Keywan Riahi

Keywan Riahi
International Institute for Applied Systems Analysis | IIASA · Energy Program

About

328
Publications
194,870
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54,645
Citations
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January 2008 - December 2012
Graz University of Technology

Publications

Publications (328)
Article
Full-text available
In rural sub-Saharan Africa – the global poverty hotspot – the vast majority of cropland is rainfed only, resulting in reduced and unstable yields. Smallholder farmers account for 80% of agricultural production but they have limited access to relevant services to support both commercial operations and their livelihoods: more than two-thirds of rura...
Article
Full-text available
A significant energy transition is taking place worldwide, driven by the expanding capacity of renewable energy sources like wind and solar energy. Due to their inherent variability, these renewable energy sources must have accessible energy storage options. This article suggests using a gravitational-based energy storage method consisting of sand,...
Article
Full-text available
Indus River Basin (IRB) region of South Asia is severely water-stressed with irrigation receiving 90–95% of total surface water allocations and depletion of fossil groundwater reserves of more than 30 km3/year. Simultaneously, many supply-driven hydropower reservoirs, are planned in the basin. The reservoirs constructed upstream inflict severe envi...
Article
Full-text available
Keywords: Energy storage Seasonal pumped hydropower storage Water management Renewable energy systems Energy policy Electricity storage Energy model A B S T R A C T Central Asia has faced major energy and water security challenges. Technically, water from the Pamir and Tian Shan Mountain ranges could be sufficient to meet the needs of the countries...
Article
As they gain new users, climate change mitigation scenarios are playing an increasing role in transitions to net zero. One promising practice is the analysis of scenario ensembles. Here we argue that this practice has the potential to bring new and more robust insights compared with the use of single scenarios. However, several important aspects ha...
Article
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The world is undergoing a transition to a more sustainable energy sector dominated by renewable energy sources, which is increasing the need for long-term energy storage alternatives. This paper proposes an innovative energy storage solution that consists of transporting sand from a lower to an upper storage site at the top of a mountain or pit min...
Book
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The Working Group III (WG III) contribution to the IPCC’s Sixth Assessment Report (AR6) assesses literature on the scientific, technological, environmental, economic and social aspects of mitigation of climate change. The report reflects new findings in the relevant literature and builds on previous IPCC reports, including the WG III contribution t...
Article
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The world is undergoing a rapid energy transformation dominated by growing capacities of renewable energy sources, such as wind and solar power. The intrinsic variable nature of such renewable energy sources calls for affordable energy storage solutions. This paper proposes the use of lifts and empty apartments in tall buildings to store energy. Li...
Article
Full-text available
The world is undergoing a substantial energy transition with an increasing share of intermittent sources of energy on the grid such as wind and solar. These variable renewable energy sources require an energy storage solution to allow a smooth integration of these sources. Batteries can provide short-term storage solutions. However, there is still...
Article
With the establishment of the sustainable development goals (SDGs), countries worldwide agreed to a prosperous, socially inclusive, and environmentally sustainable future for all. This ambition, however, exposes a critical gap in science-based insights, namely on how to achieve the 17 SDGs simultaneously. Quantitative goal-seeking scenario studies...
Article
Projections of greenhouse gas (GHG) emissions are critical to enable a better understanding and anticipation of future climate change under different socioeconomic conditions and mitigation strategies. The climate projections and scenarios assessed by the Intergovernmental Panel on Climate Change, following the Shared Socioeconomic Pathway (SSP)-Re...
Article
Full-text available
Delaying climate mitigation action and allowing a temporary overshoot of temperature targets require large-scale carbon dioxide removal (CDR) in the second half of this century that may induce adverse side effects on land, food and ecosystems. Meanwhile, meeting climate goals without global net-negative emissions inevitably needs early and rapid em...
Article
Full-text available
The COVID-19 pandemic caused radical temporary breaks with past energy use trends. How post-pandemic recovery will impact the longer-term energy transition is unclear. Here we present a set of global COVID-19 shock-and-recovery scenarios that systematically explore the effect of demand changes persisting. Our pathways project final energy demand re...
Article
Full-text available
Mitigation pathways exploring end-of-century temperature targets often entail temperature overshoot. Little is known about the additional climate risks generated by overshooting temperature. Here we assessed the benefits of limiting overshoot. We computed the probabilistic impacts for different warming targets and overshoot levels on the basis of a...
Article
Full-text available
Global emissions scenarios play a critical role in the assessment of strategies to mitigate climate change. The current scenarios, however, are criticized because they feature strategies with pronounced overshoot of the global temperature goal, requiring a long-term repair phase to draw temperatures down again through net-negative emissions. Some i...
Article
Full-text available
Closing the emissions gap between Nationally Determined Contributions (NDCs) and the global emissions levels needed to achieve the Paris Agreement’s climate goals will require a comprehensive package of policy measures. National and sectoral policies can help fill the gap, but success stories in one country cannot be automatically replicated in oth...
Preprint
Projections of greenhouse gas (GHG) emissions are critical to better understanding and anticipating future climate change under different socio-economic conditions and mitigation strategies. The climate projections and scenarios assessed by the Intergovernmental Panel on Climate Change, following the Shared Socioeconomic Pathway (SSP)-Representativ...
Article
Full-text available
In recent years, there has been growing interest in defining what exactly constitutes “decent living standards” (DLS)—the material underpinnings of human well-being. We assess the gaps in providing decent health, shelter, nutrition, socialization, and mobility within countries, across the world. Our results show that more people are deprived of DLS...
Article
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Approaches that integrate feedback between climate, land, energy and water (CLEW) have progressed significantly in scope and complexity. The so-called nexus approaches have shown their usefulness in assessing strategies to achieve the Sustainable Development Goals in the contexts of increasing demands, resource scarcity, and climate change. However...
Article
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The Paris Agreement does not only stipulate to limit the global average temperature increase to well below 2 °C, it also calls for 'making finance flows consistent with a pathway towards low greenhouse gas emissions'. Consequently, there is an urgent need to understand the implications of climate targets for energy systems and quantify the associat...
Article
Full-text available
Long-term mitigation scenarios developed by integrated assessment models underpin major aspects of recent IPCC reports and have been critical to identify the system transformations that are required to meet stringent climate goals. However, they have been criticized for proposing pathways that may prove challenging to implement in the real world an...
Article
National-level climate actions will be vital in achieving global temperature goals in the coming decades. Near-term (2025–2030) plans are laid out in Nationally Determined Contributions; the next step is the submission of long-term strategies for 2050. At present, national scenarios underpinning long-term strategies are poorly coordinated and incom...
Article
The financial system-the ecosystem of investors (e.g., banks, investment funds, insurance), markets, and instruments-is often considered to play an enabling role in climate mitigation pathways to a low-carbon transition (1). But it can also have a hampering role, e.g., if investors' perceptions of low risk from a missed transition and low opportuni...
Article
Full-text available
With a rapidly growing population of 250 million, the Indus river basin in South Asia is one of the most intensively cultivated regions on Earth, highly water stressed and lacking energy security. Yet, most studies advising sustainable development policy have lacked multi-sectoral and cross-country perspectives. Here we show how the countries in th...
Preprint
This page belonged to the preprint version. Published version now available at: http://dx.doi.org/10.1088/1748-9326/ac1c27
Article
Full-text available
A Correction to this paper has been published: https://doi.org/10.1038/s41558-020-00981-9.
Article
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The Scenario Model Intercomparison Project (ScenarioMIP) defines and coordinates the main set of future climate projections, based on concentration-driven simulations, within the Coupled Model Intercomparison Project phase 6 (CMIP6). This paper presents a range of its outcomes by synthesizing results from the participating global coupled Earth syst...
Preprint
Full-text available
The COVID-19 pandemic caused radical temporary breaks with past energy use trends. However, how a post-pandemic recovery will impact the longer-term energy transition is unclear. Here, we present a set of global COVID-19 shock-and-recovery scenarios that systematically explore the demand-side effect on final energy and GHG emissions. Our pathways p...
Article
Full-text available
The Energy Modeling Forum inter-comparison study on short-lived climate forcers (EMF-30) focuses on black carbon (BC) and methane (CH4), two of the most important warming SLCFs. The study is aimed at quantifying the potential impact of methane and BC-focused reductions on climate change and at comparing the impact of idealized SLCF reductions as co...
Preprint
Allowing delayed climate mitigation actions and overshoot of temperature targets requires large scale negative carbon emissions that may induce adverse side-effects on land, food and ecosystems in the second half of this century. Meanwhile, meeting climate goals without net negative emissions inevitably needs the implementation of early and quick e...
Preprint
Full-text available
Global emissions scenarios play a critical role in the assessment of strategies to mitigate climate change and their related societal transformations. The current generation of scenarios, however, are criticized because they rely heavily on net negative CO2 emissions (NNCE) that result from allowing temperature limits to be temporarily exceeded. In...
Preprint
Full-text available
Closing the remaining emissions gap between Nationally Determined Contributions (NDCs) and the global emissions levels needed to achieve the Paris Agreement’s climate goals will likely require a comprehensive package of policy measures. National and sectoral policies can help fill the gap, but success stories in one country cannot be automatically...
Article
Long-term global scenarios have underpinned research and assessment of global environmental change for four decades. Over the past ten years, the climate change research community has developed a scenario framework combining alternative futures of climate and society to facilitate integrated research and consistent assessment to inform policy. Here...
Article
Full-text available
Several studies have shown that the greenhouse gas reduction resulting from the current nationally determined contributions (NDCs) will not be enough to meet the overall targets of the Paris Climate Agreement. It has been suggested that more ambition mitigations of short-lived climate forcer (SLCF) emissions could potentially be a way to reduce the...
Article
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The relatively short atmospheric lifetimes of methane (CH 4) and black carbon (BC) have focused attention on the potential for reducing anthropogenic climate change by reducing Short-Lived Climate Forcer (SLCF) emissions. This paper examines radiative forcing and global mean temperature results from the Energy Modeling Forum (EMF)-30 multi-model su...
Article
Full-text available
Human land use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth’s surface, with consequences for climate and other ecosystem services. In the future, land use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the World Clima...
Technical Report
Full-text available
CD-LINKS insights critically informed the Intergovernmental Panel on Climate Change (IPCC) special report on Global Warming of 1.5°C, as well as other reports on the assessment of investment and finance needs. Through continued inter-disciplinary global research efforts such as CD-LINKS, we can strategically and systematically work to achieve objec...
Preprint
Full-text available
To feed a rapidly growing population of 250 million, the Indus river basin in South Asia is one of the most intensively cultivated regions on Earth, highly water stressed and lacking energy security. Yet, most studies advising sustainable development policy have lacked multi-sectoral and cross-country perspectives. Here we show how the Indus countr...
Article
Full-text available
This paper explores the consequences of different policy assumptions and the derivation of globally consistent, national low-carbon development pathways for the seven largest greenhouse gas (GHG)–emitting countries (EU28 as a bloc) in the world, covering approximately 70% of global CO2 emissions, in line with their contributions to limiting global...
Preprint
Full-text available
The Scenario Model Intercomparison Project (ScenarioMIP) defines and coordinates the primary future climate projections within the Coupled Model Intercomparison Project Phase 6 (CMIP6). This paper presents a range of its outcomes by synthesizing results from the participating global coupled Earth system models for concentration driven simulations....
Article
Full-text available
To halt climate change this century, we must reduce carbon dioxide (CO2) emissions from human activities to net zero. Any emission sources, such as in the energy or land-use sectors, must be balanced by natural or technological carbon sinks that facilitate CO2 removal (CDR) from the atmosphere. Projections of demand for large-scale CDR are based on...
Article
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Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario a...
Preprint
Full-text available
Abstract. Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with consequences for climate and other ecosystem services. In the future, land-use activities are likely to expand and/or intensify further to meet growing demands for food, fiber, and energy. As part of the Wor...
Article
Full-text available
The energy–water–land nexus represents a critical leverage future policies must draw upon to reduce trade-offs between sustainable development objectives. Yet, existing long-term planning tools do not provide the scope or level of integration across the nexus to unravel important development constraints. Moreover, existing tools and data are not al...
Article
Full-text available
Seasonal mismatches between electricity supply and demand is increasing due to expanded use of wind, solar and hydropower resources, which in turn raises the interest on low-cost seasonal energy storage options. Seasonal pumped hydropower storage (SPHS) can provide long-term energy storage at a relatively low-cost and co-benefits in the form of fre...
Article
Exploring potential future pathways for developing Asia’s energy consumption, CO2 emissions and infrastructure investment needs is essential to understanding how the countries of this rapidly growing region may contribute to the global climate targets set out in the 2015 Paris Agreement. To this end, this study employs the state-of-the-art global i...
Article
The world is undergoing an energy transition with the inclusion of intermittent sources of energy in the grid. These variable renewable energy sources require energy storage solutions to be integrated smoothly over different time steps. In the near future, batteries can provide short-term storage solutions and pumped-hydro storage can provide long-...
Article
Future emissions scenarios for the IPCC Sixth Assessment Report should explore the carbon budget space in a systematic manner, which would be robust to the updates of latest climate science, so that policy implications can be adequately assessed.
Article
Full-text available
Increasing human demands for water, energy, food and materials, are expected to accentuate resource supply challenges over the coming decades. Experience suggests that long-term strategies for a single sector could yield both trade-offs and synergies for other sectors. Thus, long-term transition pathways for linked resource systems should be inform...
Article
Full-text available
The Indus River Basin covers an area of around 1 million square kilometers and connects four countries: Afghanistan, China, India, and Pakistan. More than 300 million people depend to some extent on the basin’s water, yet a growing population, increasing food and energy demands, climate change, and shifting monsoon patterns are exerting increasing...
Article
Full-text available
To understand how global warming can be kept well below 2 degrees Celsius and even 1.5 degrees Celsius, climate policy uses scenarios that describe how society could reduce its greenhouse gas emissions. However, current scenarios have a key weakness: they typically focus on reaching specific climate goals in 2100. This choice may encourage risky pa...
Preprint
The energy-water-land nexus represents a critical leverage future policies must draw upon to reduce trade-offs between sustainable development objectives. Yet, existing long-term planning tools do not provide the scope or level of integration across the nexus to unravel important development constraints. Moreover, existing tools and data are not al...