plant physiological factors. This tolerance is poorly understood for many forest types despite its importance for predicting and managing vegetation stress. We analyzed the relationships between precipitation variability and forest die-off in California’s Sierra Nevada and introduce a new measure of drought tolerance that emphasizes plant access to subsurface m…
Harnessing cross-border resources to confront climate change
A human-driven decline in global burned area
Burn less, baby, burn less Humans have, and always have had, a major impact on wildfire activity, which is expected to increase in our warming world. Andela et al. use satellite data to show that, unexpectedly, global burned area declined by ∼25% over the past 18 years, despite the influence of climate. The decrease has been largest in savannas and grasslands because of agricultural expansion and intensification. The decline of burned area has co…
Global fire emissions estimates during 1997–2016
Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify g…
Are the impacts of land use on warming underestimated in climate policy
While carbon dioxide emissions from energy use must be the primary target of climate change mitigation efforts, land use and land cover change (LULCC) also represent an important source of climate forcing. In this study we compute time series of global surface temperature change separately for LULCC and non-LULCC sources (primarily fossil fuel burning), and show that because of the extra warming associated with the co-emission of methane and nitr…
Fire severity influences the response of soil microbes to a boreal forest fire
Wildfire activity is projected to increase in boreal forests as a result of climate warming. The consequences of increased wildfire activity for soil carbon (C) storage in boreal forests may depend on the sensitivity of soil microbes to fire severity, but microbial responses to boreal forest fire severity are not well known. Here, we combine remote sensing of fire severity and field sampling to characterize the response of soil microbial biomass …
How much global burned area can be forecast on seasonal time scales using sea surface temperatures
Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual b…
Identification of two distinct fire regimes in Southern California
The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California's wildfires can be partitioned by meteorology: fires typically occur eit…
Rate and velocity of climate change caused by cumulative carbon emissions
International climate mitigation efforts are focused on limiting increase in global mean temperature, which has been shown to be proportional to cumulative CO _2 emissions. However, the ability of natural and human systems to successfully adapt to climatic changes depends on both the magnitude and rate of change, the latter of which will depend on how quickly a given level of cumulative emissions occurs. We show that cumulative CO _2 emissions of…
A few extreme events dominate global interannual variability in gross primary production
A few extreme events dominate global interannual variability in gross primary production, Jakob Zscheischler, Miguel D Mahecha, Jannis von Buttlar, Stefan Harmeling, Martin Jung, Anja Rammig, James T Randerson, Bernhard Schölkopf, Sonia I Seneviratne, Enrico Tomelleri, Sönke Zaehle, Markus Reichstein
Analysis of daily, monthly, and annual burned area using the fourth‐generation global fire emissions database (GFED4)
We describe the fourth generation of the Global Fire Emissions Database (GFED4) burned area data set, which provides global monthly burned area at 0.25° spatial resolution from mid‐1995 through the present and daily burned area for the time series extending back to August 2000. We produced the full data set by combining 500 m MODIS burned area maps with active fire data from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scan…
Estimated Global Mortality Attributable to Smoke from Landscape Fires
Background: Forest, grass, and peat fires release approximately 2 petagrams of carbon into the atmosphere each year, influencing weather, climate, and air quality. Objective: We estimated the annual global mortality attributable to landscape fire smoke (LFS). Methods: Daily and annual exposure to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) from fire emissions was estimated globally for 1997 through 2006 by combining outputs from a…
Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009)
New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates. However, significant gaps remain in our understanding of the contribution of deforestation, savanna, forest, agricultural waste, and peat fires to total global fire emissions. Here we used a revised version of the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical mod…
Climate control of terrestrial carbon exchange across biomes and continents
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems \nis critical to predict future levels of atmospheric carbon dioxide because of the potential \naccelerating effects of positive climate–carbon cycle feedbacks. However, directly observed \nrelationships between climate and terrestrial CO2 exchange with the atmosphere across biomes \nand continents are lacking. Here we present data describing the relatio…
Trends in the sources and sinks of carbon dioxide
CO2 emissions from forest loss
Protecting climate with forests
Policies for climate mitigation on land rarely acknowledge biophysical factors, such as reflectivity, evaporation, and surface roughness. Yet such factors can alter temperatures much more than carbon sequestration does, and often in a conflicting way. We outline a framework for examining biophysical factors in mitigation policies and provide some best-practice recommendations based on that framework. Tropical projects—avoided deforestation, fores…
Primary Production of the Biosphere
Integrating conceptually similar models of the growth of marine and terrestrial primary producers yielded an estimated global net primary production (NPP) of 104.9 petagrams of carbon per year, with roughly equal contributions from land and oceans. Approaches based on satellite indices of absorbed solar radiation indicate marked heterogeneity in NPP for both land and oceans, reflecting the influence of physical and ecological processes. The spati…
Terrestrial ecosystem production
This paper presents a modeling approach aimed at seasonal resolution of global climatic and edaphic controls on patterns of terrestrial ecosystem production and soil microbial respiration. We use satellite imagery (Advanced Very High Resolution Radiometer and International Satellite Cloud Climatology Project solar radiation), along with historical climate (monthly temperature and precipitation) and soil attributes (texture, C and N contents) from…
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Terrestrial ecosystem production
This paper presents a modeling approach aimed at seasonal resolution of global climatic and edaphic controls on patterns of terrestrial ecosystem production and soil microbial respiration. We use satellite imagery (Advanced Very High Resolution Radiometer and International Satellite Cloud Climatology Project solar radiation), along with historical climate (monthly temperature and precipitation) and soil attributes (texture, C and N contents) from…
Primary Production of the Biosphere
Integrating conceptually similar models of the growth of marine and terrestrial primary producers yielded an estimated global net primary production (NPP) of 104.9 petagrams of carbon per year, with roughly equal contributions from land and oceans. Approaches based on satellite indices of absorbed solar radiation indicate marked heterogeneity in NPP for both land and oceans, reflecting the influence of physical and ecological processes. The spati…
Protecting climate with forests
Policies for climate mitigation on land rarely acknowledge biophysical factors, such as reflectivity, evaporation, and surface roughness. Yet such factors can alter temperatures much more than carbon sequestration does, and often in a conflicting way. We outline a framework for examining biophysical factors in mitigation policies and provide some best-practice recommendations based on that framework. Tropical projects—avoided deforestation, fores…
Trends in the sources and sinks of carbon dioxide
CO2 emissions from forest loss
Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009)
New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates. However, significant gaps remain in our understanding of the contribution of deforestation, savanna, forest, agricultural waste, and peat fires to total global fire emissions. Here we used a revised version of the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical mod…
Climate control of terrestrial carbon exchange across biomes and continents
Understanding the relationships between climate and carbon exchange by terrestrial ecosystems \nis critical to predict future levels of atmospheric carbon dioxide because of the potential \naccelerating effects of positive climate–carbon cycle feedbacks. However, directly observed \nrelationships between climate and terrestrial CO2 exchange with the atmosphere across biomes \nand continents are lacking. Here we present data describing the relatio…
Estimated Global Mortality Attributable to Smoke from Landscape Fires
Background: Forest, grass, and peat fires release approximately 2 petagrams of carbon into the atmosphere each year, influencing weather, climate, and air quality. Objective: We estimated the annual global mortality attributable to landscape fire smoke (LFS). Methods: Daily and annual exposure to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) from fire emissions was estimated globally for 1997 through 2006 by combining outputs from a…
Analysis of daily, monthly, and annual burned area using the fourth‐generation global fire emissions database (GFED4)
We describe the fourth generation of the Global Fire Emissions Database (GFED4) burned area data set, which provides global monthly burned area at 0.25° spatial resolution from mid‐1995 through the present and daily burned area for the time series extending back to August 2000. We produced the full data set by combining 500 m MODIS burned area maps with active fire data from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scan…
A few extreme events dominate global interannual variability in gross primary production
A few extreme events dominate global interannual variability in gross primary production, Jakob Zscheischler, Miguel D Mahecha, Jannis von Buttlar, Stefan Harmeling, Martin Jung, Anja Rammig, James T Randerson, Bernhard Schölkopf, Sonia I Seneviratne, Enrico Tomelleri, Sönke Zaehle, Markus Reichstein
Identification of two distinct fire regimes in Southern California
The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California's wildfires can be partitioned by meteorology: fires typically occur eit…
Rate and velocity of climate change caused by cumulative carbon emissions
International climate mitigation efforts are focused on limiting increase in global mean temperature, which has been shown to be proportional to cumulative CO _2 emissions. However, the ability of natural and human systems to successfully adapt to climatic changes depends on both the magnitude and rate of change, the latter of which will depend on how quickly a given level of cumulative emissions occurs. We show that cumulative CO _2 emissions of…
Fire severity influences the response of soil microbes to a boreal forest fire
Wildfire activity is projected to increase in boreal forests as a result of climate warming. The consequences of increased wildfire activity for soil carbon (C) storage in boreal forests may depend on the sensitivity of soil microbes to fire severity, but microbial responses to boreal forest fire severity are not well known. Here, we combine remote sensing of fire severity and field sampling to characterize the response of soil microbial biomass …
How much global burned area can be forecast on seasonal time scales using sea surface temperatures
Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual b…
A human-driven decline in global burned area
Burn less, baby, burn less Humans have, and always have had, a major impact on wildfire activity, which is expected to increase in our warming world. Andela et al. use satellite data to show that, unexpectedly, global burned area declined by ∼25% over the past 18 years, despite the influence of climate. The decrease has been largest in savannas and grasslands because of agricultural expansion and intensification. The decline of burned area has co…
Global fire emissions estimates during 1997–2016
Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify g…
Are the impacts of land use on warming underestimated in climate policy
While carbon dioxide emissions from energy use must be the primary target of climate change mitigation efforts, land use and land cover change (LULCC) also represent an important source of climate forcing. In this study we compute time series of global surface temperature change separately for LULCC and non-LULCC sources (primarily fossil fuel burning), and show that because of the extra warming associated with the co-emission of methane and nitr…
Harnessing cross-border resources to confront climate change
Climate-driven risks to the climate mitigation potential of forests
Risks to mitigation potential of forests Much recent attention has focused on the potential of trees and forests to mitigate ongoing climate change by acting as sinks for carbon. Anderegg et al. review the growing evidence that forests' climate mitigation potential is increasingly at risk from a range of adversities that limit forest growth and health. These include physical factors such as drought and fire and biotic factors, including the depre…
Recent California tree mortality portends future increase in drought-driven forest die-off
Vegetation tolerance to drought depends on an array of site-specific environmental and plant physiological factors. This tolerance is poorly understood for many forest types despite its importance for predicting and managing vegetation stress. We analyzed the relationships between precipitation variability and forest die-off in California’s Sierra Nevada and introduce a new measure of drought tolerance that emphasizes plant access to subsurface m…
Future increases in lightning ignition efficiency and wildfire occurrence expected from drier fuels in boreal forest ecosystems of western North America
Lightning-induced fire is the primary disturbance agent in boreal forests. Recent large fire years have been linked to anomalously high numbers of lightning-caused fire starts, yet the mechanisms regulating the probability of lightning ignition remain uncertain and limit our ability to project future changes. Here, we investigated the influence of lightning properties, landscape characteristics, and fire weather on lightning ignition efficiency—t…
Wildfire exacerbates high-latitude soil carbon losses from climate warming
Arctic and boreal permafrost soil organic carbon (SOC) decomposition has been slower than carbon inputs from plant growth since the last glaciation. Anthropogenic climate warming has threatened this historical trend by accelerating SOC decomposition and altering wildfire regimes. We accurately modeled observed plant biomass and carbon emissions from wildfires in Alaskan ecosystems under current climate conditions. In projections to 2300 under the…
Evidence for multi-decadal fuel buildup in a large California wildfire from smoke radiocarbon measurements
In recent decades, there has been a significant increase in annual area burned in California’s Sierra Nevada mountains. This rise in fire activity has prompted the need to understand how historical forest management practices affect fuel composition and emissions. Here we examined the total carbon (TC) concentration and radiocarbon abundance (Δ 14 C) of particulate matter (PM) emitted by the KNP Complex Fire, which occurred during California’s 20…
Remote sensing for wildfire monitoring
Remote sensing plays a central role in monitoring wildfires throughout their life cycle, including assessing pre-fire fuel conditions, characterizing active fire locations and emissions, and evaluating post-fire effects on vegetation, air quality, and climate. This primer examines current remote sensing products used in wildfire research, focusing on their application in deriving burned area and emissions data and tracking the dynamic spread of i…
Rising forest exposure and fire severity from climate warming amplify tree cover losses from wildfire in California
Warmer temperatures and severe drought are driving increases in wildfire activity in the western United States, threatening forest ecosystems. However, identifying the influence of fire severity on tree cover loss (TCL) is challenging using commonly used categorical metrics. In this study, we quantify regional trends in wildfire-driven TCL as the product of annual burned area, average forest exposure (pre-fire tree cover), and average fire severi…
Environmental Science (24 obras) · Fire effects on ecosystems (16 obras) · Climate change (15 obras) · Atmospheric and Environmental Gas Dynamics (14 obras) · Atmospheric sciences (14 obras) · Geography (14 obras) · Ecology (12 obras) · Climatology (11 obras) · Meteorology (11 obras) · Ecosystem (10 obras)