Irrigation expansion onto rainfed croplands is an important part of the portfolio of agricultural measures, contributing to a more resilient crop production while enhancing agricultural yields. Existing global assessments of irrigation illustrate the biophysical potential, but generally do not account for socioeconomic and environmental constraints to irrigation deployment. Here we provide scenarios of regionalized sustainable irrigation expansion linked to socioeconomic projections from the Shared Socioeconomic Pathways framework, while accounting for biophysical irrigation limits. Under a Sustainability scenario, we find that sustainable irrigation could feed 2 billion people globally by 2100. With an additional 90 million people, sub-Saharan Africa is the region with the highest percentage increase in people fed via sustainable irrigation deployment. However, even under the most optimistic scenarios only half of the theoretically possible global biophysical irrigation potential would be utilized after accounting for socioeconomic constraints. Our results highlight the need for appropriate representation of socioeconomic factors in scenarios of future irrigation deployment.

The impacts of climate change are affecting human societies today. In parallel, socio-economic development has increased the capacity of countries around the global to adapt to those impacts although substantial challenges remain. Ongoing climate change will continue to result in a pressure to adapt, while socio-economic development could make it easier to do so. Countries’ effectiveness in fostering climate resilience will depend on the pace of both developments under different socio-economic and emission pathways. Here we assess trajectories of adaptation readiness in comparison with the continued emergence of hot days as a proxy for climate change hazards for different emission and socio-economic pathways over the 21st century. Putting the future evolution of both indices in relation to the observed dynamics over the recent past allows us to provide an assessment of the prospects of future climate resilience building beyond what has been experienced to date. We show that only an inclusive and sustainable stringent mitigation pathway allows for effective climate resilient development over the 21st century. Less inclusive or fossil-fuel driven development will not allow for improvements in resilience building beyond the recent past. Substantial differences emerge already in the 2020s. Our findings underscore the paramount importance of achieving the Paris Agreement goals to enable climate-resilient, sustainable development.

The extent to which societies will globally be able to adapt to climate change is not well understood. Here we analyze socioeconomic dimensions of adaptive capacity of populations to deal with heat stress and find income, urbanization and income inequality to be important factors in explaining adaptation to heat stress with air conditioning (AC). Using the scenario framework of the Shared Socioeconomic Pathways (SSPs), we estimate the future cooling gap, which represents the difference between the population exposed to heat stress and the population able to protect against heat stress with AC. Depending on the scenario of socioeconomic development, total population affected by the cooling gap may vary between 2 billion and 5 billion people in 2050, with the scenario-dependent range widening further towards the end of the century. Our analysis shows vast regional inequalities in adaptive capacity for one of the most universal manifestations of climate change, underscoring the need to account for the different potential levels of adaptive capacity in assessments of climate change impacts.

Gender inequalities are reflected in differential vulnerability, and exposure to the hazards posed by climate change and addressing them is key to increase the adaptive capacities of societies. We provide trajectories of the Gender Inequality Index (GII) alongside the Shared-Socioeconomic Pathways (SSPs), a scenario framework widely used in climate science. Here we find that rapid improvements in gender inequality are possible under a sustainable development scenario already in the near-term. The share of girls growing up in countries with the highest gender inequality could be reduced to about 24% in 2030 compared to about 70% today. Largely overcoming gender inequality as assessed in the GII would be within reach by mid-century. Under less optimistic scenarios, gender inequality may persist throughout the 21st century. Our results highlight the importance of incorporating gender in scenarios assessing future climate impacts and underscore the relevance of addressing gender inequalities in policies aiming to foster climate resilient development. Gender inequality increases vulnerability to climate change impacts and reduces societies’ adaptive capacity. Here the authors show how gender inequality may evolve in the future in five scenarios of socioeconomic development and highlight the importance of incorporating gender inequality in climate change research and policy.

Abstract. Current global mitigation ambition up to 2030 under the Paris Agreement, reflected in the National Determined Contributions (NDCs), is insufficient to achieve the agreement's 1.5  ∘ C long-term temperature limit. As governments are preparing new and updated NDCs for 2020, the question as to how much collective improvement is achieved is a pivotal one for the credibility of the international climate regime. The recent Special Report on Global Warming of 1.5  ∘ C by the Intergovernmental Panel on Climate Change has assessed a wide range of scenarios that achieve the 1.5  ∘ C limit. Those pathways are characterised by a substantial increase in near-term action and total greenhouse gas (GHG) emission levels about 50 % lower than what is implied by current NDCs. Here we assess the outcomes of different scenarios of NDC updating that fall short of achieving this 1.5  ∘ C benchmark. We find that incremental improvements in reduction targets, even if achieved globally, are insufficient to align collective ambition with the goals of the Paris Agreement. We provide estimates for global mean temperature increase by 2100 for different incremental NDC update scenarios and illustrate climate impacts under those median scenarios for extreme temperature, long-term sea-level rise and economic damages for the most vulnerable countries. Under the assumption of maintaining ambition as reflected in current NDCs up to 2100 and beyond, we project a reduction in the gross domestic product (GDP) in tropical countries of around 60 % compared to a no-climate-change scenario and median long-term sea-level rise of close to 2 m in 2300. About half of these impacts can be avoided by limiting warming to 1.5  ∘ C or below. Scenarios of more incremental NDC improvements do not lead to comparable reductions in climate impacts. An increase in aggregated NDC ambition of big emitters by 33 % in 2030 does not reduce presented climate impacts by more than about half compared to limiting warming to 1.5  ∘ C. Our results underscore that a transformational increase in 2030 ambition is required to achieve the goals of the Paris Agreement and avoid the worst impacts of climate change.

Abstract. Current global mitigation ambition as under the Paris Agreement as reflected in the National Determined Contributions (NDCs) up to 2030 is insufficient to achieve the Agreement's 1.5 °C long term temperature limit. As governments are preparing new and updated NDCs for 2020, the question as to how much collective improvement is achieved is a pivotal one for the credibility of the international climate regime. The recent Special Report of the Intergovernmental Panel of Climate Change on Global Warming of 1.5 °C has assessed a wide range of scenarios that achieve the 1.5 °C limit. Those pathways are characterized by a substantial increase in near-term action and total greenhouse gas (GHG) emission levels about 50 % lower than what is implied by current NDCs. Here we assess the outcomes of different scenarios of NDC updating that fall short of achieving this 1.5 °C benchmark. We find that incremental improvements in reduction targets even if achieved globally, are insufficient to align collective ambition with the goals of the Paris Agreement. We provide estimates for global mean temperature increase by 2100 for different incremental NDC update scenarios and illustrate climate impacts under those scenarios including for extreme temperature, long-term sea level rise and economic damages for the most vulnerable countries. Under the assumption of maintaining ambition as reflected in current NDCs up to 2100 and beyond, we project a reduction in the Gross Domestic Product (GDP) in tropical countries of about 50–60 % compared to a no-climate change scenario and long-term sea-level rise of close to 2 m in 2300. About half of these impacts can be avoided by limiting warming to 1.5 °C, or below. Scenarios of more incremental NDC improvements do not lead to comparable reductions in climate impacts. An increase in 2030 of the aggregated NDC ambition of big emitters by 33 % does not deliver more than about half the potential reduction in climate impacts compared to limiting warming to 1.5 °C. Our results underscore that a transformational increase in 2030 ambition is required to achieve the goals of the Paris Agreement and avoid the worst impacts of climate change.