Climate risk is the potential for problems for societies or ecosystems from the impacts of climate change. [2] The assessment of climate risk is based on formal analysis of the consequences, likelihoods and responses to these impacts. Societal constraints can also shape adaptation options. [3] [4] There are different values and preferences around risk, resulting in differences of risk perception. [5] : 149
Common approaches to risk assessment and risk management strategies are based on analysing hazards. This can also be applied to climate risk although there are distinct differences: The climate system is no longer staying within a stationary range of extremes. [6] Hence, climate change impacts are anticipated to increase for the coming decades. [7] There are also substantial differences in regional climate projections. These two aspects make it complicated to understand current and future climate risk around the world. Scientists use various climate change scenarios when they carry out climate risk analysis. [8]
The interaction of three risk factors define the degree of climate risk. They are hazards, vulnerability and exposure. [9] : 2417 There are various approaches to climate risk management. One example is climate risk insurance. This is a type of insurance designed to mitigate the financial and other risk associated with climate change, especially phenomena like extreme weather. [10] [11]
The IPCC Sixth Assessment Report defines climate risk is the potential for negative consequences for society or ecosystems from the impacts of climate change. [2] Risk is used mainly to talk about the potential effects of climate change, but it may also result from the measures that we take to respond to those changes. The definition also recognises the different values and preferences that people have towards the human or ecological systems at risk.
Risk assessment is the qualitative and/or quantitative scientific estimation of risks. [2]
Risk perception is the personal judgement that people make about the characteristics and severity of a risk. [2]
Climate risks are increasingly felt in all regions of the world, and they are especially visible in the growing number of disasters that are driven by climatic events. [9] Many of these risks and impacts are expected to increase in future, and therefore are an increasing concern. Risk assessments are based on responses of a climate system that is no longer staying within a stationary range of extremes. [6] The Intergovernmental Panel on Climate Change (IPCC) assessment framework is based on the understanding that climate risk emerges from the interaction of three risk factors: hazards, vulnerability and exposure.
In this framework, climate risks are also described in five sets of major risks: [9] : 2417
Risks and uncertainties are closely related concepts. Risk is “the potential” for a negative outcome, so it implies uncertainty or incomplete information. However, risks are more often understood in a more context-specific way. Each component of climate risk - hazards, exposure and vulnerability - may be uncertain in terms of the magnitude and likelihood of occurrence. Assessment of the risk includes a set of measured uncertainties. These are usually given in terms of a set or range of possible outcomes, which may also include probabilities. The IPCC uses qualitative rating scales for uncertainty which may be based on quantitative results or expert judgement. [2] : 2926 [12] : 11–12
Uncertainty is also used in a broader way to describe general lack of knowledge about the world and of possible outcomes (epistemic uncertainty). Some such outcomes are inherently unpredictable (aleatory uncertainty). It can also refer to different framings or understandings about the world (ambiguity) including different scientific understandings. There are many types of sources of uncertainty. Unlike risk, uncertainty does not always carry negative connotations. Risk is subcategory of uncertainty that is considered to make potential issues and problems more manageable. [12] : 11–12 [13] Risk is a term used widely across different management practice areas. Examples are business, economics, environment, finance, information technology, health, insurance, safety, and security.
Climate change vulnerability is a concept that describes how strongly people or ecosystems are likely to be affected by climate change. Its formal definition is the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans and also to natural systems (or ecosystems). [14] : 12 Issues around the capacity to cope and adapt are also part of this concept. [14] : 5 Vulnerability is a component of climate risk. Vulnerability differs within communities and also across societies, regions, and countries. It can increase or decrease over time. [14] : 12
Vulnerability is higher in some locations than in others. Certain regional factors increase vulnerability, namely poverty, bad governance and violent conflict. Also, some livelihoods are particularly climate-sensitive, and therefore are more vulnerable than others. Examples for climate-sensitive livelihoods are smallholder farmers, pastoralists and fishing communities. [14] : 12 In general, drivers for vulnerability of people and ecosystems are "unsustainable ocean and land use, inequity, marginalization, historical and ongoing patterns of inequity such as colonialism, and governance". [14] : 12Climate change adaptation and climate change mitigation can reduce climate-related risks. These two types of climate action can be complementary and can result in synergies, and thus more successful results. [5] : 128, 175
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Climate risk insurance is a type of insurance designed to mitigate the financial and other risk associated with climate change, especially phenomena like extreme weather. [21] [22] [23] The insurance is often treated as a type of insurance needed for improving the climate resilience of poor and developing communities. [24] [25] [26] It provides post-disaster liquidity for relief and reconstruction measures while also preparing for the future measures in order to reduce climate change vulnerability. Insurance is considered an important climate change adaptation measure.
Critics of the insurance, say that such insurance places the bulk of the economic burden on communities responsible for the least amount of carbon emissions. [25] For low-income countries, these insurance programmes can be expensive due to the high start-up costs and infrastructure requirements for the data collection. [27] It is theorised that high-premiums in high risk areas experiencing increased climate threats, would discourage settlement in those areas. [21] These programmes are also usually timely and financially inadequate, which could be an uncertainty to national budgets. [27] A considerable problem on a micro-level is that weather-related disasters usually affect whole regions or communities at the same time, resulting in a large number of claims simultaneously. [28] This means that it is needed to be sold on a very large, diversified scale. [28] However a well-designed climate risk insurance can act as a safety net for countries while improving resilience. [26] [29]Climate risks can be categorised into natural environment, infrastructure, human health, the built environment, business and international. [33] The IPCC Sixth Assessment Report considers risks within important sectors affected by climate change, like agriculture, water, cities, ecosystems, health and livelihoods. [34] : ix It also considers sets of major risks across these sectors. [9] : 2417 Risk categories are often assessed in relation to multiple hazards and impacts, but hazard-specific assessments are often also available, eg. flood risk or heatwave risk assessment.
The main risks to ecosystems from climate change are biodiversity loss, ecosystem structure change, increased tree mortality, increased wildfire, and ecosystem carbon losses. These risks are linked. Loss of species can increase the risks to ecosystem health. [35] : 279 Wildfire is an increasing risk for people as well as to ecosystems in many parts of the world. [35] : 290 Wildfires and increased pest infestations due to climate change caused much of the recent tree mortality in North America. [35] : 280
Risks to seas and coastal areas include coral bleaching linked with ocean warming. This can change the composition of ecosystems. Coral bleaching and mortality also increase the risks of flooding on nearby shorelines and islands. Ocean acidification attributed to climate change drives change in coral reefs and other ecosystems such as rocky shores and kelp forests. [36] : 142
Climate change-related risks to health include direct risks from extreme weather such as cold waves, storms, or prolonged high temperatures. There are also indirect risks such as mental health impacts of undernutrition or displacement caused by extreme weather. [37] : 1076 Similarly there are mental health risks from loss of access to green spaces, reduced air quality, or from anxiety about climate change. [37] : 1076, 1078 There are further risks from changes in conditions for transmission of infectious diseases. Malaria and dengue are particularly climate-sensitive. [37] : 1062
Rising temperatures and heatwaves are key risks for cities. With warmer temperatures the urban heat island effect is likely to get worse. Population growth and land use change will influence human health and productivity risks in cities. [38] : 993 Urban flooding is another key risk. This is especially the case in coastal settlements where flood risks are exacerbated by sea-level rise and storm surges. A further set of risks arises from reduced water availability. When supply cannot meet demand from expanding settlements, urban residents become exposed to water insecurity and climate impacts. This is especially so during periods of lower rainfall. These key risks differ greatly between cities, and between different groups of people in the same city. [38] : 993
Climate change is affecting the overall and seasonal availability of water across regions. Climate change is projected to increase the variability of rain. There will be impacts on water quality as well as quantity. Floods can wash pollutants into water bodies and damage water infrastructure. In many places, particularly in the tropics and sub-tropics, there are longer dry spells and droughts, sometimes over consecutive years. These have contributed to drier soil conditions, lower groundwater tables and reduced or changed flows of rivers. There are risks to ecosystems, and across many water-using sectors of the economy. [39] : 660 Agriculture is likely to be affected by changes in water availability, putting food security at risk. Irrigation has often contributed to groundwater depletion and changes in the water cycle. It can sometimes make a drought worse. [40] : 1157
Climate change affects livelihoods and living conditions in significant ways. These include access to natural resources and ecosystems, land and other assets. Access to basic infrastructure services such as water and sanitation, electricity, roads, telecommunications is another aspect of vulnerability of communities and livelihoods to climate change. [41] : 1119
The biggest livelihood-related risks stem from losses of agricultural yields, impacts on human health and food security, destruction of homes, and loss of income. There are also risks to fish and livestock that livelihoods depend on. [41] : 1178 Some communities and livelihoods also face risks of irreversible losses and challenges to development, as well as more complex disaster risks. [41] : 1214
The consequences of climate change are the most severe for the poorest populations. These are disproportionately more exposed to hazards such as temperature extremes and droughts. They usually have fewer resources and assets and less access to funding, support and political influence. There are other forms of disadvantage due to discrimination, gender inequalities and through lack of access to resources This includes people with disabilities or minority groups. [41] : 1251
In 2020 the World Economic Forum ranked climate change as the biggest risk to economy and society. [42] Companies face reputational risks as well as financial risks. [43] Companies publicly criticised for their environmental policies or high emissions might lose customers because of negative reputation. [44]
International climate risks are climate risks that cross national borders. Sometimes the impacts of climate change in one country or region can have further consequences for people in other countries. Risks can spread from one country to a neighbouring country, or from one country to distant regions. Risks can also cascade and have knock-on effects elsewhere, across multiple borders and sectors. For example, an impact of the floods in Thailand in 2011 was disruption to manufacturing supply chains affecting the automotive sector and electronics industry in Japan, Europe and the USA. [9] : 2441–2444 [45]
The different stages in a supply chain, where risks can be transmitted and managed, is an example of a risk pathway. Risk pathways, via which impacts are transmitted, include trade and finance networks, flows of people, resource flows such as water or food, and ecosystem connections. [9] : 2441–2444 [45]
International risks potentially could affect small trade-dependent countries especially those dependent on food imports. They could also affect richer, developed nations that are relatively less exposed to direct risks from climate change. In addition, there are potential consequences from adaptation responses initiated in one country that might transmit or alter risks elsewhere. For example, a decision to pull out of investment in risky markets may increase climate vulnerability for many communities. [45]
The Intergovernmental Panel on Climate Change (IPCC) assessment framework is based on the understanding that climate risk emerges from the interaction of three risk factors: hazards, vulnerability and exposure. One of primary roles of the IPCC, which was created by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988, is to evaluate climate risks and explore strategies for their prevention and publish this knowledge each year in a series of comprehensive reports. [46] The most recent report to consider the widest set of climate risks across nature and human activity was the Sixth Assessment Report Working Group II report Impacts, Adaptation and Vulnerability , published in 2022. The assessed levels of risk generally increased compared to previous reports, whilst the impacts were found to have been on the high end of what had been expected.
The European Climate Risk Assessment (EUCRA) will assess current and future climate change impacts and risks relating to the environment, economy and wider society in Europe. The European Commission’s Directorate-General for Climate Action and the EEA lead the preparation. The EUCRA is expected to be published in Spring 2024. [47]
The National Climate Assessment (NCA) is a United States government interagency ongoing effort on climate change science conducted under the auspices of the Global Change Research Act of 1990. The fourth edition 'Volume II: Impacts, Risks, and Adaptation in the United States' was published in 2018. [48]
The UK Government is required, under the 2008 Climate Change Act, to publish a Climate Change Risk Assessment every five years. This assessment sets out the risks and opportunities facing the UK from climate change. The third assessment published in 2022 identified 61 risks cutting across multiple sectors. These risks were categorised into natural environment, infrastructure, human health, the built environment, business and international. [33]
The Climate Change Response (Zero Carbon) Amendment Act (amended 2019) includes the publication of a National Climate Change Risk Assessment, every six years. The First Assessment (2020) grouped risks according to five value domains: human, natural environment, economy, built environment and governance. The assessment details the 10 most urgent risks overall, among them: risks to potable water supplies (availability and quality), risks to buildings due to extreme weather events, and risks to governments from economic costs of lost productivity, disaster relief and other unforeseen expenditures. [49]
Waterborne diseases are conditions caused by pathogenic micro-organisms that are transmitted by water. These diseases can be spread while bathing, washing, drinking water, or by eating food exposed to contaminated water. They are a pressing issue in rural areas amongst developing countries all over the world. While diarrhea and vomiting are the most commonly reported symptoms of waterborne illness, other symptoms can include skin, ear, respiratory, or eye problems. Lack of clean water supply, sanitation and hygiene (WASH) are major causes for the spread of waterborne diseases in a community. Therefore, reliable access to clean drinking water and sanitation is the main method to prevent waterborne diseases.
Climate change adaptation is the process of adjusting to the effects of climate change. These can be both current or expected impacts. Adaptation aims to moderate or avoid harm for people, and is usually done alongside climate change mitigation. It also aims to exploit opportunities. Humans may also intervene to help adjustment for natural systems. There are many adaptation strategies or options. They can help manage impacts and risks to people and nature. The four types of adaptation actions are infrastructural, institutional, behavioural and nature-based options.
Adaptive capacity relates to the capacity of systems, institutions, humans and other organisms to adjust to potential damage, to take advantage of opportunities, or to respond to consequences. In the context of ecosystems, adaptive capacity is determined by genetic diversity of species, biodiversity of particular ecosystems in specific landscapes or biome regions. In the context of coupled socio-ecological social systems, adaptive capacity is commonly associated with the following characteristics: Firstly, the ability of institutions and networks to learn, and store knowledge and experience. Secondly, the creative flexibility in decision making, transitioning and problem solving. And thirdly, the existence of power structures that are responsive and consider the needs of all stakeholders.
Tanbi Wetland Complex is a wetland reserve in the Gambia outside of Banjul which was established in 2001.
Kalissaye Avifaunal Reserve (KAR) is a small nature reserve in Senegal, located at the mouth of Kalissaye Pond in the middle of the Casamance River.
Saloum Delta National Park or Parc National du Delta du Saloum in Senegal, is a 760-square-kilometre (190,000-acre) national park. Established in 1976, it is situated within the Saloum Delta at the juncture of the Saloum River and the North Atlantic.
The Island of Saint-Louis is the historic part of the city of Saint-Louis in Senegal. In 2000, it was inscribed by the UNESCO on the World Heritage list.
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech.
The Cacheu River Mangroves Natural Park is a national park situated on the Cacheu River in Guinea-Bissau. It was established on 1 December 2000. This site is 886 km2. The park has been designated as a Ramsar site since 2015.
The Marromeu Game Reserve is a protected swath of 1,500 square kilometres (580 sq mi) of floodplain in the Zambezi, the only such area along the river. The reserve is characterized by vast grasslands and numerous rivers and streams. The African elephant, Lichtenstein's hartebeest, sable antelope, eland, burchell's zebra, hippopotamus, waterbuck, and reedbuck are all found there. Wild dogs, lions, leopards, cheetahs, and spotted hyenas are all predators. The Marromeu National Park is actively working to repopulate the area with buffalo after their population dwindled to 30,000. From the border of the buffalo reserve into the neighbouring Cheringoma highlands, a hunting concession of 8,252 square kilometres surrounds the Marromeu Complex, which consists of the 1,500-square-kilometer Marromeu Special Reserve. It was dedicated on 1 January 1969. It is located near Beira.
The effects of climate change on human health are increasingly well studied and quantified. Rising temperatures and changes in weather patterns are increasing the severity of heat waves, extreme weather and other causes of illness, injury or death. Heat waves and extreme weather events have a big impact on health both directly and indirectly. When people are exposed to higher temperatures for longer time periods they might experience heat illness and heat-related death.
Loss and damage is a concept to describe results from the adverse effects of climate change and how to deal with them. There has been slow progress on implementing mitigation and adaptation. Some losses and damages are already occurring, and further loss and damage is unavoidable. There is a distinction between economic losses and non-economic losses. The main difference between the two is that non-economic losses involve things that are not commonly traded in markets.
Climate resilience is a concept to describe how well people or ecosystems are prepared to bounce back from certain climate hazard events. The formal definition of the term is the "capacity of social, economic and ecosystems to cope with a hazardous event or trend or disturbance". For example, climate resilience can be the ability to recover from climate-related shocks such as floods and droughts. Methods of coping include suitable responses to maintain relevant functions of societies and ecosystems. To increase climate resilience means one has to reduce the climate vulnerability of people and countries. Efforts to increase climate resilience include a range of social, economic, technological, and political strategies. They have to be implemented at all scales of society, from local community action all the way to global treaties.
Community resilience is the sustained ability of a community to use available resources to respond to, withstand, and recover from adverse situations. This allows for the adaptation and growth of a community after disaster strikes. Communities that are resilient are able to minimize any disaster, making the return to normal life as effortless as possible. By implementing a community resilience plan, a community can come together and overcome any disaster, while rebuilding physically and economically.
The Medina of Sousse is a Medina quarter in Sousse, Governorate of Sousse, Tunisia. Designated by the UNESCO a World Heritage Site in 1988, it is a typical example of the architecture of the early centuries of Islam in Maghreb. It encompasses a Kasbah, fortifications and the Great Mosque of Sousse. The Medina today houses the Archaeological Museum of Sousse. A number of Punic steles were discovered in the Medina, between the Ribat and the Great Mosque, in the 19th and 20th centuries.
Nature-based solutions is the sustainable management and use of natural processes to tackle socio-environmental issues. These issues include for example climate change mitigation and adaptation, water security, and disaster risk reduction. The aim is that resilient ecosystems provide solutions for the benefit of both societies and biodiversity. The 2019 UN Climate Action Summit highlighted nature-based solutions as an effective method to combat climate change. For example, nature-based systems for climate change adaptation can include natural flood management, restoring natural coastal defences, and providing local cooling.
A marine heatwave is a period of abnormally high seawater temperatures compared to the typical temperatures in the past for a particular season and region. Marine heatwaves are caused by a variety of drivers. These include shorter term weather events such as fronts, intraseasonal events, annual, and decadal (10-year) modes like El Niño events, and human-caused climate change. Marine heatwaves affect ecosystems in the oceans. For example, marine heatwaves can lead to severe biodiversity changes such as coral bleaching, sea star wasting disease, harmful algal blooms, and mass mortality of benthic communities. Unlike heatwaves on land, marine heatwaves can extend over vast areas, persist for weeks to months or even years, and occur at subsurface levels.
Climate change vulnerability is a concept that describes how strongly people or ecosystems are likely to be affected by climate change. Its formal definition is the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans and also to natural systems. Issues around the capacity to cope and adapt are also part of this concept. Vulnerability is a component of climate risk. Vulnerability differs within communities and also across societies, regions, and countries. It can increase or decrease over time.
Koko Warner is a climate change expert who specializes in human migration and displacement and who holds a PhD in economics from the University of Vienna. In 2014, the International Council for Science named Warner as one of the top 20 women making contributions to climate change debate.
The time value of carbon is a conjecture that there is a greater benefit from reducing carbon dioxide or other greenhouse gas reduction immediately than reducing the same amount of emissions in the future. According to this conjecture, carbon emissions are subject to a discount rate, similar to money, which means that the timing of carbon emissions is important to consider alongside their magnitude. This is not to be confused with the monetary discount rate applied to carbon emission or carbon sequestration projects. Rather, it is a discount rate applied to the physical carbon itself.