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Global CO2 emissions 'stalled' in 2014

The growth in global carbon emissions stalled last year, according to data from the International Energy Agency.
It marks the first time in 40 years that annual CO2 emissions growth has remained stable, in the absence of a major economic crisis, the agency said.

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First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect at the Earth's Surface

Scientists have observed an increase in carbon dioxide's greenhouse effect at the Earth's surface for the first time. The researchers, led by scientists from the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), measured atmospheric carbon dioxide's increasing capacity to absorb thermal radiation emitted from the Earth's surface over an eleven-year period at two locations in North America. They attributed this upward trend to rising CO2 levels from fossil fuel emissions.
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'Next Pinatubo' a test of geoengineering

Scientists who study ideas to engineer the climate to mitigate global warming say we should be ready to deploy an armada of instrumentation when Earth has its next major volcanic eruption.
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Ancient climate records 'back predictions'

Records of carbon dioxide in the atmosphere millions of years ago support current predictions on climate change, say scientists.
Evidence from the last warm period in the Earth's ancient past suggests the climate will respond as expected to rising CO2 levels.

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Fossil fuels should be 'phased out by 2100' says IPCC

The unrestricted use of fossil fuels must end soon if the world is to avoid dangerous climate change.
That's one of the key messages in a new report from the Intergovernmental Panel on Climate Change.
The IPCC outlines an approach that could see most of the world's electricity produced from low carbon sources by 2050.

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Widespread methane leakage' from ocean floor off US coast

Researchers say they have found more than 500 bubbling methane vents on the seafloor off the US east coast.
The unexpected discovery indicates there are large volumes of the gas contained in a type of sludgy ice called methane hydrate.

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Title: How close is Earth to a runaway greenhouse?
Authors: Ramses M. Ramirez, Ravi kumar Kopparapu, Valerie Lindner, James F. Kasting

Recent calculations suggest that the inner edge of the habitable zone around the Sun could be as far out as 0.99 astronomical units (AU)- much closer to the orbit of Earth than had been thought. This reopens the question of whether future increases in atmospheric CO2 might trigger a runaway or moist greenhouse. A runaway greenhouse implies complete ocean vaporisation; a moist greenhouse implies that the stratosphere becomes wet, leading to ocean loss via hydrogen escape to space. Previous studies (Kasting and Ackerman, 1986) had indicated that neither a moist nor a runaway greenhouse could be triggered by CO2 increases of any magnitude. Here, we revisit this question with a 1-D climate model that includes updated absorption coefficients for CO2 and H2O, along with an improved parameterisation of tropospheric relative humidity. We find that a runaway greenhouse is still precluded. However, a moist greenhouse could conceivably be triggered by an 11-fold increase in atmospheric CO2, and humans could be subject to fatal heat stress for CO2 increases of (4-8)-fold. When this relative humidity parameterisation is used in our habitable zone calculations, the inner edge moves inward to 0.97 AU. Both of these calculations remain overly pessimistic, as relative humidity may increase more slowly than assumed and cloud feedback is probably negative in this temperature regime. Finally, we reexamine the lifetime of the biosphere against solar luminosity increases and show that older calculations suggesting ~0.5 Ga and 0.9 Ga as the lifetime for C3 and C4 photosynthesis are still approximately correct. Improvements in all of these estimates could be made with a properly formulated 3-D climate model that can self-consistently calculate relative humidity and cloud feedbacks.

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NASA Ozone Study May Benefit Air Standards, Climate

A new NASA-led study finds that when it comes to combating global warming caused by emissions of ozone-forming chemicals, location matters.
Ozone is both a major air pollutant with known adverse health effects and a greenhouse gas that traps heat from escaping Earth's atmosphere. Scientists and policy analysts are interested in learning how curbing the emissions of these chemicals can improve human health and also help mitigate climate change.

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NRL Scientists Detect Carbon Dioxide Accumulation at the Edge of Space

A team of scientists from the Naval Research Laboratory, Old Dominion University, and the University of Waterloo reports the first direct evidence that emissions of carbon dioxide (CO2) caused by human activity are propagating upward to the highest regions of the atmosphere. The observed CO2 increase is expected to gradually result in a cooler, more contracted upper atmosphere and a consequent reduction in the atmospheric drag experienced by satellites. The team published its findings in Nature Geoscience on November 11, 2012 (10.1038/NGEO1626).
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Sky-high methane mystery closer to being solved, UCI researchers say

Commercial natural gas was likely major factor in late-20th century stabilisation

Increased capture of natural gas from oil fields probably accounts for up to 70 percent of the dramatic levelling off seen in atmospheric methane at the end of the 20th century, according to new UC Irvine research being published Thursday, Aug. 23, in the journal Nature.
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