Pushker Kharecha's research while affiliated with Lamont - Doherty Earth Observatory Columbia University and other places

Publications (23)

Article
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Following the March 2011 nuclear power plant accident in Fukushima, Japan, nuclear power production declined sharply in that country as well as Germany. Despite widespread media coverage of CO2 emission increases in the first few years afterward, subsequent energy and emission changes and their implications are not well-studied. Here we analyze ene...
Article
Near-universal recognition of the threat of human-caused global warming, tragically, has not been accompanied by comprehensive quantitative assessment of technological options for mitigating climate change. In this issue of Joule, David W. Keith and co-authors describe a process of capturing CO2 from the air and provide a much-needed empirical cost...
Preprint
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The rapid rise of global temperature that began about 1975 continues at a mean rate of about 0.18 °C/decade, with the current annual temperature exceeding +1.25 °C relative to 1880–1920. Global temperature has just reached a level similar to the mean level in the prior interglacial (Eemian) period, when sea level was several meters higher than...
Article
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Global temperature is a fundamental climate metric highly correlated with sea level, which implies that keeping shorelines near their present location requires keeping global temperature within or close to its preindustrial Holocene range. However, global temperature excluding short-term variability now exceeds +1 °C relative to the 1880–1920 mean...
Article
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We use numerical climate simulations, paleoclimate data, and modern observations to study the effect of growing ice melt from Antarctica and Greenland. Meltwater tends to stabilize the ocean column, inducing amplifying feedbacks that increase subsurface ocean warming and ice shelf melting. Cold meltwater and induced dynamical effects cause ocean su...
Article
Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show th...
Article
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Abstract. There is evidence of ice melt, sea level rise to +5-9 meters, and extreme storms in the prior interglacial period that was less than 1°C warmer than today. Human-made climate forcing is stronger and more rapid than paleo forcings, but much can be learned by combining insights from paleoclimate, climate modeling, and on-going observations....
Article
We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth’s measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today’s young people, f...
Article
Full-text available
We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, f...
Article
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Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback...
Article
Sovacool et al.'s analysis of our paper contains numerous errors, misinterpretations, and dubious assumptions. For instance, we make no presumption in our paper that nuclear power is the only major option to replace fossil fuels -- nor have we in the past, as evidenced by our other peer-reviewed publications. Furthermore, all of our results are bas...
Article
In the aftermath of the March 2011 accident at Japan's Fukushima Daiichi nuclear power plant, the future contribution of nuclear power to the global energy supply has become somewhat uncertain. Because nuclear power is an abundant, low-carbon source of base-load power, on balance it could make a large contribution to mitigation of global climate ch...
Article
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Rahmstorf et al ’s (2012) conclusion that observed climate change is comparable to projections, and in some cases exceeds projections, allows further inferences if we can quantify changing climate forcings and compare those with projections. The largest climate forcing is caused by well-mixed long-lived greenhouse gases. Here we illustrate trends o...
Article
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Global warming due to human-made gases, mainly CO2, is already 0.8{\deg}C and deleterious climate impacts are growing worldwide. More warming is 'in the pipeline' because Earth is out of energy balance, with absorbed solar energy exceeding planetary heat radiation. Maintaining a climate that resembles the Holocene, the world of stable shorelines in...
Article
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Improving observations of ocean heat content show that Earth is absorbing more energy from the sun than it is radiating to space as heat, even during the recent solar minimum. The inferred planetary energy imbalance, 0.59 \pm 0.15 W/m2 during the 6-year period 2005-2010, confirms the dominant role of the human-made greenhouse effect in driving glob...
Article
Full-text available
Global warming due to human-made gases, mainly CO2, is already 0.8{\deg}C and deleterious climate impacts are growing worldwide. More warming is 'in the pipeline' because Earth is out of energy balance, with absorbed solar energy exceeding planetary heat radiation. Maintaining a climate that resembles the Holocene, the world of stable shorelines in...
Article
The global climate problem becomes tractable if CO(2) emissions from coal use are phased out rapidly and emissions from unconventional fossil fuels (e.g., oil shale and tar sands) are prohibited. This paper outlines technology options for phasing out coal emissions in the United States by approximately 2030. We focus on coal for physical and practi...
Article
Full-text available
Paleoclimate data show that climate sensitivity is ~3 deg-C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6 deg-C for doubled CO2 for the range of climate states between glacial conditions and ice-free Antarctica. Decreasing CO2 was the main cause of a cooling trend...
Article
Full-text available
Palaeoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the 'albedo flip' property of ice/water, provides a powerful trigger mechanism. A climate forcing that 'flips' the albedo of a sufficient por...
Article
Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven" and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional...

Citations

... Deforestation, fossil-fuel burning and cement production are the main activities that are promoting the current increase of greenhouse gases in the atmosphere. This scenario can only be reverted through actions that can contribute to the reduction of greenhouse gas emissions [1,2]. The encapsulation of CO 2 in the cement-based materials by the accelerated carbonation of hydrated products present in cementitious matrices can contribute to the reduction of the CO 2 balance in the cement production chain. ...
... En tredje uppskattning av framtida kostnader kommer från företaget Global Thermostat, också de ett företag som utvecklar lågtemperaturprocesser De menade sig kunna fånga in koldioxid för så lite som 100-360 kronor per ton. 229 Global Thermostat svarade aldrig på vår förfrågan. För att ytterligare minska kostnaderna för CCSteknik måste fokus ligga på skalfördelar och teknisk utveckling. ...
... Up to now called "chevrons", the peculiar V-and U-shaped oolitic ridges of Late Pleistocene age exposed on several Bahamian islands have drawn the attention of numerous researchers for almost two decades (Bourgeois and Weiss, 2009;Donovan and Tormey, 2015;Engel et al., 2015;Hansen et al., 2020Hansen et al., , 2016Hansen et al., , 2013Hearty et al., 2015Hearty et al., , 2002Hearty et al., , 1998Hearty and Tormey, 2018aKindler andStrasser, 2002, 2000;Mylroie, 2018aMylroie, , 2018bRovere et al., 2018Rovere et al., , 2017Tormey, 1999;Tormey et al., 2018Tormey et al., , 2016Tormey and Donovan, 2015;Vimpere et al., 2019). However, despite the numerous studies pertaining to these landforms, both their formation mechanism and their climatic significance remain uncertain and controversial. ...
... A similar picture emerged in Japan, which following the same accident took its entire nuclear fleet offline for safety checks and a reappraisal of the country's energy policy. As a result of this, driven primarily by a radiophobic reaction to the accident, Japan's dependence on fossil fuels increased, with an associated rise in emissions of both greenhouse gases and air pollution (Kharecha and Sato, 2019). ...
... To complete steps 2 and 3, the top Russian exports are identified-(1) crude petroleum (USD $123B), (2) refined petroleum (USD $66.2B), (3) petroleum gas (USD $26.3B), and (4) coal briquettes (USD $17.6B) [77]. All of the top exports from Russia are fossil fuels, which is a serious threat to global safety if combusted, resulting in greenhouse gas (GHG) emissions and concomitant climate change [78,79]. Such human-caused global climate destabilization is established with a 95% confidence [80] as are the overwhelmingly detrimental repercussions on the environment as well as human social systems [81]. ...
... The continued dependence on fossil energy sources for economic development is the primary source of increasing GHGs (Hansen et al., 2017). There is emerging agreement in terms of the importance of the bioenergy sector for climate change mitigation (Jackson et al., 2016;Hansen et al., 2017), however, the options and limitations in terms of transforming the energy systems to support both mitigation and adaptation are still contested. ...
... Entities in the macroscopic domain have deep histories of emergence, existence and transformation, as evidenced in the development of the universe over billions of years. The world we perceive is like a record book; this is pertinent for the geology of our planet and even the history of Earth's climate with respect to the climate emergency (Hansen et al., 2016). The relative stability of the classical domain is in turn a requirement for evolutionary processes of emergence of complex systems, self-organisation and ultimately the evolution of living structures, conscious neural networks and the emergence of the social domain. ...
... The composition and quantity of released trace metals depends on the mineral used for OAE or EW. Olivine is currently one of the most widely considered minerals due to its relatively fast weathering rates (Taylor et al., 2016;Oelkers et al., 2018). It contains high amounts of nickel (Ni), which was shown to leach out of olivine very efficiently during chemical weathering (Montserrat et al., 2017;Fuhr et al., 2022). ...
... They routinely experience detrimental conditions including biotic and abiotic stresses in natural fields. The current climate changes including frequent extreme temperatures, strong storms, heavy rainfall, and harsh droughts directly threaten normal vegetable development during the entire period of vegetative and reproductive growth (Driedonks et al., 2016;Hansen et al., 2016;Bhutia et al., 2018). Global warming is one of the main issues related to global climate change and is caused by increases of greenhouse gases such as CO 2 , CH 4 , N 2 O, and hydrofluorocarbons (HFCs) that have been produced by urbanization and industrialization (Bhutia et al., 2018;Zandalinas et al., 2021). ...
... The duty of current generations to preserve the livelihood of future generations has been discussed from the perspective of various disciplines, especially philosophy and economics (Rawls, 1971;Tobin, 1974;Ball, 2001;McCormick, 2009;Hay, 2015). The imbalance of causing and carrying environmental problems between generations (Zabern and Tulloch, 2021) is referred to as intergenerational inequality, as the costs on ecosystems and humans will to a large extent be carried by younger and future generations (Hansen et al., 2013). In political debates, the necessity of viewing the impacts of certain policies from an intergenerational perspective is considered to be crucial in order to provide a sustainable societal and ecological system for the future (Buchanan, 2020). ...