Sentences with phrase «global methane concentrations»

Times of war and plague when large population losses could have reduced anthropogenic emissions are coincident with short periods of decreasing global methane concentrations.»

If global levels of hydroxyl decrease, global methane concentrations will increase — even if methane emissions remain constant, the researchers say.

Not exact matches

... A number of scientific studies indicate that most global warming in recent decades is due to the great concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxides and others) released mainly as a result of human activity... Doomsday predictions can no longer be met with irony or disdain.

He also models the global warming that would occur if concentrations of greenhouse gases in the atmosphere were to be doubled (due to increases in carbon dioxide and methane emissions from dragons and the excessive use of wildfire).

To get a global look at methane concentrations before, during, and after the plateau, the team amassed atmospheric methane concentration data from measuring stations from Canada to China to Australia, spanning a period from 1984 through 2015.

During the early 2000s, environmental scientists studying methane emissions noticed something unexpected: the global concentrations of atmospheric methane (CH4)-- which had increased for decades, driven by methane emissions from fossil fuels and agriculture — inexplicably leveled off.

Mapping methane plumes on the streets of Boston and San Francisco paints a picture of «clean» streets with few natural gas leaks, and more common «dirty» streets where methane concentrations can be more than 15 times global background levels.

«It is true that there are other factors (such as volcanism, the changes in the orbit and the axis of the Earth, the solar cycle), but numerous scientific studies indicate that most of the global warming in recent decades is due to the large concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxide and others) mainly emitted due to human activity.»

If this is correct, then we could be seeing be a very limited negative feedback from global warming just now which increases hydroxyl concentrations which in turn breaks down the methane faster.

If Arctic methane were driving a substantial increase in the global atmospheric methane concentration, it would be detectable in this time - mean interhemispheric gradient.

Shakhova et al (2013) show shipboard measurements of methane concentrations in the air above the ESAS that are almost twice as high as the global average (which is already twice as high as preindustrial).

Certainly high methane concentrations indicate emission fluxes, but it's not straightforward to know how significant that flux is in the global budget.

AC at 78 wrote: «If there are bubbles of methane here and there boosting the local CH4 concentration spectacularly but which on the global level amount to less than 3 % of the effect of CO2 emissions from fossil fuels, what does it matter really?»

If there are bubbles of methane here and there boosting the local CH4 concentration spectacularly but which on the global level amount to less than 3 % of the effect of CO2 emissions from fossil fuels, what does it matter really?

For example, Isaken et al (2011) quantify how as atmospheric methane concentrations increase, the global warming potential, GWP, of methane also increases (see references at end of post).

Lawrence Cathles at Cornell said he had confidence that more observation, from direct measurements to global tracking of methane concentrations, would allow gas development to proceed while limiting climate impacts.

«the European Project for Ice Coring in Antarctica (EPICA) established a precise link between climate records from Greenland and Antarctica using data on global changes in methane concentrations derived from trapped air bubbles in the ice.»

We find that the global methane hydrate inventory decreases by approximately 70 % (35 %) under four times (twice) the atmospheric CO2 concentration and is accompanied by significant global oxygen depletion on a timescale of thousands of years.

It is true that there are other factors (such as volcanism, the changes in the orbit and the axis of the Earth, the solar cycle), but numerous scientific studies indicate that most of the global warming in recent decades it is due to the large concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxide and others) mainly emitted due to human activity.

Re inline response in # 6 Then there is a problem with our global methane monitoring system because it shows higher concentrations of methane in north.

The mighty global increase of methane concentration in the air that haunted humanity in the 20th century has been reduced to almost nothing since 2000.

«Long - Term Decline of Global Atmospheric Ethane Concentrations and Implications for Methane.»

Increasing concentrations of greenhouse gases such as carbon dioxide and methane increase the temperature of the lower atmosphere by restricting the outward passage of emitted radiation, resulting in «global warming,» or, more broadly, global climate change.»

Although this concentration is far less than that of CO2, methane is 30 times as potent a greenhouse gas and so may now be responsible for 15 — 20 % of the predicted global warming.»

Why are the global atmospheric concentrations of methane leveling off?

Also, while we have good atmospheric measurements of other key greenhouse gases such as carbon dioxide and methane, we have poor measurements of global water vapor, so it is not certain by how much atmospheric concentrations have risen in recent decades or centuries, though satellite measurements, combined with balloon data and some in - situ ground measurements indicate generally positive trends in global water vapor.»

Methane emissions rising, could worsen global warming Methane emissions rising, could worsen global warming mongabay.com September 27, 2006 Concentrations of methane, a greenhouse gas more than twenty times more poMethane emissions rising, could worsen global warming Methane emissions rising, could worsen global warming mongabay.com September 27, 2006 Concentrations of methane, a greenhouse gas more than twenty times more poMethane emissions rising, could worsen global warming mongabay.com September 27, 2006 Concentrations of methane, a greenhouse gas more than twenty times more pomethane, a greenhouse gas more than twenty times more potent...

The term global warming is now popularly used to refer to the recent reported increase in the mean surface temperature of the earth; this increase being attributed to increasing human activity and in particular to the increased concentration of greenhouse gases (carbon dioxide, methane and nitrous oxide) in the atmosphere.

«Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice cores spanning many thousands of years.»

Higher methane concentrations in the atmosphere will accelerate global warming and hasten local changes in the Arctic, speeding up sea - ice retreat, reducing the reflection of solar energy and accelerating the melting of the Greenland ice sheet.

It's said by suspected fossil fuel lobbyists and the idiots Trump has appointed to oversee environmental agencies that «scientists don't agree» over global warming, actually the problem is that the results don't agree, inasmuch as the graphs tend to be polynomial — also it's quite difficult to measure methane concentrations, it appears, as they vary considerably according to altitude.

The areal extent of methane - rich sediments is fairly well known from seismic observations of this feature, but uncertainty in the concentration of methane in those sediments is very large, thus resulting in the large uncertainty in the global inventory of ocean - floor methane.

«Ship - based observations show that methane concentrations in the air above the East Siberian Sea Shelf are nearly twice as high as the global average... Layers of sediment below the permafrost slowly emit methane gas, and this gas has been trapped for millennia beneath the permafrost.

RealClimate is wonderful, and an excellent source of reliable information.As I've said before, methane is an extremely dangerous component to global warming.Comment # 20 is correct.There is a sharp melting point to frozen methane.A huge increase in the release of methane could happen within the next 50 years.At what point in the Earth's temperature rise and the rise of co2 would a huge methane melt occur?No one has answered that definitive issue.If I ask you all at what point would huge amounts of extra methane start melting, i.e at what temperature rise of the ocean near the Artic methane ice deposits would the methane melt, or at what point in the rise of co2 concentrations in the atmosphere would the methane melt, I believe that no one could currently tell me the actual answer as to where the sharp melting point exists.Of course, once that tipping point has been reached, and billions of tons of methane outgass from what had been locked stores of methane, locked away for an eternity, it is exactly the same as the burning of stored fossil fuels which have been stored for an eternity as well.And even though methane does not have as long a life as co2, while it is around in the air it can cause other tipping points, i.e. permafrost melting, to arrive much sooner.I will reiterate what I've said before on this and other sites.Methane is a hugely underreported, underestimated risk.How about RealClimate attempts to model exactly what would happen to other tipping points, such as the melting permafrost, if indeed a huge increase in the melting of the methal hydrate ice WERE to occur within the next 50 years.My amateur guess is that the huge, albeit temporary, increase in methane over even three or four decades might push other relevent tipping points to arrive much, much, sooner than they normally would, thereby vastly incresing negative feedback mechanisms.We KNOW that quick, huge, changes occured in the Earth's climate in the past.See other relevent posts in the past from Realclimate.Climate often does not change slowly, but undergoes huge, quick, changes periodically, due to negative feedbacks accumulating, and tipping the climate to a quick change.Why should the danger from huge potential methane releases be vievwed with any less trepidation?

Increasing reliance on natural gas (methane) to meet global energy demands holds implications for atmospheric CO2 concentrations.

A combination of historical ice core data and air monitoring instruments reveals a consistent trend: global atmospheric methane concentrations have risen sharply in the past 2000 years.

Although projected CO2 concentrations in a «methane economy» are low in relation to other scenarios, the projections confirm that global climate warming is likely to be a major planetary concern throughout the twenty - first century.

The models heavily relied upon by the Intergovernmental Panel on Climate Change (IPCC) had not projected this multidecadal stasis in «global warming»; nor (until trained ex post facto) the fall in TS from 1940 - 1975; nor 50 years» cooling in Antarctica (Doran et al., 2002) and the Arctic (Soon, 2005); nor the absence of ocean warming since 2003 (Lyman et al., 2006; Gouretski & Koltermann, 2007); nor the onset, duration, or intensity of the Madden - Julian intraseasonal oscillation, the Quasi-Biennial Oscillation in the tropical stratosphere, El Nino / La Nina oscillations, the Atlantic Multidecadal Oscillation, or the Pacific Decadal Oscillation that has recently transited from its warming to its cooling phase (oceanic oscillations which, on their own, may account for all of the observed warmings and coolings over the past half - century: Tsoniset al., 2007); nor the magnitude nor duration of multi-century events such as the Mediaeval Warm Period or the Little Ice Age; nor the cessation since 2000 of the previously - observed growth in atmospheric methane concentration (IPCC, 2007); nor the active 2004 hurricane season; nor the inactive subsequent seasons; nor the UK flooding of 2007 (the Met Office had forecast a summer of prolonged droughts only six weeks previously); nor the solar Grand Maximum of the past 70 years, during which the Sun was more active, for longer, than at almost any similar period in the past 11,400 years (Hathaway, 2004; Solankiet al., 2005); nor the consequent surface «global warming» on Mars, Jupiter, Neptune's largest moon, and even distant Pluto; nor the eerily - continuing 2006 solar minimum; nor the consequent, precipitate decline of ~ 0.8 °C in TS from January 2007 to May 2008 that has canceled out almost all of the observed warming of the 20th century.

But at the same time, global concentrations of methane (blue line in the top chart) have risen.

methane concentrations have been increasing in the atmosphere... but NASA do not include it among their 5 indicators of Global Warming (Sea Level, Arctic Sea Ice, Atmospheric CO2 Concentration, Global Surface Temperature, Ozone Hole).