Sentences with phrase «when atmospheric carbon»

Ancient pollen samples suggest that the landscape was a bit like today's Chilean Andes: grassy tundra dotted with small trees.This vegetated period peaked during the middle Miocene, when atmospheric carbon dioxide levels were around 400 to 600 parts per million.

When atmospheric carbon dioxide is absorbed into the ocean, it reacts to produce carbonic acid, increasing the acidity of seawater and diminishing the amount of a key building block (carbonate) used by marine species like shellfish and corals to make their shells and skeletons.

It is tough to stay positive when atmospheric carbon levels seem to be rising with no end in sight.

«Wheat's photosynthetic pathway evolved 100 million years ago when atmospheric carbon dioxide levels were up to 10 times higher than they are today,» he said.

Not exact matches

When active, biocrusts take up atmospheric carbon dioxide and fix nitrogen, contributing to the ecosystem's primary productivity.

Franck Montmessin of the LATMOS atmospheric research centre in France says ozone forms when sunlight breaks up carbon dioxide molecules on the planet's daylight side.

What happens when the world moves into a warm, interglacial period isn't certain, but in 2009, a paper published in Science by researchers found that upwelling in the Southern Ocean increased as the last ice age waned, correlated to a rapid rise in atmospheric carbon dioxide.

Black carbon aerosols — particles of carbon that rise into the atmosphere when biomass, agricultural waste, and fossil fuels are burned in an incomplete way — are important for understanding climate change, as they absorb sunlight, leading to higher atmospheric temperatures, and can also coat Arctic snow with a darker layer, reducing its reflectivity and leading to increased melting.

Carbon burial is an important metric when it comes to predicting future atmospheric carbon dioxide levels because, once carbon is in the sediments, it has the potential to remain there and not contribute to the greenhouse effect.

Since 1956, when the monitoring of atmospheric CO2 concentrations began at Mauna Loa Observatory (MLO), many more stations have been added to measure the amount of carbon in the atmosphere and how it varies seasonally and geographically.

Most of the time, atmospheric chemists can see the carbon clumping taking place; when the microscopic bits reach a certain size, they are able to attract and hold water.

When it comes to climate change science, researchers typically use atmospheric carbon dioxide levels from the late 19th century as a guideline, because that's when instrumentation was developed to accurately measure temperatuWhen it comes to climate change science, researchers typically use atmospheric carbon dioxide levels from the late 19th century as a guideline, because that's when instrumentation was developed to accurately measure temperatuwhen instrumentation was developed to accurately measure temperatures.

«Modern atmospheric carbon dioxide levels are today equivalent to those about three million years ago, when sea level was at least six meters higher because the ice sheets were greatly reduced.

Although scientists have measured atmospheric CO2 levels for decades, the current network of ground stations, observatories, aircraft and other instruments emerged during an era when researchers were trying to answer questions about the total amount of carbon dioxide in the atmosphere.

Initial SAM results show an increase of 5 percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed.

Although carbon monoxide is a gas that can be fatal when inhaled, the meat industry insists that it is not harmful to human health when ingested via atmospheric packaging, which utilizes carbon monoxide gas to extend the shelf life and resist spoilage.

The combination of observation - based estimates... with NCAR CSM1.4 - carbon model projection indicates that 10 % of the surface water along the investigated Arctic transect will become undersaturated for at least one month of the year when atmospheric CO2 exceeds 409 ppm.

The trouble is that there remains little empirical evidence to support the idea, as we were surprised to find out when we talked to UC San Diego atmospheric physicist Veerabhadran Ramanathan about his research showing that another type of aerosol — black carbon — had a significant warming effect:

Glacial periods give way to interglacials on some occasions when the Northern Hemisphere's summer solar insolation (the amount of solar radiation received by Earth's surface) increases alongside corresponding decreases in ice volume and increases in temperature and atmospheric carbon dioxide (CO2).

And as to his claim that there may be «places around the world where global warming will lead to less crop success and yield, even when taking into account the carbon dioxide fertilization effect,» he appears to be equally ignorant that rising levels of atmospheric CO2 tend to raise the temperature of optimum plant photosynthesis beyond the predicted temperature values associated with global warming, effectively nullifying this worn out claim (Idso & Idso, 2011).

Making ethanol from corn reduces atmospheric releases of the greenhouse gas carbon dioxide because the CO2 emitted when the ethanol burns is «canceled out» by the carbon dioxide taken in by the next crop of growing plants, which use it in photosynthesis.

The devotees of both sides of the mainstream climate debate i.e. on the one hand those who warn against the dangers of global warming, which they attribute mainly to atmospheric emissions of carbon dioxide, and on the other those who assert that the theory of anthropogenic global warming is a fraud, resort to hysteria when they sense that their ideas are under threat.

A «carbon neutral» bioenergy source would be one that sequestered as much carbon in its growth cycle as it released later when burned as fuel, with the sequestering occurring concurrently with the burning, or nearly so, rather than decades hence, when the negative emissions count for less in stabilizing atmospheric CO2 levels.

When we talk about climate change, we're talking about the scientifically observable — and increasingly severe — changes in global climate patterns that became apparent in the mid-to-late twentieth century and can be attributed to the rising levels of atmospheric greenhouse gases (carbon dioxide, in particular) produced by human activities like burning fossil fuels.

When Arrhenius came out with his theory in 1896 he calculated that doubling atmospheric carbon dioxide will raise global temperature by four - five degrees.

The Keeling Curve, a daily record of atmospheric carbon dioxide, has been running continuously since March 1958, when a carbon dioxide monitor was installed at Mauna Loa in Hawaii.

Since 1850, about the time the Industrial Revolution really got underway and when people started seriously trying to monitor and record local temperatures, atmospheric carbon dioxide has risen from about 285 parts per million (ppmv) 1 to about 380 ppmv today2.

One can even imagine a time in the future when the fee will begin to decrease to some low price as atmospheric carbon dioxide levels return to a value believed to be sustainable (say 300 ppm?).

Conversely, standing forests absorb almost 15 percent of atmospheric carbon, creating a double whammy for the climate when forests are destroyed.

Global atmospheric carbon dioxide concentrations have now passed 400 parts per million (ppm), a level that last occurred about 3 million years ago, when both global average temperature and sea level were significantly higher than today.

Using a crop model they compared how well spring wheat in China and groundnuts in West Africa would grow under these scenarios when compared to a third «control» scenario that holds atmospheric carbon dioxide at 440ppm.

The problem is that atmospheric carbon is a finite resource and when you can build stuff for free with it people will quickly start reducing it to dangerously low levels.

This occurs when additional nutrients promote atmospheric carbon sequestration via enhanced photosynthesis leading to accelerated rates of organic carbon sedimentation and burial.

No Heywood, the cycle is the carbon (the element) cycle and when talking about the carbon cycle it is not incorrect to talk about where the carbon is located: whether that be dissolved in water, as part of a large carbon based life form or in a gaseous atmospheric compound.

When NASAâ $ ™ s James Hansen sounded the alarm in Congress 20 years ago, he predicted that rising concentrations of atmospheric carbon dioxide, or CO2, would drive global temperatures higher by 0.34 degrees Celsius during the 1990s.

According to him, what happens is that when more carbon dioxide is added to the atmosphere it begins to absorb immediately and atmospheric transmittance drops below that optimal 15 percent.

Nothing, right... except when you consider that the radiative forcing due to doubling of the atmospheric concentration of carbon dioxide is only about 3.7 W / m ², and that's expected to change the average surface temperature by about 3 °C, eventually ³.

When we burn fossil fuels, we withdraw carbon from the long - term banking account, then spew it out our smokestacks, depositing it in the short - term cycle, in the form of atmospheric CO2.

Jim had been invited to give a lecture in memory of Charles David Keeling, the legendary greenhouse pioneer who had shown that the atmospheric level of carbon dioxide has been rising steadily since 1958, when he first began monitoring the gas with an instrument on the summit of Hawaii's Mauna Loa volcano.

Obviously when two oxygen atoms are coupled to a carbon atom it now acts as a pseudo-Tachyon; a carbon atom knows when it is going to be oxidized in the future and it knows the future atmospheric temperature equilibrium point, so while not bound to oxygen suck up heat and then store it and then when burnt, wait a few decades, and release the heat they have been storing up while sitting in coal veins or in oil formations.

When those stored molecules eventually return to the surface, pH can be lowered due to respiration of ancient carbon, independent of atmospheric CO2.

When atmospheric CO2 exchanges across the air — sea interface it reacts with seawater through a series of four chemical reactions that increase the concentrations of the carbon species: dissolved carbon dioxide (CO2 (aq)-RRB-, carbonic acid (H2CO3) and bicarbonate (HCO3 ---RRB- Hydrogen ions (H +) are produced by these reactions.

This year, the planet passed a dangerous milestone when atmospheric levels of carbon dioxide exceeded 400 parts per million, prompting the scientific community to advocate renewed vigour in efforts to combat climate change, and the UNFCCC's Executive Secretary to call...

These lamps are supposedly «more powerful than a forest» when it comes to removing atmospheric carbon.

For example, when atmospheric concentrations of carbon dioxide increased in geologic times to a certain unknown threshold, it went into the ocean and combined with positively charged calcium ions to form calcium carbonate — limestone.

There is nothing «controversial» about the carbon cycle and the cause of the recent rise in atmospheric CO2 concentration except the superstitious belief of some people that they «know» all that needs to be known when — in reality — the carbon cycle is unquantified in all its parts, not understood in any of its behaviouers, and there are many possible explanations for the recent rise.

When we burn fossil fuels such as coal, oil and natural gas, we add to the atmospheric concentration of carbon dioxide.

Greenhouse warming is ruled out as a cause because there was no increase of atmospheric carbon dioxide when the warming started.

It may be noted also that some authors and inventories refer to «carbon equivalents» when discussing quantities or atmospheric concentrations of greenhouse gases.

RealClimate gives a good explanation of carbon dioxide equivalents when used in terms of atmospheric concentrations rather than emissions at http://www.realclimate.org/index.php/archives/2007/10/co2-equivalents/.