Historical (1700–2012) global multi-model estimates of the fire emissions from the Fire Modeling Intercomparison Project (FireMIP)

Fire emissions are a critical component of carbon and nutrient cycles and strongly affect climate and air quality. Dynamic global vegetation models (DGVMs) with interactive fire modeling provide important estimates for long-term and large-scale changes in fire emissions. Here we present the first multi-model estimates of global gridded historical fire emissions for 1700–2012, including carbon and 33 species of trace gases and aerosols. The dataset is based on simulations of nine DGVMs with different state-of-the-art global fire models that participated in the Fire Modeling Intercomparison Project (FireMIP), using the same and standardized protocols and forcing data, and the most up-to-date fire emission factor table based on field and laboratory studies in various land cover types. We evaluate the simulations of present-day fire emissions by comparing them with satellite-based products. The evaluation results show that most DGVMs simulate present-day global fire emission totals within the range of satellite-based products. They can capture the high emissions over the tropical savannas and low emissions over the arid and sparsely vegetated regions, and the main features of seasonality. However, most models fail to simulate the interannual variability, partly due to a lack of modeling peat fires and tropical deforestation fires. Before the 1850s, all models show only a weak trend in global fire emissions, which is consistent with the multi-source merged historical reconstructions used as input data for CMIP6. On the other hand, the trends are quite different among DGVMs for the 20th century, with some models showing an increase and others a decrease in fire emissions, mainly as a result of the discrepancy in their simulated responses to human population density change and land use and land cover change (LULCC). Our study provides an important dataset for further development of regional and global multi-source merged historical reconstructions, analyses of the historical changes in fire emissions and their uncertainties, and quantification of the role of fire emissions in the Earth system. It also highlights the importance of accurately modeling the responses of fire emissions to LULCC and population density change in reducing uncertainties in historical reconstructions of fire emissions and providing more reliable future projections

Separating agricultural and non-agricultural fire seasonality at regional scales

The timing and length of burning seasons in different parts of the world depend on climate, land-cover characteristics, and human activities. In this study, global burned area estimates are used in conjunction with global gridded distributions of agricultural land-cover types (define as the sum of cropland and pasture area) to separate the seasonality of agricultural burning practices from that of non-agricultural fire The results presented in this study show that agricultural and non-agricultural land experience broadly different fir seasonality patterns that are not always linked to climate conditions. We highlight these differences on a regional basis, examining variations in both agricultural land cover and associated cultural practices to help explain our results. While we discuss two land-cover categories, the methods can be generalized to derive seasonality for any number of land uses or cover types. This will be useful as global fir models evolve to be fully interactive with land-use and land-cover change in the next generation of Earth system models

Quantifying regional, time-varying effects of cropland and pasture on vegetation fire

The global extent of agriculture demands a thorough understanding of the ways it impacts the Earth system through the modification of both the physical and biological characteristics of the landscape as well as through emissions of greenhouse gases and aerosols. People use fir to manage cropland and pasture in many parts of the world, impacting both the timing and amount of fire So far, much previous research into how these land uses affect fir regimes has focused on either individual small regions or global patterns at annual or decadal scales. Moreover, because pasture is not mapped globally at high resolution, the amount of fir associated with pasture has never been quantified as it has for cropland. The work presented here resolves the effects of agriculture – including pasture – on fir on a monthly basis for regions across the world, using globally gridded data on fir activity and land use at 0.25. The global extent of agriculture demands a thorough understanding of the ways it impacts the Earth system through the modification of both the physical and biological characteristics of the landscape as well as through emissions of greenhouse gases and aerosols. People use fir to manage cropland and pasture in many parts of the world, impacting both the timing and amount of fire So far, much previous research into how these land uses affect fir regimes has focused on either individual small regions or global patterns at annual or decadal scales. Moreover, because pasture is not mapped globally at high resolution, the amount of fir associated with pasture has never been quantified as it has for cropland. The work presented here resolves the effects of agriculture – including pasture – on fir on a monthly basis for regions across the world, using globally gridded data on fir activity and land use at 0.25 degrees resolution. The firs global estimate of pasture-associated fir reveals that it accounts for over 40 % of annual burned area. Cropland, generally assumed to reduce fir occurrence, is shown to enhance or suppress fir at different times of year within individual regions. These results bridge important gaps in the understanding of how agriculture and associated management practices influence vegetation fire enabling the next generation of vegetation and Earth system models more realistically incorporate these anthropogenic effects. resolution. The firs global estimate of pasture-associated fir reveals that it accounts for over 40 % of annual burned area. Cropland, generally assumed to reduce fir occurrence, is shown to enhance or suppress fir at different times of year within individual regions. These results bridge important gaps in the understanding of how agriculture and associated management practices influence vegetation fire enabling the next generation of vegetation and Earth system models more realistically incorporate these anthropogenic effects

Differential and shared genetic effects on kidney function between diabetic and non-diabetic individuals

A large-scale GWAS provides insight on diabetes-dependent genetic effects on the glomerular filtration rate, a common metric to monitor kidney health in disease.Reduced glomerular filtration rate (GFR) can progress to kidney failure. Risk factors include genetics and diabetes mellitus (DM), but little is known about their interaction. We conducted genome-wide association meta-analyses for estimated GFR based on serum creatinine (eGFR), separately for individuals with or without DM (n(DM) = 178,691, n(noDM) = 1,296,113). Our genome-wide searches identified (i) seven eGFR loci with significant DM/noDM-difference, (ii) four additional novel loci with suggestive difference and (iii) 28 further novel loci (including CUBN) by allowing for potential difference. GWAS on eGFR among DM individuals identified 2 known and 27 potentially responsible loci for diabetic kidney disease. Gene prioritization highlighted 18 genes that may inform reno-protective drug development. We highlight the existence of DM-only and noDM-only effects, which can inform about the target group, if respective genes are advanced as drug targets. Largely shared effects suggest that most drug interventions to alter eGFR should be effective in DM and noDM