TS.B Observed Impacts
Food systems, food security and forestry
TS.B.3 Climate change is already stressing food and forestry systems, with negative consequences for the livelihoods, food security and nutrition of hundreds of millions of people, especially in low and mid-latitudes (high confidence). The global food system is failing to address food insecurity and malnutrition in an environmentally sustainable way.
TS.B.3.5 The impacts of climate change on food systems affect everyone, but some groups are more vulnerable. Women, the elderly and children in low-income households, Indigenous Peoples, minority groups, small-scale producers and fishing communities and people in high-risk regions more often experience malnutrition, livelihood loss and rising costs (high confidence). Increasing competition for critical resources, such as land, energy and water, can exacerbate the impacts of climate change on food security (high confidence). Examples include large-scale land deals, water use, dietary patterns, energy crops and use of feed crops.
Water systems and water security
TS.B.4 Currently, roughly half of the world’s population are experiencing severe water scarcity for at least 1 month yr-1 due to climatic and other factors (medium confidence). Water insecurity is manifested through climate-induced water scarcity and hazards and is further exacerbated by inadequate water governance (high confidence). Extreme events and un- derlying vulnerabilities have intensified the societal impacts of droughts and floods, negatively impacted agriculture and energy production and increased the incidence of water-borne diseases. Economic and societal impacts of water insecurity are more pronounced in low-income countries than in middle- and high-income ones (high confidence).
TS.B.4.1 Climate change has intensified the global hydrological cycle, causing several societal impacts, which are felt disproportionately by vulnerable people (high confidence). Human-induced climate change has affected physical aspects of water security through increasing water scarcity and exposing more people to water-related extreme events like floods and droughts, thereby exacerbating existing water-related vulnerabilities caused by other socioeconomic factors (high confidence). Many of these changes in water availability and water-related hazards can be directly attributed to anthropogenic climate change (high confidence). Water insecurity disproportionately impacts the poor, women, children, Indigenous Peoples and the elderly in low-income countries (high confidence) and specific marginal geographies (e.g., small island states and mountain regions). Water insecurity can contribute to social unrest in regions where inequality is high and water governance and institutions are weak (medium confidence).
TS.B.4.4 Impacts of droughts and floods have intensified due to extreme events and underlying societal vulnerabilities (high confidence). Anthropogenic climate change has led to increased likelihood, severity and societal impacts of droughts (primarily agricultural and hydrological droughts) in many regions (high confidence). Between 1970 and 2019, drought-related disaster events worldwide caused billions of dollars in economic damages (medium confidence). Drylands are particularly exposed to climate change related droughts (high confidence). Recent heavy rainfall events that have led to catastrophic flooding were made more likely by anthropogenic climate change (high confidence). Observed mortality and losses due to floods and droughts are much greater in regions with high vulnerability and vulnerable populations such as the poor, women, children, Indigenous Peoples and the elderly due to historical, political and socioeconomic inequities (high confidence).
Health and well-being
TS.B.5 Climate change has already harmed human physical and mental health (very high confidence). In all regions, health impacts often undermine efforts for inclusive development. Women, children, the elderly, Indigenous People, low-income households and socially marginalised groups within cities, set- tlements, regions and countries are the most vulnerable (high confidence).
TS.B.5.2 Mental health challenges increase with warming temperatures (high confidence), trauma associated with extreme weather (very high confidence) and loss of livelihoods and culture (high confidence). Distress sufficient to impair mental health has been caused by climate-related ecological grief associated with environmental change (e.g., solastalgia) or extreme weather and climate events (very high confidence), vicarious experience or anticipation of climate events (medium confidence) and climate-related loss of livelihoods and food insecurity (very high confidence). Vulnerability to mental health effects of climate change varies by region and population, with evidence that Indigenous Peoples, agricultural communities, first responders, women and members of minority groups experience greater impacts (high confidence).
TS.B.5.3 Increasing temperatures and heatwaves have increased mortality and morbidity (very high confidence), with impacts that vary by age, gender, urbanisation and socioeconomic factors (very high confidence). A significant proportion of warm-season heat-related mortality in temperate regions is attributed to observed anthropogenic climate change (medium confidence), with fewer data available for tropical regions in Africa (high confidence). For some heatwave events over the last two decades, associated health impacts have been partially attributed to observed climate change (high confidence). Highly vulnerable groups experiencing health impacts from heat stress include anyone working outdoors and, especially, those doing outdoor manual labour (e.g., construction work, farming). Potential hours of work lost due to heat have increased significantly over the past two decades (high confidence). Some regions are already experiencing heat stress conditions at or approaching the upper limits of labour productivity (high confidence).
TS.B.5.4 Climate change has contributed to malnutrition in all its forms in many regions, including undernutrition, overnutrition and obesity, and to disease susceptibility (high confidence), especially for women, pregnant women, children, low-income households, Indigenous Peoples, minority groups and small-scale producers (high confidence). Extreme climate events have been key drivers in rising undernutrition of millions of people, primarily in Africa and Central America (high confidence). For example, anthropogenic warming contributed to climate extremes induced by the 2015–2016 El Niño, which resulted in severe droughts, leading to an additional 5.9 million children in 51 countries becoming underweight (high confidence). Undernutrition can in turn increase susceptibility to other health problems, including mental health problems, and impair cognitive and work performance, with resulting economic impacts (very high confidence). Children and pregnant women experience disproportionate adverse health and nutrition impacts (high confidence).
Human vulnerability
TS.B.7.1 About 3.3 billion people are living in countries with high human vulnerability to climate change (high confidence). Approximately 1.8 billion people reside in regions classified as having low vulnerability. Global concentrations of high vulnerability are emerging in transboundary areas encompassing more than one country as a result of interlinked issues concerning health, poverty, migration, conflict, gender inequality, inequity, education, high debt, weak institutions, lack of governance capacities and infrastructure. Complex human vulnerability patterns are shaped by past developments, such as colonialism and its ongoing legacy (high confidence), are worsened by compounding and cascading risks (high confidence) and are socially differentiated. For example, low-income, young, poor and female- headed households face greater livelihood risks from climate hazards (high confidence).
TS.B.8.3 Climate impacts on urban population health, livelihoods and well-being are felt disproportionately, with the most economically and socially marginalised being most affected (high confidence). Vulnerabilities vary by location and are shaped by intersecting processes of marginalization, including gender, class, race, income, ethnic origin, age, level of ability, sexuality and non- conforming gender orientation (high confidence).
Economic sectors
TS.B.9.3 Economic livelihoods that are more climate sensitive have been disproportionately degraded by climate change (high confidence). Climate-sensitive livelihoods are more concentrated in regions that have higher socioeconomic vulnerabilities and lower adaptive capacities, exacerbating existing inequalities (medium confidence). Extreme events have also had more pronounced adverse effects in poorer regions and on more vulnerable populations (medium confidence). These greater economic effects have further reduced the ability of these populations to adapt to existing impacts (medium confidence). Within populations, the poor, women, children, elderly and Indigenous populations have been especially vulnerable due to a combination of factors, including gendered divisions of paid and/ or unpaid labour (high confidence).
