Editing IPCC:AR6/SR15/Chapter-5 (section)

== 5.2 Poverty, Equality and Equity Implications of a 1.5°C Warmer World ==

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Climate change could lead to significant impacts on extreme poverty by 2030 (Hallegatte et al., 2016; Hallegatte and Rozenberg, 2017) <sup>[[#fn:r14|14]]</sup> . The AR5 concluded, with ''very high confidence'' , that climate change and climate variability worsen existing poverty and exacerbate inequalities, especially for those disadvantaged by gender, age, race, class, caste, indigeneity and (dis)ability (Olsson et al., 2014) <sup>[[#fn:r15|15]]</sup> . New literature on these links is substantial, showing that the poor will continue to experience climate change severely, and climate change will exacerbate poverty ( ''very high confidence'' ) (Fankhauser and Stern, 2016; Hallegatte et al., 2016; O’Neill et al., 2017a; Winsemius et al., 2018) <sup>[[#fn:r16|16]]</sup> . The understanding of regional impacts and risks of 1.5°C global warming and interactions with patterns of societal vulnerability and poverty remains limited. Yet identifying and addressing poverty and inequality is at the core of staying within a safe and just space for humanity (Raworth, 2017; Bathiany et al., 2018) <sup>[[#fn:r17|17]]</sup> . Building on relevant findings from Chapter 3 (see Section 3.4), this section examines anticipated impacts and risks of 1.5°C and higher warming on sustainable development, poverty, inequality and equity (see Glossary).

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=== 5.2.1 Impacts and Risks of a 1.5°C Warmer World: Implications for Poverty and Livelihoods ===

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Global warming of 1.5°C will have consequences for sustainable development, poverty and inequalities. This includes residual risks, limits to adaptation, and losses and damages (Cross-Chapter Box 12 in this chapter; see Glossary). Some regions have already experienced a 1.5°C warming, with impacts on food and water security, health and other components of sustainable development ( ''medium evidence, medium agreement'' ) (see Chapter 3, Section 3.4). Climate change is also already affecting poorer subsistence communities through decreases in crop production and quality, increases in crop pests and diseases, and disruption to culture (Savo et al., 2016) <sup>[[#fn:r18|18]]</sup> . It disproportionally affects children and the elderly and can increase gender inequality (Kaijser and Kronsell, 2014; Vinyeta et al., 2015; Carter et al., 2016; Hanna and Oliva, 2016; Li et al., 2016) <sup>[[#fn:r19|19]]</sup> .

At 1.5°C warming, compared to current conditions, further negative consequences are expected for poor people, and inequality and vulnerability ( ''medium evidence, high agreement'' ). Hallegatte and Rozenberg (2017) <sup>[[#fn:r20|20]]</sup> report that by 2030 (roughly approximating a 1.5°C warming), 122 million additional people could experience extreme poverty, based on a ‘poverty scenario’ of limited socio-economic progress, comparable to the Shared Socio-Economic Pathway (SSP) 4 (inequality), mainly due to higher food prices and declining health, with substantial income losses for the poorest 20% across 92 countries. Pretis et al. (2018) <sup>[[#fn:r21|21]]</sup> estimate negative impacts on economic growth in lower-income countries at 1.5°C warming, despite uncertainties. Impacts are likely to occur simultaneously across livelihood, food, human, water and ecosystem security ( ''limited evidence, high agreement'' ) (Byers et al., 2018) <sup>[[#fn:r22|22]]</sup> , but the literature on interacting and cascading effects remains scarce (Hallegatte et al., 2014; O’Neill et al., 2017b; Reyer et al., 2017a, b) <sup>[[#fn:r23|23]]</sup> .

Chapter 3 outlines future impacts and risks for ecosystems and human systems, many of which could also undermine sustainable development and efforts to eradicate poverty and hunger, and to protect health and ecosystems. Chapter 3 findings (see Section 3.5.2.1) suggest increasing Reasons for Concern from moderate to high at a warming of 1.1° to 1.6°C, including for indigenous people and their livelihoods, and ecosystems in the Arctic (O’Neill et al., 2017b) <sup>[[#fn:r24|24]]</sup> . In 2050, based on the Hadley Centre Climate Prediction Model 3 (HadCM3) and the Special Report on Emission Scenarios A1b scenario (roughly comparable to 1.5°C warming), 450 million more flood-prone people would be exposed to doubling in flood frequency, and global flood risk would increase substantially (Arnell and Gosling, 2016) <sup>[[#fn:r25|25]]</sup> . For droughts, poor people are expected to be more exposed (85% in population terms) in a warming scenario greater than 1.5°C for several countries in Asia and southern and western Africa (Winsemius et al., 2018) <sup>[[#fn:r26|26]]</sup> . In urban Africa, a 1.5°C warming could expose many households to water poverty and increased flooding (Pelling et al., 2018) <sup>[[#fn:r27|27]]</sup> . At 1.5ºC warming, fisheries-dependent and coastal livelihoods, of often disadvantaged populations, would suffer from the loss of coral reefs (see Chapter 3, Box 3.4).

Global heat stress is projected to increase in a 1.5°C warmer world, and by 2030, compared to 1961–1990, climate change could be responsible for additional annual deaths of 38,000 people from heat stress, particularly among the elderly, and 48,000 from diarrhoea, 60,000 from malaria, and 95,000 from childhood undernutrition (WHO, 2014) <sup>[[#fn:r28|28]]</sup> . Each 1°C increase could reduce work productivity by 1 to 3% for people working outdoors or without air conditioning, typically the poorer segments of the workforce (Park et al., 2015) <sup>[[#fn:r29|29]]</sup> .

The regional variation in the ‘warming experience at 1.5°C’ (see Chapter 1, Section 1.3.1) is large (see Chapter 3, Section 3.3.2). Declines in crop yields are widely reported for Africa (60% of observations), with serious consequences for subsistence and rain-fed agriculture and food security (Savo et al., 2016) <sup>[[#fn:r30|30]]</sup> . In Bangladesh, by 2050, damages and losses are expected for poor households dependent on freshwater fish stocks due to lack of mobility, limited access to land and strong reliance on local ecosystems (Dasgupta et al., 2017) <sup>[[#fn:r31|31]]</sup> . Small Island Developing States (SIDS) are expected to experience challenging conditions at 1.5°C warming due to increased risk of internal migration and displacement and limits to adaptation (see Chapter 3, Box 3.5, Cross-Chapter Box 12 in this chapter). An anticipated decline of marine fisheries of 3 million metric tonnes per degree warming would have serious regional impacts for the Indo-Pacific region and the Arctic (Cheung et al., 2016) <sup>[[#fn:r32|32]]</sup> .

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=== 5.2.2 Avoided Impacts of 1.5°C versus 2°C Warming for Poverty and Inequality ===

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Avoided impacts between 1.5°C and 2°C warming are expected to have significant positive implications for sustainable development, and reducing poverty and inequality. Using the SSPs (see Chapter 1, Cross-Chapter Box 1 in Chapter 1, Section 5.5.2), Byers et al. (2018) <sup>[[#fn:r33|33]]</sup> model the number of people exposed to multi-sector climate risks and vulnerable to poverty (income &lt; $10/day), comparing 2°C and 1.5°C; the respective declines are from 86 million to 24 million for SSP1 (sustainability), from 498 million to 286 million for SSP2 (middle of the road), and from 1220 million to 763 million for SSP3 (regional rivalry), which suggests overall 62–457 million fewer people exposed and vulnerable at 1.5°C warming. Across the SSPs, the largest populations exposed and vulnerable are in South Asia (Byers et al., 2018) <sup>[[#fn:r34|34]]</sup> . The avoided impacts on poverty at 1.5°C relative to 2°C are projected to depend at least as much or more on development scenarios than on warming (Wiebe et al., 2015; Hallegatte and Rozenberg, 2017) <sup>[[#fn:r35|35]]</sup> .

Limiting warming to 1.5°C is expected to reduce the number of people exposed to hunger, water stress and disease in Africa (Clements, 2009) <sup>[[#fn:r36|36]]</sup> . It is also expected to limit the number of poor people exposed to floods and droughts at higher degrees of warming, especially in African and Asian countries (Winsemius et al., 2018) <sup>[[#fn:r37|37]]</sup> . Challenges for poor populations – relating to food and water security, clean energy access and environmental well-being – are projected to be less at 1.5°C, particularly for vulnerable people in Africa and Asia (Byers et al., 2018) <sup>[[#fn:r38|38]]</sup> . The overall projected socio-economic losses compared to the present day are less at 1.5°C (8% loss of gross domestic product per capita) compared to 2°C (13%), with lower-income countries projected to experience greater losses, which may increase economic inequality between countries (Pretis et al., 2018) <sup>[[#fn:r39|39]]</sup> .

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=== 5.2.3 Risks from 1.5°C versus 2°C Global Warming and the Sustainable Development Goals ===

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The risks that can be avoided by limiting global warming to 1.5ºC rather than 2°C have many complex implications for sustainable development (ICSU, 2017; Gomez-Echeverri, 2018) <sup>[[#fn:r40|40]]</sup> . There is ''high confidence'' that constraining warming to 1.5°C rather than 2°C would reduce risks for unique and threatened ecosystems, safeguarding the services they provide for livelihoods and sustainable development and making adaptation much easier (O’Neill et al., 2017b) <sup>[[#fn:r41|41]]</sup> , particularly in Central America, the Amazon, South Africa and Australia (Schleussner et al., 2016; O’Neill et al., 2017b; Reyer et al., 2017b; Bathiany et al., 2018) <sup>[[#fn:r42|42]]</sup> .

In places that already bear disproportionate economic and social challenges to their sustainable development, people will face lower risks at 1.5°C compared to 2°C. These include North Africa and the Levant (less water scarcity), West Africa (less crop loss), South America and Southeast Asia (less intense heat), and many other coastal nations and island states (lower sea level rise, less coral reef loss) (Schleussner et al., 2016; Betts et al., 2018) <sup>[[#fn:r43|43]]</sup> . The risks for food, water and ecosystems, particularly in subtropical regions such as Central America and countries such as South Africa and Australia, are expected to be lower at 1.5°C than at 2°C warming (Schleussner et al., 2016) <sup>[[#fn:r44|44]]</sup> . Fewer people would be exposed to droughts and heat waves and the associated health impacts in countries such as Australia and India (King et al., 2017; Mishra et al., 2017) <sup>[[#fn:r45|45]]</sup> .

Limiting warming to 1.5°C would make it markedly easier to achieve the SDGs for poverty eradication, water access, safe cities, food security, healthy lives and inclusive economic growth, and would help to protect terrestrial ecosystems and biodiversity ( ''medium evidence, high agreement)'' (Table 5.2 available at the end of the chapter). For example, limiting species loss and expanding climate refugia will make it easier to achieve SDG 15 (see Chapter 3, Section 3.4.3). One indication of how lower temperatures benefit the SDGs is to compare the impacts of Representative Concentration Pathway (RCP) 4.5 (lower emissions) and RCP8.5 (higher emissions) on the SDGs (Ansuategi et al., 2015) <sup>[[#fn:r46|46]]</sup> . A low emissions pathway allows for greater success in achieving SDGs for reducing poverty and hunger, providing access to clean energy, reducing inequality, ensuring education for all and making cities more sustainable. Even at lower emissions, a medium risk of failure exists to meet goals for water and sanitation, and marine and terrestrial ecosystems.

Action on climate change (SDG 13), including slowing the rate of warming, would help reach the goals for water, energy, food and land (SDGs 6, 7, 2 and 15) (Obersteiner et al., 2016; ICSU, 2017) <sup>[[#fn:r47|47]]</sup> and contribute to poverty eradication (SDG 1) (Byers et al., 2018) <sup>[[#fn:r48|48]]</sup> . Although the literature that connects 1.5°C to the SDGs is limited, a pathway that stabilizes warming at 1.5°C by the end of the century is expected to increase the chances of achieving the SDGs by 2030, with greater potential to eradicate poverty, reduce inequality and foster equity ( ''limited evidence'' , ''medium agreement'' ). There are no studies on overshoot and dimensions of sustainable development, although literature on 4°C of warming suggests the impacts would be severe (Reyer et al., 2017b) <sup>[[#fn:r49|49]]</sup> .

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'''Table 5.1'''

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'''Sustainable development implications of avoided impacts between 1.5°C and 2°C global warming'''

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{| class="wikitable"
|-
! Impacts
! Chapter 3 Section
! 1.5°C
! 2°C
! Sustainable Development Goals (SDGs) More Easily Achieved when Limiting Warming to 1.5°C
|-
| rowspan="2"| Water scarcity
| 3.4.2.1
| 4% more people exposed to water stress
| 8% more people exposed to water stress, with 184–270 million people more exposed
| rowspan="2"| SDG 6 water availability for all
|-
| Table 3.4
| 496 (range 103–1159) million people exposed<br />
and vulnerable to water stress
| 586 (range 115–1347) million people exposed<br />
and vulnerable to water stress
|-
| rowspan="2"| Ecosystems
| 3.4.3,<br />
Table 3.4
| Around 7% of land area experiences biome<br />
shifts
| Around 13% (range 8–20%) of land area<br />
experiences biome shifts
| rowspan="2"| SDG 15 to protect terrestrial ecosystems<br />
and halt biodiversity loss
|-
| Box 3.5
| 70–90% of coral reefs at risk from bleaching
| 99% of coral reefs at risk from bleaching
|-
| rowspan="2"| Coastal cities
| 3.4.5.1
| 31–69 million people exposed to coastal<br />
flooding
| 32–79 million exposed to coastal flooding
| rowspan="2"| SDG 11 to make cities and human settlements safe and resilient
|-
| 3.4.5.2
| Fewer cities and coasts exposed to sea level rise<br />
and extreme events
| More people and cities exposed to flooding
|-
| rowspan="2"| Food systems
| 3.4.6,<br />
Box 3.1
| Significant declines in crop yields avoided,<br />
some yields may increase
| Average crop yields decline
| rowspan="2"| SDG 2 to end hunger and achieve food security
|-
| Table 3.4
| 32–36 million people exposed to lower yields
| 330–396 million people exposed to lower yields
|-
| rowspan="2"| Health
| 3.4.5.1
| Lower risk of temperature-related morbidity<br />
and smaller mosquito range
| Higher risks of temperature-related morbidity<br />
and mortality and larger geographic range<br />
of mosquitoes
| rowspan="2"| SDG 3 to ensure healthy lives for all
|-
| 3.4.5.2
| 3546–4508 million people exposed to heat waves
| 5417–6710 million people exposed to heat waves
|}
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