Key risks of climate change: Reasons for concern

Key risks of climate change: Reasons for concern Robert Kopp (robert.kopp@rutgers.edu) Rutgers Energy Institute May 4, 2016 Resources for the Future American Climate Prospectus: Economic Risks in the United States 10 East 40 th Street, Suite 3601, New York, NY 10016 Tel: +1.212.532.1158 Fax: +1.212.532.1162 Web: www.rhgroup.net #

IMPACTS CLIMATE Natural Variability RISK Vulnerability SOCIOECONOMIC PROCESSES Socioeconomic Pathways Anthropogenic Climate Change Hazards Key Emergent Adaptation and Mitigation Actions Governance Exposure EMISSIONS and Land-use Change Figure 19-1 Schematic of the interaction among the physical climate system, exposure, and vulnerability producing risk. The figure visualizes the different terms and concepts discussed in this chapter. Risk of climate-related impacts results from the interaction of climate-related hazards (including hazardous events and trends) with the vulnerability and exposure of human and natural systems. The definition and use of key and emergent are indicated in Box 19-2 and the Glossary. Vulnerability and exposure are, as the figure shows, largely the result of socioeconomic pathways and societal conditions (although changing hazard patterns also play a role; see Section 19.6.1.1). Changes in both the climate system (left side) and socioeconomic processes (right side) are central drivers of the different core components (vulnerability, exposure, and hazards) that constitute risk (modified version of SREX Figure SPM.1 (IPCC, 2012a)). AR5 WG2 ch. 19 2

Identifying key risks Key risks are potentially severe adverse consequences for humans and socialecological systems resulting from the interaction of climate-related hazards with vulnerabilities of societies and systems exposed. Risks are considered key due to high hazard or high vulnerability of societies and systems exposed, or both. Criteria: 1. Large magnitude, high probability, or irreversibility of impacts 2. Timing of impacts 3. Persistent vulnerability or exposure contribution to risks 4. Limited potential to reduce risks through adaptation or mitigation Reasons for Concern: 1. Risks to unique, threatened systems 2. Risks associated with extreme weather events 3. Risks associated with distribution of impacts 4. Risks associated with global aggregate impacts 5. Risks associated with large-scale singular events AR5 WG2 ch. 19 3

O Neill et al. (in rev.) 4

It s not just temperature O Neill et al. (in rev.), from AR5 Synthesis Report 5

It s not just temperature Subm O Neill et al. (in rev.), from AR5 Synthesis Report 6

As we ve learned more, risks generally perceived as higher Global mean temperature change ( C relative to 1986 2005) 5 4 3 2 1 0-0.61 C Risks to many, limited adaptation capacity Risks to some (RFC1) Risks to unique and threatened systems Severe and widespread impacts Moderate risk (RFC2) Risks associated with extreme weather events Increased risk for most regions Increased risk for some regions (RFC3) Risks associated with the distribution of impacts Risk of extensive biodiversity loss and global economic damages Loss to biodiversity and global economy. Positive and negative impacts (RFC4) Risks associated with global aggregate impacts Level of additional risk due to climate change High risk Low risk (RFC5) Risks associated with large-scale singular events 5 4 3 2 1 0 C ( C relative to 1850 1900, as an approximation of preindustrial levels) 2003 2012 Recent (1986 2005) Third Assessment Report (2001) White to yellow Yellow to red Red to purple White Yellow Red Purple Undetectable Moderate High Very high AR5 WG2 ch. 19 7

Risks depend on vulnerability, not just on physical change Global mean temperature change ( C relative to 1986 2005) 5 4 3 2 1 0-0.61 C B1, 2100 Low Burning Ember A2, 2050 Medium Exposure and vulnerability A2, 2100 A2, 2100 with mitigation High 5 4 3 2 1 0 C ( C relative to 1850 1900, as an approximation of preindustrial levels) 2003 2012 Recent (1986 2005) Level of additional risk due to climate change White to yellow Yellow to red Red to purple White Yellow Red Purple Undetectable Moderate High Very high AR5 WG2 ch. 19 8

Risk depends upon our mitigation choices O Neill et al. (in rev.) 9

Risk depends upon our mitigation choices 2016 O Neill et al. (in rev.) 9

Risk depends upon our mitigation choices Fossil-fuel intensive 2080-2099 (RCP 8.5) 2016 O Neill et al. (in rev.) 9

Risk depends upon our mitigation choices Fossil-fuel intensive 2080-2099 (RCP 8.5) Paris goal 2016 O Neill et al. (in rev.) 9

Overarching Key Risk i ii iii iv v vi vii viii O Neill et al. (in rev.) Reason for Concern Description 1 2 3 4 5 Risk of death, injury, ill-health, or disrupted livelihoods in lowlying coastal zones and small island developing states and other small islands, due to storm surges, coastal flooding, and sea level rise. Risk of severe ill-health and disrupted livelihoods for large urban populations due to inland flooding in some regions. Systemic risks due to extreme weather events leading to breakdown of infrastructure networks and critical services such as electricity, water supply, and health and emergency services. Risk of mortality and morbidity during periods of extreme heat, particularly for vulnerable urban populations and those working outdoors in urban or rural areas. Risk of food insecurity and the breakdown of food systems linked to warming, drought, flooding, and precipitation variability and extremes, particularly for poorer populations in urban and rural settings. Risk of loss of rural livelihoods and income due to insufficient access to drinking and irrigation water and reduced agricultural productivity, particularly for farmers and pastoralists with minimal capital in semi-arid regions. Risk of loss of marine and coastal ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for coastal livelihoods, especially for fishing communities in the tropics and the Arctic. Risk of loss of terrestrial and inland water ecosystems, biodiversity, and the ecosystem goods, functions, and services they provide for livelihoods. 12

Defining transitions in reasons for concern Undetectable to Moderate: at least medium confidence that impacts are both detectable and attributable to climate change, while also accounting for the magnitude of the risk and the other criteria noted above Moderate to High risk: impacts become severe and widespread High to Very High: risk is high according to all criteria and in particular the ability to adapt is limited O Neill et al. (in rev.) 13

Risks depend on vulnerability, not just on physical change O Neill et al. (in rev.) 14