Ken Caldeira

Ken Caldeira
Gates Ventures LLC

PhD. Request papers by emailing kcaldeira@carnegiescience.edu

About

444
Publications
150,459
Reads
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Introduction
A scientist researching issues related to climate, carbon, and energy. Carnegie Institution for Science (Global Ecology), Stanford, CA 94305, USA. Please request papers by emailing: kcaldeira@carnegiescience.edu. https://dge.carnegiescience.edu/labs/caldeira-lab
Additional affiliations
July 2005 - present
Carnegie Institution for Science
September 1993 - June 2005
September 1991 - August 1993
Pennsylvania State University
Position
  • PostDoc Position

Publications

Publications (444)
Article
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Carbon dioxide emissions from deforestation disturbance (e.g., clear-cutting, forest fires) are in the same units as carbon dioxide emissions from fossil fuels. However, if the forest is allowed to regrow, there is a large difference between climate effects of that forest disturbance and climate effects of fossil CO 2 . In this study, using a set o...
Article
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New designs of advanced nuclear power plants have been proposed that may allow nuclear power to be less expensive and more flexible than conventional nuclear. It is unclear how and whether such a system would complement variable renewables in decarbonized electricity systems. Here we modelled stylized electricity systems under a least-cost optimiza...
Article
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Policies in the US increasingly stipulate the use of variable renewable energy sources, which must be able to meet electricity demand reliably and affordably despite variability. The value of grid services provided by additional marginal capacity and storage in existing grids is likely very different than their value in a 100% variable renewable el...
Article
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Solar photovoltaics, with sufficient power generation potential, low-carbon footprint, and rapidly declining costs, could supplant fossil fuel uses and help produce lower-cost net-zero emissions energy systems. Here we used an idealized linear optimization model, including free lossless transmission, to study the response of electricity systems to...
Article
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Wind and solar photovoltaic generators are projected to play important roles in achieving a net-zero-carbon electricity system that meets current and future energy needs. Here, we show potential advantages of long-term site planning of wind and solar power plants in deeply decarbonized electricity systems using a macro-scale energy model. With weak...
Article
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Electricity systems worldwide are transforming from relying almost exclusively on firm, predictable generation (e.g., fossil, nuclear, and large hydropower) towards incorporating more variable generation (e.g., wind and solar PV). In these systems, the electric load minus generation from variable resources is known as the “residual load.” The peak...
Article
Electric sector capacity expansion models are widely used by academic, government, and industry researchers for policy analysis and planning. Many models overlap in their capabilities, spatial and temporal resolutions, and research purposes, but yield diverse results due to both parametric and structural differences. Previous work has attempted to...
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We performed spectral analyses on the ages of 89 well-dated major geological events of the last 260 Myr from the recent geologic literature. These events include times of marine and non-marine extinctions, major ocean-anoxic events, continental flood-basalt eruptions, sea-level fluctuations, global pulses of intraplate magmatism, and times of chang...
Conference Paper
Hundreds of gigawatts of renewable technologies, such as wind and solar, need to be installed to reach a zero-carbon electricity system that meets current and future energy needs. Locations of new installations are typically chosen based on wind and solar availability to maximize facilities’ capacity factors. Here, we show that this is not always t...
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If future net-zero emissions energy systems rely heavily on solar and wind resources, spatial and temporal mismatches between resource availability and electricity demand may challenge system reliability. Using 39 years of hourly reanalysis data (1980–2018), we analyze the ability of solar and wind resources to meet electricity demand in 42 countri...
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Wind and solar electricity generation is projected to expand substantially over the next several decades due both to rapid cost declines as well as regulation designed to achieve climate targets. With increasing reliance on wind and solar generation, future energy systems may be vulnerable to previously underappreciated synoptic-scale variations ch...
Article
Variability of wind and solar generation and electricity demand poses substantial challenges to the affordable supply of reliable electricity. In a modeling study published in Energy & Environmental Science, Guerra and colleagues find that a portfolio of energy storage technologies provides the least-cost path to reliable electricity supply.
Article
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Variable, low-cost, low-carbon electricity that would otherwise be curtailed may provide a substantial economic opportunity for entities that can flexibly adapt their electricity consumption. We used historical hourly weather data over the contiguous U.S. to model the characteristics of least-cost electricity systems dominated by variable renewable...
Preprint
Full-text available
Wind and solar electricity generation is projected to expand substantially over the next several decades due both to rapid cost declines as well as regulation designed to achieve climate targets. With increasing reliance on wind and solar generation, future energy systems may be vulnerable to previously underappreciated synoptic-scale variations ch...
Article
As reliance on wind and solar power for electricity generation increases, so does the importance of understanding how variability in these resources affects the feasible, cost-effective ways of supplying energy services. We use hourly weather data over multiple decades and historical electricity demand data to analyze the gaps between wind and sola...
Article
Our circular-spectral and Fourier analyses of the ages of the 10 recognized non-marine tetrapod extinction events over the last 300 My revealed a significant spectral peak at 27.5 My. Omerbashich, using his Gauss-Vaniçek method of spectral analysis, fails to find a significant 27.5 My cycle in the same data. He claims to find predominant short (< 1...
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Global and local anthropogenic stressors such as climate change, acidification, overfishing, and pollution are expected to shift the benthic community composition of coral reefs from dominance by calcifying organisms to dominance by non‐calcifying algae. These changes could reduce the ability of coral reef ecosystems to maintain positive net calciu...
Article
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Solar radiation modification has been suggested as a backup option to reduce anthropogenic warming. Marine cloud brightening (MCB) and ocean albedo modification (OAM) are two proposed approaches to intentionally reflect sunlight back to space over oceanic regions. Using the NCAR Community Earth System Model, we compare climate response to MCB and O...
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Non-marine tetrapods (amphibians, reptiles, birds and mammals) have apparently experienced at least 10 distinct episodes of intensified extinctions over the past 300 My. Eight of these ten non-marine extinction events are concurrent with known marine-extinction episodes, which previously yielded evidence for an underlying period of ~26.4 to 27.3 My...
Article
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To reduce atmospheric carbon dioxide emissions and mitigate impacts of climate change, countries across the world have mandated quotas for renewable electricity. But a question has remained largely unexplored: would low-cost, firm, zero-carbon electricity generation technologies enhance—or would they displace—deployment of variable renewable electr...
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Decarbonizing the energy system is a major challenge facing the richest countries, whereas provision of energy services is a major challenge facing the poorest countries. What would be the climate consequences if only richer countries focus on decarbonization, and only poorer countries focus on provision of energy services? To address this question...
Article
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Facing severe air pollution issues, China has implemented a series of clean air policies aimed to improve the country's air quality. These policies largely focused on reducing emissions of major air pollutants such as sulfur dioxide (SO2) and primary aerosols. However, changes in such pollution also affect radiative forcing. To understand the clima...
Article
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Global climate change mitigation is often framed in public discussions as a tradeoff between environmental protection and harm to the economy. However, climate-economy models have consistently calculated that the immediate implementation of greenhouse gas emissions restriction (via e.g. a global carbon price) would be in humanity’s best interest on...
Article
Reliable and affordable electricity systems based on variable energy sources, such as wind and solar may depend on the ability to store large quantities of low-cost energy over long timescales. Here, we use 39 years of hourly U.S. weather data, and a macro-scale energy model to evaluate capacities and dispatch in least cost, 100% reliable electrici...
Article
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We use 36 years (1980-2015) of hourly weather data over the contiguous United States (CONUS) to assess the impact of low-cost energy storage on highly reliable electricity systems that use only variable renewable energy (VRE; wind and solar photovoltaics). Even assuming perfect transmission of wind and solar generation aggregated over CONUS, energy...
Article
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Spectral analyses of past relative sea-level oscillations as represented by the ages of 57 Phanerozoic (the last 545 Myr) stratigraphic sequence boundaries from the Canadian Arctic show a strong spectral peak at 32 Myr (>99.9% confidence). These findings concur with previous reports of significant cycles with periods of around 30 Myr in various rec...
Article
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Abstract Global mean surface air temperature (Tglobal) variability on subdecadal timescales can be of substantial magnitude relative to the long‐term global warming signal, and such variability has been associated with considerable environmental and societal impacts. Therefore, probabilistic foreknowledge of short‐term Tglobal evolution may be of v...
Article
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Electricity usage (demand) data are used by utilities, governments, and academics to model electric grids for a variety of planning (e.g., capacity expansion and system operation) purposes. The U.S. Energy Information Administration collects hourly demand data from all balancing authorities (BAs) in the contiguous United States. As of September 201...
Article
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A number of radiation modification approaches have been proposed to counteract anthropogenic warming by intentionally altering Earth's shortwave or longwave fluxes. While several previous studies have examined the climate effect of different radiation modification approaches, only a few have investigated the carbon cycle response. Our study examine...
Article
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The climate effects of anthropogenic aerosols have masked some of the warming induced by GHGs1 along with some impacts of that warming2. These temperature effects may be beneficial but are almost certainly overwhelmed by aerosols’ negative health impacts3. Recent analyses of economic impacts have concluded that warming harms economies in warm clima...
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Understanding the extent to which laboratory findings of low pH on marine organisms can be extrapolated to the natural environment is key towards making better projections on the impacts of global change on marine ecosystems. We simultaneously exposed larvae of the sea urchin Arbacia lixula to ocean acidification in laboratory and natural CO2 vents...
Article
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Abstract Solar geoengineering by deliberate injection of sulfate aerosols in the stratosphere is one of the proposed options to counter anthropogenic climate warming. In this study, we focus on the effect of a specific microphysical property of sulfate aerosols in the stratosphere: hygroscopic growth—the tendency of particles to grow by accumulatin...
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Hypoxia, a condition of low dissolved oxygen concentration, is a widespread problem in marine and freshwater ecosystems. To date, prevention and mitigation of hypoxia has centered on nutrient reduction to prevent eutrophication. However, nutrient reduction is often slow and sometimes insufficient to remedy hypoxia. We investigate the utility of a c...
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Reduction of surface temperatures of the planet by injecting sulfate aerosols in the stratosphere has been suggested as an option to reduce the amount of human-induced climate warming. Several previous studies have shown that for a specified amount of injection, aerosols injected at a higher altitude in the stratosphere would produce more cooling b...
Article
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Climate change is causing major changes to marine ecosystems globally, with ocean acidification of particular concern for coral reefs. Using a 200 d in situ carbon dioxide enrichment study on Heron Island, Australia, we simulated future ocean acidification conditions, and found reduced pH led to a drastic decline in net calcification of living cora...
Article
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Plain Language Summary Major volcanic eruptions are considered as natural analogues for stratospheric sulfate aerosol geoengineering that aims to cool the climate by increasing the burden of stratospheric sulfate aerosols. Volcanic eruptions produce a layer of sulfate aerosols that stays in the stratosphere for a couple of years, whereas geoenginee...
Article
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Net anthropogenic carbon dioxide (CO2) emissions must approach zero by mid-century (2050) to stabilize global mean temperature at the levels targeted by international efforts1–5. Yet continued expansion of fossil-fuel energy infrastructure implies already ‘committed’ future CO2 emissions6–13. Here we use detailed datasets of current fossil-fuel-bur...
Article
Induced energy-saving efficiency improvements strongly influence energy use and climate change. This mechanism has previously been studied by bottom-up methods in models, but the effect is debatable because of lack of empirical data needed to calibrate model parameters. We provide a top-down calibration of the relation between historical rates of v...
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In the version of this Article originally published, owing to a code error, the CSCC values for all income-dependent (that is, rich-poor) impact model specifications were incorrect, showing higher values relative to the preferred model rather than lower. These have now been recalculated for BHM SR RP, BHM LR RP and DJO RP, and Figs 1, 2b and 3b, as...
Article
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Reduction of surface temperatures of the planet by injecting sulfate aerosols in the stratosphere has been suggested as an option to reduce the amount of human-induced climate warming. Several previous studies have shown that for a specified amount of injection, aerosols injected at a higher altitude in the stratosphere would produce more cooling b...
Article
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We examine the potential for climate change to impact fertility via adaptations in human behavior. We start by discussing a wide range of economic channels through which climate change might impact fertility, including sectoral reallocation, the gender wage gap, longevity, and child mortality. Then, we build a quantitative model that combines stand...
Article
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Carbon fluxes on coral reefs (net community production and net community calcification) aggregate the collective activity of all coral reef community members. This integrated approach provides powerful community-level insights, but is unable to resolve the finer-scale contributions of different reef functional groups to the community-scale rates. T...
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In this study, we use the National Center for Atmospheric Research Community Earth System Model to investigate the contribution of sea ice and land snow to the climate sensitivity in response to increased atmospheric carbon dioxide content. We focus on the overall effect arising from the presence or absence of sea ice and/or land snow. We analyze o...
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Aerosol–cloud radiative effects are determined and quantified in simulations of deep open-cell stratocumuli observed during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) campaign off the west coast of Chile. The cloud deck forms in a boundary layer 1.5km deep, with cell sizes reaching 50km in diameter. Global database...
Article
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In this study, using idealized step-forcing simulations, we examine the effective radiative forcing of CH4 relative to that of CO2 and compare the effects of CH4 and CO2 forcing on the climate system. A tenfold increase in CH4 concentration in the NCAR CAM5 climate model produces similar long term global mean surface warming (~ 1.7 K) as a one-thir...
Article
Geoengineering has been proposed as a backup approach to rapidly cool the Earth and avoid damages associated with anthropogenic climate change. In this study, we use the NCAR Community Earth System Model to conduct a series of slab-ocean and prescribed sea surface temperature simulations to investigate the climate response to three proposed radiati...
Article
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The social cost of carbon (SCC) is a commonly employed metric of the expected economic damages from carbon dioxide (CO2) emissions. Although useful in an optimal policy context, a world-level approach obscures the heterogeneous geography of climate damage and vast differences in country-level contributions to the global SCC, as well as climate and...
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The distribution of anthropogenic aerosols' climate effects depends on the geographic distribution of the aerosols themselves. Yet many scientific and policy discussions ignore the role of emission location when evaluating aerosols' climate impacts. Here, we present new climate model results demonstrating divergent climate responses to a fixed amou...
Article
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Arctic amplification is a consequence of surface albedo, cloud, and temperature feedbacks, as well as poleward oceanic and atmospheric heat transport. However, the relative impact of changes in sea surface temperature (SST) patterns and ocean heat flux sourced from different regions on Arctic temperatures are not well constrained. We modify ocean-t...
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Ocean acidification threatens many marine organisms, especially marine calcifiers. The only global‐scale solution to ocean acidification remains rapid reduction in CO2 emissions. Nevertheless, interest in localized mitigation strategies has grown rapidly because of the recognized threat ocean acidification imposes on natural communities, including...
Article
Full-text available
Aerosol-cloud-radiative effects are determined and quantified in simulations of deep open-cell stratocumuli observed during the VOCALS-REx campaign off the West coast of Chile. The cloud deck forms in a 1.5km deep boundary layer with cell sizes reaching 50km in diameter. Global data bases of ship tracks suggest that these linear structures are seld...
Article
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Some energy services and industrial processes—such as long-distance freight transport, air travel, highly reliable electricity, and steel and cement manufacturing—are particularly difficult to provide without adding carbon dioxide (CO2) to the atmosphere. Rapidly growing demand for these services, combined with long lead times for technology develo...