Smoke Hazard Assessment Model Based on Fire Dynamics Simulator and FED Model

Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable.

Assessment of climate damage in China based on integrated assessment framework

Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and adaptation.This study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs scenario.Employing a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate loss.The findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature rise.By 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,respectively.Additionally,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market sectors.From a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(18.6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.

Climate Warming Mitigation from Nationally Determined Contributions

Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly considered in the countries’decision-making process.In this study,we evaluate the global temperature slowdown of the NDC scenario(ΔT=0.6°C)and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions in CO_(2),CH_(4),N_(2)O,BC,and SO_(2),the R5OECD(the Organization for Economic Co-operation and Development in 1990)and R5ASIA(Asian countries)are the top two contributors to global warming mitigation,accounting for 39.3%and 36.8%,respectively.R5LAM(Latin America and the Caribbean)and R5MAF(the Middle East and Africa)followed behind,with contributions of 11.5%and 8.9%,respectively.The remaining 3.5%is attributed to R5REF(the Reforming Economies).Carbon Dioxide emission reduction is the decisive factor of regional contributions,but not the only one.Other greenhouse gases are also important,especially for R5MAF.The contribution of short-lived aerosols is small but significant,notably SO_(2)reduction in R5ASIA.We argue that additional species beyond CO_(2)need to be considered,including short-lived pollutants,when planning a route to mitigate climate change.It needs to be emphasized that there is still a gap to achieve the Paris Agreement 2-degree target with current NDC efforts,let alone the ambitious 1.5-degree target.All countries need to pursue stricter reduction policies for a more sustainable world.

A multi-model assessment of climate change damage in China and the world

Quantifying climate damage is essential to informing rational climate policies,but only a few studies have systematically compared the climate damage estimates made by different models,especially for China.In this study,we used three widely applied integrated assessment models-FUND,RICE,and PAGE-to estimate the damage under coupled shared socioeconomic pathways and representative concentration pathways(RCPs).Results show that the costs of climate damage constitute approximately 1.5%and 0.7%of China's GDP and global GDP per 1℃ temperature rise on average,respectively.Mitigation can reduce climate risk by lowering the average estimate and worst-case effects of climate damage.Compared with business-as-usual emissions(RCP8.5),the 2℃ target will reduce the average estimate of climate damage for China and the world by 93%and 87%,respectively,and by 80%and 84%,respectively,in the worst-case situation.Sectorial analysis of climate damage highlights the inconsistency of sector scope and significant parameter uncertainties in damage modules,requiring further improvement to integrate subfield research advances,particularly for damage related to rising sea levels and cooling energy demand.

Global climate damage in 2℃ and 1.5℃ scenarios based on BCC_SESM model in IAM framework

The quantitative functions for climate damages provide theoretical ground for the cost-benefit analysis in climate change economics,and they are also critical for linking climate module with economic module in the Integrated Assessment Models(IAMs).Nevertheless,it is necessary for IAMs to update sectoral climate impacts in order to catch up the advance in climate change studies.This study updates the sectoral climate damage function at global scale from climate Framework for Uncertainty,Negotiation and Distribution(FUND)model and develops the aggregate climate damage function in a bottom-up fashion.Besides conventional sectors such as agriculture,forestry,water resources,energy consumption and ecosystems,this study expands climate disaster types,assesses human health impacts caused by various air pollutants,and updates coastal damage by sea level rise.The Beijing Climate Center Simple Earth System Model(BCC_SESM)is used to project climate system based on Business-as-Usual(BAU)scenario,and the 2℃ and 1.5℃ scenarios based on RCPs and SSP2 databases.Sectoral results show that the agricultural sector is projected to suffer 63% of the total damage,followed by water resources(16%)and human health(12%)sectors in 2100.The regression results indicate that the aggregate climate damage function is in positive quadratic form for zero discounting.Under BAU scenario,the aggregate climate damage is projected to be 517.7 trillion USD during 2011-2100.Compared to that,the 2℃ and 1.5℃ scenarios are projected to respectively reduce climate damages by 215.6 trillion USD(approximately 41.6%)and 263.5 trillion USD(50.9%)in 2011-2100.

Modeling the implementation of NDCs and the scenarios below 2°C for the Belt and Road countries

In order to understand better on medium-and long-term climate change issues in international cooperation of the Belt and Road Initiative(BRI),this paper is meant to assess the implementation of National Determined Contributions(NDCs)of the BRI countries and the emission constraints under the Paris Agreement to hold the increase in the global average temperature to well below 2℃ above pre-industrial levels,based on the Belt and Road Integrated Assessment Model(BRIAM)and the best available data.The results show that the BRI countries are expected to collectively reduce about 3.2 billion tons of CO_(2)emissions with the implementation of their NDCs by 2030.In order to achieve the global goal of 2℃,without appropriate mitigation burden sharing and enhanced climate finance support,the BRI countries will face big challenges to bridge the emission gaps.The investment in clean energy and related new infrastructures in BRI will rise sharply to above US$100 trillion by the end of this century accordingly with the increase in carbon price,which will also eventually have a significant impact on the price of electricity and oversea freight transport in a connecting world.

Revisiting BCC-SESM parameters sensitivity with BCC-CSM1.1 co_(2)-concentration-driven simulations

Based on the results of the complex climate model BCC-CSM,the Beijing Climate Center Simple Earth System Model(BCC-SESM)was developed for climate system simulations in Integrated Assessment Models(IAMs).The first version of the BCC-SESM model was based on a high-emissions scenario(ESMRCP8.5)and tends to overestimate the temperatures in low and medium emissions scenarios.To address this problem,this study uses three CO_(2)-concentration-driven simulations under different RCP scenarios of complex climate models to evaluate parameters sensitivity and their impacts on projection efficacy.The results show that the new version of the BCC-SESM(denoted as BCC-SESM1.1)model based on a medium-emissions scenario experiment(RCP4.5)is more suitable for temperature projections for various climate scenarios.It can well reproduce the original value of complex climate model.At the same time,it also has high predictive efficacies for medium(RCP4.5)and low(RCP2.6)emissions scenarios,although it tends to underestimate for high emissions scenario(RCP8.5).The sensitivity tests for different RCP scenarios shows that the BCC-SESM1.1 has higher efficacy in projections of future climate change than those model versions based on the other scenarios.The projection deviations for the global average temperature by the BCC-SESM1.1(<2%)are better than the previous BCC-SESM(<5%).In light of recent progress in climate policy,the BCC-SESM1.1 is hence more suitable for coupling with IAMs for the purposes of assessing climate outcomes.

A U.S.‒China coal power transition and the global 1.5℃ pathway

As the world seeks to increase ambition rapidly to limit global warming to 1.5℃,joint leadership from the world's largest greenhouse gas(GHG)emitters-the United States(U.S.)and China-will be critical to deliver significant emissions reductions from their own countries as well as to catalyze increased international action.After a period of uncertainty in international climate policy,these countries now both have current leadership that supports ambitious climate action.In this context,a feasible,high-impact,and potentially globally catalytic agreement by the U.S.and China to transition away from coal to clean energy would be a major contribution toward this global effort.We undertake a plant-by-plant assessment in the power sector to identify practical coal retirement pathways for each country that are in line with national priorities and the global 1.5℃ target.Our plant-by-plant analysis shows that the 1.5℃-compatible pathways may result in an average retirement age of 47 years for the U.S.coal plants and 22 years for Chinese coal plants,raising important questions of how to compare broader economic,employment,and social impacts.We also demonstrate that such pathways would also lead to significant emissions reductions,lowering overall global energy-related CO_(2) emissions by about 9%in 2030 relative to 2020.A catalytic effect from the possibility of other countries taking compatible actions is estimated to reduce global emissions by 5.1 Gt CO_(2) in 2030 and by 10.1 Gt CO_(2) in 2045.