Search

Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified. We estimated the commitment to future emissions and warming represented by existing carbon dioxide--emitting devices. We calculated cumulative future emissions of 496 (282 to 701 in lower- and upperbounding scenarios) gigatonnes of C[O.sub.2] from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3[degrees]C (1.1[degrees] to 1.4[degrees]C) above the pre-industrial era and atmospheric concentrations of C02 less than 430 parts per million. Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, C[O.sub.2]-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives. 10.1126/science.1188566

The evolutionary success of planktic calcifiers during the Phanerozoic stabilized the climate system by introducing a new mechanism that acts to buffer ocean carbonate-ion concentration: the saturation-dependent preservation of carbonate in sea-floor sediments. Before this, buffering was primarily accomplished by adjustment of shallow-water carbonate deposition to balance oceanic inputs from weathering on land. Neoproterozoic ice ages of near-global extent and multimillion-year duration and the formation of distinctive sedimentary (cap) carbonates can thus be understood in terms of the greater sensitivity of the Precambrian carbon cycle to the loss of shallow-water environments and C[O.sup.2]-climate feedback on ice-sheet growth., The growth of continental-scale ice sheets extending to the tropics during the second half of the Neoprotemzoic (1000 to 540 million years ago) (1) is now widely accepted in the [...]

Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (~[10.sup.13] watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development., More than a century ago, Arrhenius put forth the idea that C[O.sub.2] from fossil fuel burning could raise the infrared opacity of the atmosphere enough to warm Earth (1). In [...]

In their article 'Comparative Earth history and Late Permian mass extinction' (1), A. H. Knoll et al. suggest that Late Permian extinctions were caused by the release to the atmosphere [...]

The UN Framework Convention on Climate Change calls for 'stabilization of greenhouse gas concentrations at a level that would prevent dangerous anthropogenic interference with the climate system.' Even if we could determine a 'safe' level of interference in the climate system, the sensitivity of global mean temperature to increasing atmospheric C[O.sub.2] is known perhaps only to a factor of three or less. Here we show how a factor of three uncertainty in climate sensitivity introduces even greater uncertainty in allowable increases in atmospheric C[O.sub.2] concentration and allowable C[O.sub.2] emissions. Nevertheless, unless climate sensitivity is low and acceptable amounts of climate change are high, climate stabilization will require a massive transition to C[O.sub.2] emission-free energy technologies., Climate sensitivity (Δ[T.sub.2X]) is the global mean climatological temperature change resulting from a doubling of atmospheric C[O.sub.2] content. Climate sensitivity is thought, based primarily on models, to lie in the [...]

An ocean-climate model that shows high fluxes of anthropogenic carbon dioxide into the Southern Ocean, but very low storage of anthropogenic carbon there, agrees with observation-based estimates of ocean storage of anthropogenic carbon dioxide. This low simulated storage indicates a subordinate role for deep convection in the present-day Southern Ocean. The primary mechanism transporting anthropogenic carbon out of the Southern Ocean is isopycnal transport. These results imply that if global climate change reduces the density of surface waters in the Southern Ocean, isopycnal surfaces that now outcrop may become isolated from the atmosphere, tending to diminish Southern Ocean carbon uptake., There has been considerable debate (1, 2) about the importance of Southern Ocean uptake of anthropogenic [CO.sub.2]. Several modeling studies (2-6) have indicated a relatively large Southern Ocean sink for [...]

Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified. We estimated the commitment to future emissions and warming represented by existing carbon dioxide-emitting devices. We calculated cumulative future emissions of 496 (282 to 701 in lower- and upper-bounding scenarios) gigatonnes of CO2 from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3°C (1.1° to 1.4°C) above the pre-industrial era and atmospheric concentrations of CO2 less than 430 parts per million. Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, CO2-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives. [ABSTRACT FROM AUTHOR]

The article focuses on the climate event, the Paleocene-Eocene Thermal Maximum (PETM) which occurred 55 million years ago. The convergence of isotopic and sedimentological data suggests that the atmospheric carbon dioxide was the main greenhouse gas driving the PETM. Biological responses to the global warming during the PETM brought changes in the ecology of marine organisms, a mass extinction of benthic foraminifera and a global expansion of subtropical dinoflagellats at the earliest onset of the event.

In this article the authors discuss aspects of the report "Atmospheric Pco2 Perturbations Associated with the Central Atlantic Magmatic Province," by Morgan F. Schaller, James D. Wright, and Dennis V. Kent that appeared in the March 18, 2011 issue of "Science."

The article discusses ocean acidification due to carbon emissions. The author says that emission is done to keep climate from changing significantly, but since it has negative effect on ocean it is being reduced. He states that ocean acidification is the intake of ocean of anthropogenic carbon dioxide that results to reduction of potential hydrogen of seawater. In addition, the process causes harm to several marine organisms like production of coral reefs and formation of shells and skeletons and impregnation of marine species.

The evolutionary success of planktic calcifiers during the Phanerozoic stabilized the climate system by introducing a new mechanism that acts to buffer ocean carbonate-ion concentration: the saturation-dependent preservation of carbonate in sea-floor sediments. Before this, buffering was primarily accomplished by adjustment of shallow-water carbonate deposition to balance oceanic inputs from weathering on land. Neoproterozoic ice ages of near-global extent and multimillion-year duration and the formation of distinctive sedimentary (cap) carbonates can thus be understood in terms of the greater sensitivity of the Precambrian carbon cycle to the loss of shallow-water environments and CO[sup2]-climate feedback on ice-sheet growth. [ABSTRACT FROM AUTHOR]

The article discusses Ocean Iron Fertilization (OIF) as a tool in mitigating the rising atmospheric carbon dioxide. The process involves the stimulation of net phytoplankton growth by releasing iron to certain parts of the surface ocean. OIF has been studied for years by the International Oceanographic Community for the improvement of people's understanding to the role of iron in regulating ocean ecosystems and carbon dynamics. Despite the uncertainty in the efficacy of OIF, private organizations are making plans to conduct larger-scale iron releases to generate carbon offsets.

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 (CO 2 ) to the atmosphere. Rapidly growing demand for these services, combined with long lead times for technology development and long lifetimes of energy infrastructure, make decarbonization of these services both essential and urgent. We examine barriers and opportunities associated with these difficult-to-decarbonize services and processes, including possible technological solutions and research and development priorities. A range of existing technologies could meet future demands for these services and processes without net addition of CO 2 to the atmosphere, but their use may depend on a combination of cost reductions via research and innovation, as well as coordinated deployment and integration of operations across currently discrete energy industries., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The Antarctic Ice Sheet stores water equivalent to 58 m in global sea-level rise. We show in simulations using the Parallel Ice Sheet Model that burning the currently attainable fossil fuel resources is sufficient to eliminate the ice sheet. With cumulative fossil fuel emissions of 10,000 gigatonnes of carbon (GtC), Antarctica is projected to become almost ice-free with an average contribution to sea-level rise exceeding 3 m per century during the first millennium. Consistent with recent observations and simulations, the West Antarctic Ice Sheet becomes unstable with 600 to 800 GtC of additional carbon emissions. Beyond this additional carbon release, the destabilization of ice basins in both West and East Antarctica results in a threshold increase in global sea level. Unabated carbon emissions thus threaten the Antarctic Ice Sheet in its entirety with associated sea-level rise that far exceeds that of all other possible sources.

Schaller et al. (Research Article, 18 March 2011, p. 1404) proposed that carbon dioxide (CO(2)) released by the Central Atlantic Magmatic Province eruptions over periods of about 20,000 years led to substantial increases of up to 2000 parts per million (ppm) in the concentration of atmospheric carbon dioxide (PCO(2)) near the Triassic-Jurassic boundary. Use of an atmosphere-ocean model coupled to a carbon-cycle model predicts PCO(2) increases of less than 400 ppm from magmatic volatiles, with only a small climatic impact.