scholarly journals Modelling the Ruin of Forests under Climate Hazards

2020 ◽  
Author(s):  
Pascal Yiou ◽  
Nicolas Viovy

Abstract. Estimating the risk of collapse of forests due to extreme climate events is one of the challenges of adaptation to climate change. We adapt a concept from ruin theory, which is widespread in econometrics or the insurance industry, to design a growth/ruin model for trees, under climate hazards that can jeopardize their growth. This model is an elaboration of a classical Cramer-Lundberg ruin model that is used in the insurance industry. The model accounts for the interactions between physiological parameters of trees and the occurrence of climate hazards. The physiological parameters describe interannual growth rates and how trees react to hazards. The hazard parameters describe the probability distributions of occurrence and intensity of climate events. We focus on a drought/heatwave hazard. The goal of the paper is to determine the dependence of ruin and average growth probability distributions as a function of physiological and hazard parameters. From extensive Monte Carlo experiments, we show the existence of a threshold on the frequency of hazards beyond which forest ruin becomes certain in a centennial horizon. We also detect a small effect of strategies to cope with hazards. This paper is a proof-of-concept to quantify collapse (of forests) under climate change.

2021 ◽  
Vol 12 (3) ◽  
pp. 997-1013
Author(s):  
Pascal Yiou ◽  
Nicolas Viovy

Abstract. Estimating the risk of forest collapse due to extreme climate events is one of the challenges of adapting to climate change. We adapt a concept from ruin theory, which is widely used in econometrics and the insurance industry, to design a growth–ruin model for trees which accounts for climate hazards that can jeopardize tree growth. This model is an elaboration of a classical Cramer–Lundberg ruin model that is used in the insurance industry. The model accounts for the interactions between physiological parameters of trees and the occurrence of climate hazards. The physiological parameters describe interannual growth rates and how trees react to hazards. The hazard parameters describe the probability distributions of the occurrence and intensity of climate events. We focus on a drought–heatwave hazard. The goal of the paper is to determine the dependence of the forest ruin and average growth probability distributions on physiological and hazard parameters. Using extensive Monte Carlo experiments, we show the existence of a threshold in the frequency of hazards beyond which forest ruin becomes certain to occur within a centennial horizon. We also detect a small effect of the strategies used to cope with hazards. This paper is a proof of concept for the quantification of forest collapse under climate change.


2021 ◽  
Author(s):  
Hans-Martin Füssel ◽  
Samuel Almond

<p>The Copernicus Climate Change Service’s (C3S) Climate Data Store (CDS) contains a wealth of information about the Earth's recent past, present and future climate. The CDS catalogue contains both general climate datasets, such as climate observations, seasonal forecasts, global and regional reanalyses and global and regional climate projections datasets, and in addition derived Climate Impact Indices<em> </em>(CII). CIIs are processed data which was developed to respond to specific sectoral needs. Most CII datasets were developed as part of the C3S Sectoral Information System (SIS) activities, which develops user-oriented products for various climate-sensitive sectors (e.g., water management, energy, biodiversity, human health and tourism).</p><p>The European Climate Data Explorer (ECDE) is a new web portal providing interactive access to selected climate variables and indices included in the CDS. It is hosted on the European Climate Adaptation Platform (Climate-ADAPT), a publicly accessible web portal managed by the European Environment Agency (EEA) in collaboration with the European Commission. The ECDE aims to facilitate access to a wide range of data on observed and projected climate change in Europe. Such data are relevant, among others, for developing and implementing national and subnational climate adaptation strategies and plans, including sectoral strategies.</p><p>The variables and indices currently included in the ECDE reflect user needs expressed through an EEA-led stakeholder consultation as well as data availability from C3S-led SIS contracts. The interactive access allows users to zoom in on maps in order to focus on regions of interest, show time series for specific countries and subnational regions (to NUTS level 3), and export images and data. The ECDE will be expanded further in response to user needs and increasing data availability in the CDS. This expansion will include additional sectoral indices as well as new data sources (e.g. from CMIP6).</p><p>The ECDE is complemented by the online EEA Report <em>Changing climate hazards in Europe</em> and a Technical Paper. These products provide further information on the underlying indices and datasets. The report also presents past and projected trends for key climate hazards across Europe.</p><p>The ECDE lowers the technical hurdles that limit access to CDS data for a large part of EEA’s target audience. Doing so, the ECDE supports the European Green Deal, including the new EU Strategy on Adaptation to Climate Change, and the EU Mission on Adaptation to climate change including societal transformation.</p>


Author(s):  
Boniface N. Wambua

The study was carried out in four selected counties within the Arid and Semi-Arid Lands (ASALS) of Kenya namely Garrisa, West Pokot, Kilifi and Tana River which were under Kenya-Adaptation to Climate Change in Arid Lands (KACCAL) program. The study focused on the current and potential future climate hazards and their impacts on livelihoods and adaptation strategies within the framework of Kenya – adaptation to climate change in arid lands. The ASALS covers 80% of Kenya’s land mass and support about 70 percent of the national livestock population and 90% of wildlife resources. Despite the great potential for development in the ASALS, the areas have continued experiencing great climate hazards leading to severe impacts on household livelihoods. The study methodology involved identification and assessing the major climatic hazards experienced for many years and implementation of adaptation strategies by the local communities. This involved a review of operating/ existing assessment of Climate Risks in Agriculture and Rural Development, Field visits, data collection and stakeholder consultation through a series of intensive questionnaire interviews with farmers, project Planners and managers and county officials in the four counties.The results showed that the four counties under study have been affected by droughts, floods, gusty winds and landslides hazards associated with climate change which have affected the livelihoods of the communities living in the ASALS. The impacts have been felt in food insecurity, scarcity of water resources, loss of livestock resources, persisted crop failure, increased malnutrition cases leading to infant morbidity and mortality among others. The intervention strategies to manage the climate change impacts  applied by stakeholders among other well-wishers are; distribution of food relief, provision of shelter, provision of tents, building gabions, moving families at high risk to saver grounds, construction of water dams and pans. At household level, intervention strategies used are diversification of livelihoods, growing of fodder crops to supplement the natural pasture, charcoal burning, growing of drought resistant crops among others. Subsequently, the study recommends that more awareness should be created among local communities so that they diversify their livelihoods to cope with changing climate. The stakeholder working in ASALs, County governments and National government should invest more on intervention strategies to management climate change impactsCommunities living in ASALs and other stakeholders should be trained on how to use tools and methodologies developed in order to monitor impacts of climate change in their respective counties and implement the appropriate intervention strategies to ensure households recover from impacts associated to of climate change. In other words, capacity building at community, county and national government should be a top priority.


Mousaion ◽  
2016 ◽  
Vol 33 (3) ◽  
pp. 1-24
Author(s):  
Emmanuel Elia ◽  
Stephen Mutula ◽  
Christine Stilwell

This study was part of broader PhD research which investigated how access to, and use of, information enhances adaptation to climate change and variability in the agricultural sector in semi-arid Central Tanzania. The research was carried out in two villages using Rogers’ Diffusion of Innovations theory and model to assess the dissemination of this information and its use by farmers in their adaptation of their farming practices to climate change and variability. This predominantly qualitative study employed a post-positivist paradigm. Some elements of a quantitative approach were also deployed in the data collection and analysis. The principal data collection methods were interviews and focus group discussions. The study population comprised farmers, agricultural extension officers and the Climate Change Adaptation in Africa project manager. Qualitative data were subjected to content analysis whereas quantitative data were analysed to generate mostly descriptive statistics using SPSS.  Key findings of the study show that farmers perceive a problem in the dissemination and use of climate information for agricultural development. They found access to agricultural inputs to be expensive, unreliable and untimely. To mitigate the adverse effects of climate change and variability on farming effectively, the study recommends the repackaging of current and accurate information on climate change and variability, farmer education and training, and collaboration between researchers, meteorology experts, and extension officers and farmers. Moreover, a clear policy framework for disseminating information related to climate change and variability is required.


2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Dibakar Mahanta ◽  
Jaideep Kumar Bisht ◽  
Lakshmi Kant ◽  
Arunava Pattanayak

Sign in / Sign up

Export Citation Format

Share Document