Sentences with phrase «when atmospheric levels»

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...

Not exact matches

This draft can be quickly increased if a low level jet stream exists over or near the fire, or when an atmospheric temperature inversion cap is pierced by it.

In the samples studied by the scientists, there are also high levels of atmospheric contamination from lead during the Roman Empire, when large quantities of this metal were extracted in the south of the Iberian Peninsula, as well as during the past 300 years, coinciding with the Industrial Revolution and the reactivation of mining activity in southern Spain.

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.

Scientists can determine ancient atmospheric concentrations by measuring CO2 and methane levels in tiny air bubbles trapped in such ice, formed when the ice fell to the earth as snow.

When the researchers placed the material inside a gas chamber and cranked up the air pressure from one bar (about the atmospheric pressure at sea level) to five bars, the cube's volume increased by about 3 percent.

«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.

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.

Turning up the heat seems to increase the rate at which the plants produce methane, Keppler says, which could explain why atmospheric levels of methane were high hundreds of thousands of years ago when global temperatures were balmy.

This dynamic time for East Antarctic glaciers occurred when atmospheric temperatures and atmospheric CO2 levels were similar to or higher than present day.

«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.

When they factored in a constant level of CO2, they discovered a surprising development: The change required a lower overall atmospheric pressure — about one - sixth today's pressure at sea level.

Two billion years ago, around the time atmospheric oxygen levels were rising, one cell engulfed another, and instead of becoming lunch, the ingestee became an Earth - changer and, eventually, a vital part of you: mitochondria.These microscopic cell inhabitants / engines allowed their host cell to suddenly begin to burn oxygen when digesting their food, an energy source that vastly expanded the amount of energy they could harvest from a given morsel of food.

A 2008 study led by James Hansen found that climate sensitivity to «fast feedback processes» is 3 °C, but when accounting for longer - term feedbacks (such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra or ocean), if atmospheric CO2 remains at the doubled level, the sensitivity increases to 6 °C based on paleoclimatic (historical climate) data.

Someone please tell me the relevance anymore of man's continued contribution to atmospheric CO2 levels, when enough momentum has already been unleashed to begin the thaw of the permafrost region, which of course contains an immense self - feeding mechanism.

When add in a environment like the top of Everest where the atmospheric pressure and inspired oxygen pressure fall roughly... 30 % of the sea level value at 8900 m which is the height of the summit of Everest.

Production values aren't sky - high, but there are atmospheric moments, particularly when it goes dark and you're given a flashlight (I just wish it could be held it in both orientations), and levels have been designed intelligently to play to the strengths of VR.

When snowfall is high in Siberia, the resultant cold air enhances atmospheric disturbances, which propagate into the upper level of the atmosphere, or stratosphere, warming the polar vortex.

Put it this way if atmospheric levels of CO2 were fixed at to - day's level (380ppm) indefinitely when would we see global temperatures 0.5 deg C higher than to - day.

Jim Bullis, Miastrada Co. (391)-- Maybe shouldn't count on oysters, as «Our analysis shows an intense wintertime minimum in CO32 − south of the Antarctic Polar Front and when combined with anthropogenic CO2 uptake is likely to induce aragonite undersaturation when atmospheric CO2 levels reach ≈ 450 ppm.

Their argument is that tropical Cumulonimbus (thunderstorm) clouds procuce less high - level cirrus - cloud outflow when sea surface temperatures (SST's) are warmer and atmospheric water vapor is higher.

Transient climate sensitivity: The global mean surface - air temperature achieved when atmospheric CO2 concentrations achieve a doubling over pre-industrial CO2 levels increasing at the assumed rate of one percent per year, compounded.

The Solomon Committee report amplifies this conclusion when it confirms that we observe, in any year, only 50 % of the warming to which we have committed the planet by allowing atmospheric concentrations of greenhouse gases to rise to the then current level.

Low atmospheric CO2 levels during the Permo - Carboniferous...... at a time when total atmospheric pressure was similar or slight higher than now.

And the reason those 21st century emissions fail to make much of an impression on global temperature is because the atmospheric levels of GHG begin to decline when our emissions are cut (the cut required depending on the gas in question).

«This perspective article focuses on intervals in time in the fossil record when atmospheric CO2 concentrations increased up to 1200 ppmv, temperatures in mid - to high - latitudes increased by greater than 4 °C within 60 years, and sea levels rose by up to 3 m higher than present.

[Response: That is a positive feedback that acted during ice age cycles: when it got warmer at the end of an ice age, this led to release of stored CO2 from the deep ocean, thus raising atmospheric CO2 levels.

However, when heated to temperatures of over 705 °F and pressures of more than 3200 pounds per square inch (psi; atmospheric pressure is about 15 psi at sea level), water enters a unique, supercritical phase.

On another subject, now that we know from Al Gore's researches, that our SUVs, which keep raising the CO2 levels at Mauna Loa, are the direct cause of the Mediaeval Warm Period (remember that was just 800 years before the present rising CO2 event); we can predict with near certainty, that when everybody who signed on to the Kyoto accords, meets their obligations, resulting in a coming dearth of atmospheric CO2, that is going to directly cause an event which will become known as the little ice age which happened in the 1600 to 1840 time range.

But the evidence shows this can't be true; temperature changes before CO2 in every record of any duration for any time period; CO2 variability does not correlate with temperature at any point in the last 600 million years; atmospheric CO2 levels are currently at the lowest level in that period; in the 20th century most warming occurred before 1940 when human production of CO2 was very small; human production of CO2 increased the most after 1940 but global temperatures declined to 1985; from 2000 global temperatures declined while CO2 levels increased; and any reduction in CO2 threatens plant life, oxygen production, and therefore all life on the planet.

Laboratory evidence suggests that the effectiveness of photosynthesising organisms is badly hindered when CO2 levels drop below about 200ppm (and indeed commercial greenhouses pump in extra CO2 to improve the efficiency of some plant growth — my non-researched background is that tomato plants particularly respond well to this), but the geological evidence suggests that life can tolerate far higher atmospheric CO2 levels.

We present a large - scale Southern Ocean observational analysis that examines the seasonal magnitude and variability CO32 − and pH. Our analysis shows an intense wintertime minimum in CO32 − south of the Antarctic Polar Front and when combined with anthropogenic CO2 uptake is likely to induce aragonite undersaturation when atmospheric CO2 levels reach ≈ 450 ppm.»

Do you recall when climate «experts» told us it's was all about physics... that increasing CO2 atmospheric CO2 levels would absolutely produce perilous, breakneck accelerating climate temps... they said it was all «consensus» science and, btw, it's the physics, stupid... ooops, those pesky and stubborn facts strike again...

During times of warmth, the ocean water levels rise as atmospheric moisture increases but at a rate decelerating when atmospheric temperatures over oceans approach say 33 C.

Most corals evolved in the Ordovician when the atmospheric CO2 was at least 10 times the current levels.

Given evolution over the past 500 million years when virtually all modern emerged and radiated largely occurred while the planet had no polar ice caps and atmospheric CO2 up to ten times current level, and the planet was green from pole to pole, and life did so well it was able to sequester huge amounts of energy in fossil fuel beds.

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).

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.

The dilemma is this: the rate of increase of atmospheric CO2 has leveled off at around 0.5 % per year, over a time period when human population was growing at 1.7 % per year.

If we assume (as IPCC does) that human CO2 emissions are the single cause of increased atmospheric CO2 concentrations, the we could asymptotically reach an absolute highest level of atmospheric CO2 of around 1,030 ppmv WHEN ALL FOSSIL FUELS ARE 100 % USED UP.

This is apparent when comparing atmospheric CO2 levels to volcanic activity since 1960.

To illustrate the implications, Weitzman notes that, when we run the climate models, a normal («thin - tailed») distribution of impacts from a doubling of atmospheric greenhouse gas concentrations above pre-industrial levels produces a median temperature change of 3 degrees Celsius with a 15 % probability of a warming above 4.5 degrees Celsius.

This vast emission has spiked atmospheric CO2 and CO2e (when all other heat trapping gasses are included) levels to above 400 parts per million and 481 parts per million respectively.

If we continue emitting large amounts of CO2 while we work towards converting to 3/4 solar power and survive the heating that we inadvertently speed up by reflecting more heat into an atmosphere already overburdened with reflective - heat - capturing CO2, some day in the future when the atmospheric CO2 returns to its natural percentage of 0.0300 % instead of today's extremely high 0.03811 % the world will cool down to the levels that nature intended.

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?).

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.

One explanation for the seasonal offset is that the large summertime snow / ice change alters ground temperatures, and these ground temperature changes are felt more at ground - level during winter when the surface atmospheric layer is most stable.

The natural acceleration of the the hydrological cycle that occurs when CO2 levels rise, increases rock weathering and is the key to the negative feedback that eventually pulls the atmospheric CO2 levels back down.