scholarly journals Attribution of the role of climate change in the forest fires in Sweden 2018

2021 ◽  
Vol 21 (7) ◽  
pp. 2169-2179
Author(s):  
Folmer Krikken ◽  
Flavio Lehner ◽  
Karsten Haustein ◽  
Igor Drobyshev ◽  
Geert Jan van Oldenborgh
Keyword(s):  
Climate Change ◽  
Confidence Interval ◽  
Forest Fires ◽  
Climate Models ◽  
Reanalysis Data ◽  
Fire Weather ◽  
Northern Sweden ◽  
Southern Sweden ◽  
Weather Risk

Abstract. In this study, we analyse the role of climate change in the forest fires that raged through large parts of Sweden in the summer of 2018 from a meteorological perspective. This is done by studying the Canadian Fire Weather Index (FWI) based on sub-daily data, both in reanalysis data sets (ERA-Interim, ERA5, the Japanese 55 year Reanalysis, JRA-55, and Modern-Era Retrospective analysis for Research and Applications version 2, MERRA-2) and three large-ensemble climate models (EC-Earth, weather@home, W@H, and Community Earth System Model, CESM) simulations. The FWI, based on reanalysis, correlates well with the observed burnt area in summer (r=0.6 to 0.8). We find that the maximum FWI in July 2018 had return times of ∼24 years (90 % CI, confidence interval, > 10 years) for southern and northern Sweden. Furthermore, we find a negative trend of the FWI for southern Sweden over the 1979 to 2017 time period in the reanalyses, yielding a non-significant reduced probability of such an event. However, the short observational record, large uncertainty between the reanalysis products and large natural variability of the FWI give a large confidence interval around this number that easily includes no change, so we cannot draw robust conclusions from reanalysis data. The three large-ensembles with climate models point to a roughly 1.1 (0.9 to 1.4) times increased probability (non-significant) for such events in the current climate relative to preindustrial climate. For a future climate (2 ∘C warming), we find a roughly 2 (1.5 to 3) times increased probability for such events relative to the preindustrial climate. The increased fire weather risk is mainly attributed to the increase in temperature. The other main factor, i.e. precipitation during summer months, is projected to increase for northern Sweden and decrease for southern Sweden. We, however, do not find a clear change in prolonged dry periods in summer months that could explain the increased fire weather risk in the climate models. In summary, we find a (non-significant) reduced probability of such events based on reanalyses, a small (non-significant) increased probability due to global warming up to now and a more robust (significant) increase in the risk for such events in the future based on the climate models.

scholarly journals Attribution of the role of climate change in the forest fires in Sweden 2018

2019 ◽  
Author(s):  
Folmer Krikken ◽  
Flavio Lehner ◽  
Karsten Haustein ◽  
Igor Drobyshev ◽  
Geert Jan van Oldenborgh
Keyword(s):  
Forest Fires ◽  
Climate Models ◽  
Reanalysis Data ◽  
The Other ◽  
Fire Weather ◽  
Northern Sweden ◽  
Southern Sweden ◽  
Increased Risk ◽  
Weather Risk

Abstract. In this study we analyse the role of climate change in the forest fires that raged through large parts of Sweden in the summer of 2018 from a meteorological perspective. This is done by studying the Canadian Fire Weather Index (FWI) based on sub-daily data, both in reanalysis datasets (ERA-Interim, ERA5, JMA55 and MERRA2) and three large ensemble climate models (EC-Earth, W@H and CESM) simulations. The FWI based on reanalysis correlates well with observed area burned in summer (r = 0.6 to 0.8). We find that the maximum forest fire risk in July 2018 had return times of ∼ 24 years for Southern and Northern Sweden. Further, we find a negative trend of the FWI for Southern Sweden over the 1979 to 2017 time period, yielding a decreasing risk of such an event solely based on reanalysis data. However, given the short observational record, large uncertainty between the reanalysis products and large natural variability of the FWI we cannot draw robust conclusions from reanalysis data. The 3 large-ensembles with climate models on the other hand point to a roughly 1.1 times increased risk for such events in the current climate relative to pre-industrial climate. For a future climate (2C warming) we find a roughly 2 times increased risk for such events relative to pre-industrial climate. The increased fire weather risk is mainly attributed to the increase in temperature. The other main factor, precipitation during summer months, is projected to increase for Northern Sweden, and decrease for Southern Sweden. We however do not find a clear change of prolonged dry periods in summer months that could explain the increased fire weather risk. In summary, we find a small but positive role of global warming up to now in the 2018 forest fires in Sweden, but a more robust increase in the risk for such events in the future.

scholarly journals Arctic Air Pollution: New Insights from POLARCAT-IPY

2014 ◽  
Vol 95 (12) ◽  
pp. 1873-1895 ◽  
Author(s):  
Katharine S. Law ◽  
Andreas Stohl ◽  
Patricia K. Quinn ◽  
Charles A. Brock ◽  
John F. Burkhart ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Fires ◽  
Tropospheric Ozone ◽  
Climate Models ◽  
The Arctic ◽  
International Polar Year ◽  
Ice Surface ◽  
Arctic Pollution ◽  
The Many

Given the rapid nature of climate change occurring in the Arctic and the difficulty climate models have in quantitatively reproducing observed changes such as sea ice loss, it is important to improve understanding of the processes leading to climate change in this region, including the role of short-lived climate pollutants such as aerosols and ozone. It has long been known that pollution produced from emissions at midlatitudes can be transported to the Arctic, resulting in a winter/spring aerosol maximum known as Arctic haze. However, many uncertainties remain about the composition and origin of Arctic pollution throughout the troposphere; for example, many climate–chemistry models fail to reproduce the strong seasonality of aerosol abundance observed at Arctic surface sites, the origin and deposition mechanisms of black carbon (soot) particles that darken the snow and ice surface in the Arctic is poorly understood, and chemical processes controlling the abundance of tropospheric ozone are not well quantified. The International Polar Year (IPY) Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, Climate, Chemistry, Aerosols and Transport (POLARCAT) core project had the goal to improve understanding about the origins of pollutants transported to the Arctic; to detail the chemical composition, optical properties, and climate forcing potential of Arctic aerosols; to evaluate the processes governing tropospheric ozone; and to quantify the role of boreal forest fires. This article provides a review of the many results now available based on analysis of data collected during the POLARCAT aircraft-, ship-, and ground-based field campaigns in spring and summer 2008. Major findings are highlighted and areas requiring further investigation are discussed.

scholarly journals Seasonal predictability of Mediterranean weather regimes in the Copernicus C3S systems

2021 ◽  
Author(s):  
Ignazio Giuntoli ◽  
Federico Fabiano ◽  
Susanna Corti
Keyword(s):  
Mediterranean Region ◽  
Climate Models ◽  
Reanalysis Data ◽  
Seasonal Predictability ◽  
Economic Implications ◽  
Weather Regimes ◽  
Weather Patterns ◽  
The Mediterranean ◽  
Good Agreement

AbstractSeasonal predictions in the Mediterranean region have relevant socio-economic implications, especially in the context of a changing climate. To date, sources of predictability have not been sufficiently investigated at the seasonal scale in this region. To fill this gap, we explore sources of predictability using a weather regimes (WRs) framework. The role of WRs in influencing regional weather patterns in the climate state has generated interest in assessing the ability of climate models to reproduce them. We identify four Mediterranean WRs for the winter (DJF) season and explore their sources of predictability looking at teleconnections with sea surface temperature (SST). In particular, we assess how SST anomalies affect the WRs frequencies during winter focussing on the two WRs that are associated with the teleconnections in which the signal is more intense: the Meridional and the Anticyclonic regimes. These sources of predictability are sought in five state-of-the-art seasonal forecasting systems included in the Copernicus Climate Change Services (C3S) suite finding a weaker signal but an overall good agreement with reanalysis data. Finally, we assess the ability of the C3S models in reproducing the reanalysis data WRs frequencies finding that their moderate skill increases during ENSO intense years, indicating that this teleconnection is well reproduced by the models and yields improved predictability in the Mediterranean region.

scholarly journals Attribution of the Australian bushfire risk to anthropogenic climate change

2020 ◽  
Author(s):  
Geert Jan van Oldenborgh ◽  
Folmer Krikken ◽  
Sophie Lewis ◽  
Nicholas J. Leach ◽  
Flavio Lehner ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Southern Annular Mode ◽  
Warming Trend ◽  
Anthropogenic Climate Change ◽  
Fire Season ◽  
Fire Weather ◽  
Weather Index ◽  
Fire Weather Index

Abstract. Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically-based index of fire weather, the Fire Weather Index, long-term observations of heat and drought, and eleven large ensembles of state-of-the-art climate models. In agreement with previous analyses we find that heat extremes have become more likely by at least a factor two due to the long-term warming trend. However, current climate models overestimate variability and tend to underestimate the long-term trend in these extremes, so the true change in the likelihood of extreme heat could be larger. We do not find an attributable trend in either extreme annual drought or the driest month of the fire season September–February. The observations, however, show a weak drying trend in the annual mean. Finally, we find large trends in the Fire Weather Index in the ERA5 reanalysis, and a smaller but significant increase by at least 30 % in the models. The trend is mainly driven by the increase of temperature extremes and hence also likely underestimated. For the 2019/20 season more than half of the July–December drought was driven by record excursions of the Indian Ocean dipole and Southern Annular Mode. These factors are included in the analysis. The study reveals the complexity of the 2019/20 bushfire event, with some, but not all drivers showing an imprint of anthropogenic climate change.

Effects of Hydrologic Model Choice and Calibration on the Portrayal of Climate Change Impacts

2015 ◽  
Vol 16 (2) ◽  
pp. 762-780 ◽  
Author(s):  
Pablo A. Mendoza ◽  
Martyn P. Clark ◽  
Naoki Mizukami ◽  
Andrew J. Newman ◽  
Michael Barlage ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Climate Models ◽  
Climate Change Impacts ◽  
Hydrologic Model ◽  
Global Climate Models ◽  
Change Scenario ◽  
Hydrologic Models ◽  
Climate System Model

Abstract The assessment of climate change impacts on water resources involves several methodological decisions, including choices of global climate models (GCMs), emission scenarios, downscaling techniques, and hydrologic modeling approaches. Among these, hydrologic model structure selection and parameter calibration are particularly relevant and usually have a strong subjective component. The goal of this research is to improve understanding of the role of these decisions on the assessment of the effects of climate change on hydrologic processes. The study is conducted in three basins located in the Colorado headwaters region, using four different hydrologic model structures [PRMS, VIC, Noah LSM, and Noah LSM with multiparameterization options (Noah-MP)]. To better understand the role of parameter estimation, model performance and projected hydrologic changes (i.e., changes in the hydrology obtained from hydrologic models due to climate change) are compared before and after calibration with the University of Arizona shuffled complex evolution (SCE-UA) algorithm. Hydrologic changes are examined via a climate change scenario where the Community Climate System Model (CCSM) change signal is used to perturb the boundary conditions of the Weather Research and Forecasting (WRF) Model configured at 4-km resolution. Substantial intermodel differences (i.e., discrepancies between hydrologic models) in the portrayal of climate change impacts on water resources are demonstrated. Specifically, intermodel differences are larger than the mean signal from the CCSM–WRF climate scenario examined, even after the calibration process. Importantly, traditional single-objective calibration techniques aimed to reduce errors in runoff simulations do not necessarily improve intermodel agreement (i.e., same outputs from different hydrologic models) in projected changes of some hydrological processes such as evapotranspiration or snowpack.

Large contribution from anthropogenic warming to an emerging North American megadrought

Science ◽  
2020 ◽  
Vol 368 (6488) ◽  
pp. 314-318 ◽  
Author(s):  
A. Park Williams ◽  
Edward R. Cook ◽  
Jason E. Smerdon ◽  
Benjamin I. Cook ◽  
John T. Abatzoglou ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
North America ◽  
Relative Humidity ◽  
Climate Models ◽  
Hydrological Modeling ◽  
Drought Severity ◽  
Large Contribution ◽  
Moderate Drought

Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming. Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 46% (model interquartiles of 34 to 103%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.

scholarly journals On the Attribution of a Single Event to Climate Change

2014 ◽  
Vol 27 (22) ◽  
pp. 8297-8301 ◽  
Author(s):  
Gerrit Hansen ◽  
Maximilian Auffhammer ◽  
Andrew R. Solow
Keyword(s):  
Climate Change ◽  
Confidence Interval ◽  
Recent Work ◽  
Extreme Weather ◽  
Historical Record ◽  
Attributable Risk ◽  
Extreme Weather Events ◽  
Single Event ◽  
Weather Events

Abstract There is growing interest in assessing the role of climate change in observed extreme weather events. Recent work in this area has focused on estimating a measure called attributable risk. A statistical formulation of this problem is described and used to construct a confidence interval for attributable risk. The resulting confidence is shown to be surprisingly wide even in the case where the event of interest is unprecedented in the historical record.

Fire weather risk assessment under climate change using a dynamical downscaling approach

2011 ◽  
Vol 26 (9) ◽  
pp. 1123-1133 ◽  
Author(s):  
A.C. Carvalho ◽  
A. Carvalho ◽  
H. Martins ◽  
C. Marques ◽  
A. Rocha ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Dynamical Downscaling ◽  
Fire Weather ◽  
Weather Risk

scholarly journals WOMEN’S ROLE IN MITIGATION AND DISASTER MANAGEMENT

2021 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Lilik Sumarni ◽  
Endang Rudiatin
Keyword(s):  
Climate Change ◽  
Natural Disasters ◽  
Disaster Management ◽  
Forest Fires ◽  
Disaster Mitigation ◽  
London School ◽  
Close Link ◽  
Role Of Women ◽  
The Impact

The impact of climate change caused by global warming is currently one of the trending topics in various media and it is an extremely serious threat to human security. Forest fires, floods, landslides and changes in lifestyles to survive natural disasters are the very significant contributing factors to poverty rates in various parts of the world. The London School of Economics and Political Science conducted a study of 141 countries affected by disasters in the 1981-2002 period and found a close link between natural disasters and women's socioeconomic status. Data from the National Agency for Disaster Management (BNPB) states that women have 14 times of risk for becoming victims of disasters compared to adult men. Women become the most victimized because women prioritize children and their families rather than saving themselves. Although women bear more risks to climate change, women can also have the principal opportunity and role in implementing climate change mitigation adaptation, namely by making women actors in disaster mitigation and drivers of change in parallel to their strong responsibilities to their families. By providing adequate knowledge for women about adaptation and mitigation of disasters, the women can turn themselves to be the strategic activists in coping with disasters for communities living in disaster-prone areas.This study is a comparative discussion of three research results to obtain an overview and find solutions to women's problems from the consequences of climate change, which is a study by changing women from being the most victims of natural disasters to becoming the driving actor for families and communities in overcoming disaster and her ability to survive the post-disaster situation. The conclusion is the three levels of gender roles related to climate change to increase women's adaptive capacity. An adaptation strategy needs the form of 1. Increasing the role of women in the political arena. It is a crucial issue because women's rights can be protected by their presence and role, as well as women in guarding policies. 2. Increasing the role of women in the realm of education. Education is no less important than politics because education will provide a foundation for understanding and self-confidence, bargaining and personal branding for women so that their presence in society will be recognized and will no longer be discriminated. 3. Cultural reconstruction based on gender equality is very important because so far, the notion of patriarchy is still inherent in our culture. Many perspectives are cooptated on the statement that superior (men) are stronger then give rise women mythos that is said to be weak (women). In reality, the presence of women is still fundamental to the aspect of maintaining the economy and education for the continuation and the quality of the life in the society.

scholarly journals Climate projections of a multi-variate heat stress index: the role of downscaling and bias correction

2019 ◽  
Author(s):  
Ana Casanueva ◽  
Sven Kotlarski ◽  
Sixto Herrera ◽  
Andreas M. Fischer ◽  
Tord Kjellstrom ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Bias Correction ◽  
Climate Models ◽  
Dew Point ◽  
Added Value ◽  
Stress Index ◽  
Corrected Data ◽  
Heat Stress Index

Abstract. Along with the higher demand of bias-corrected data for climate impact studies, the number of available data sets has largely increased in the recent years. For instance, the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) constitutes a framework for consistently projecting the impacts of climate change across affected sectors and spatial scales. These data are very attractive for any impact application since they offer worldwide bias-corrected data based on Global Climate Models (GCMs). Complementary, the CORDEX initiative has incorporated experiments based on regionally-downscaled bias-corrected data by means of debiasing and quantile mapping (QM) methods. In light of this situation, it is challenging to distil the most accurate and useful information for climate services, but at the same time it creates a perfect framework for intercomparison and sensitivity analyses. In the present study, the trend-preserving ISIMIP method and empirical QM are applied to climate model simulations that were carried out at different spatial resolutions (CMIP5 GCM and EURO-CORDEX Regional Climate Models (RCMs), at approximately 150 km, 50 km and 12 km horizontal resolution, respectively) in order to assess the role of downscaling and bias correction in a multi-variate framework. The analysis is carried out for the wet bulb globe temperature (WBGT), a heat stress index that is commonly used in the context of working people and labour productivity. WBGT for shaded conditions depends on air temperature and dew point temperature, which in this work are individually bias-corrected prior to the index calculation. Our results show that the added value of RCMs with respect to the driving GCM is limited after bias correction. The two bias correction methods are able to adjust the central part of the WBGT distribution, but some added value of QM is found in WBGT percentiles and in the intervariable relationships. The evaluation in present climate of such multivariate indices should be performed with caution since biases in the individual variables might compensate, thus leading to better performance for the wrong reason. Climate change projections of WBGT reveal a larger increase of summer mean heat stress for the GCM than for the RCMs, related to the well-known reduced summer warming of the EURO-CORDEX RCMs. These differences are lowered after QM, since this bias correction method modifies the change signals and brings the results for GCM and RCMs closer to each other. We also highlight the need of large ensembles of simulations to assess the feasibility of the derived projections.

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