Sentences with phrase «since ice core»

First, he argues that since ice core records show that temperature generally started changing before CO2 concentrations by several hundred years, CO2 can't be a major cause of warming.

C) However, since the ice core record shows many instances where temperatures reverse and drop while CO2 is still increasing and vice versa, it is evident that there are other (largely unknown) climate drivers that routinely overwhelm whatever effect CO2 has on temperatures (positive feedback included).

Since ice cores are a measure of the water in the ice, what the ice core is actually measuring are the conditions of the oceans that the water originally evaporated from.

[Updated 12/12/07: Added myth # 21, since ice cores show CO2 increasing after temperature increases in the past, it must be occuring this time too.]

Not exact matches

Since the ice sheet would have floated away in the event of a global flood, the ice core is strong evidence that there was no global flood any time in the last 110,000 years.

Growth rates for concentrations of carbon dioxide have been faster in the past 10 years than over any 10 - year period since continuous atmospheric monitoring began in the 1950s, with concentrations now roughly 35 percent above preindustrial levels (which can be determined from air bubbles trapped in ice cores).

The cores reveal that the ice layers became thicker and more frequent beginning in the 1990s, with recent melt levels that are unmatched since at least the year 1550 CE.

Record of melt from two west Greenland ice cores showing that modern melt rates (red) are higher than at any time in the record since at least 1550 CE (black).

And since its surface is icy and it has a penchant for spewing water and ammonia into space, researchers have concluded it probably has a crust of ice, a watery mantle and a core of solid rock.

They range from LANDSAT images of land use in the Chesapeake Basin, to fish catches off California since the 1920s, to 400,000 years of global temperature estimates from antarctic ice cores.

Records of nitric acid and carbon - 14 in ice cores show that we have not had a solar flare bigger than the 1859 «Carrington event» since 1561.

Sampling 7,000 - year - old ice cores as well as snowpack dating from 1969 through the mid-1990s, Barbante's team found that concentrations of the metals had risen almost sevenfold since the mid-1970s, when catalytic converters first came into widespread use.

Since then scientists have been studying samples of the bottom core for clues to what might lie beneath the ice.

Most d18O records — in caves stalagmites, lake sediment or ice cores are usually interpreted this way since most of their signal is from the rain water d18O.

This too supports this hypothesis since the greater difficulty in forming cores without the presence of ice would hamper the formation of large planets.

study published June 25 by the Proceedings of the National Academy of Sciences, the Greenland ice core drifts notably from other records of Northern Hemisphere temperatures during the Younger Dryas, a period beginning nearly 13,000 years ago of cooling so abrupt it's believed to be unmatched since.

Marine sediment cores will reveal records of past glacial - interglacial cycles while lake sediments and peat cores will reveal climate records since the last ice age.

The present ice ages are the most studied and best understood, particularly the last 400,000 years, since this is the period covered by ice cores that record atmospheric composition and proxies for temperature and ice volume.

The point of this post is that the ice core data are entirely consistent with what we already knew (and have known since 1896 A.D. when Arrhenius published his climate sensitivity calculations).

WAIS Divide ice core suggests sustained changes in the atmospheric formation pathways of sulfate and nitrate since the 19th century in the extratropical Southern Hemisphere: Atmospheric Chemistry and Physics, 14, p. 5749 - 5769.

When attempts were made to update the record by redrilling in 1991, it was found that the annual cycle had been wiped out over the top 20 meters of the core by percolation of meltwater from extensive melting of the ice surface since 1976.

It was the early, pioneering ice coring efforts in Greenland in the 1980s and 90s that first revealed the abrupt climate shifts called «Dansgaard - Oeschger events» (or simply DO events), which have fascinated and vexed climatologists ever since.

For one thing, the timing with the industrial revolution is hard to dismiss as a coincidence, especially since it is known that CO2 levels haven't been as high as they are now for at least ~ 1 million years (over which we have very good data from ice cores) and likely for the last 20 million years.

The LGM forcings include other well - mixed GHGs (CH4 and N2O) since they are constrained by ice core records.

Since this is an ice core record that frequency is for the location of Summit only.

The so - called «Keeling Curve» of CO2 concentrations since 1958 looks like a spike against the 800,000 - year ice - core record of this atmospheric trace gas.

In our current paper, we reinforce this proposed re-dating by looking at ice core data published since 2010, from both Greenland (NEEM S1 (Sigl et al., 2013)-RRB- and Antarctica (WDC06A (Sigl et al., 2013), Law Dome (Plummer et al., 2012)-RRB- as well as the Antarctic DML core (Traufetter et al., 2004).

We've all seen how well temperature proxies and CO2 concentrations are correlated in the Antarctic ice cores — this has been known since the early 1990's and has featured in many high - profile discussions of climate change.

Hopefully the ice core workers will reexamine their chronologies to try to falsify our hypothesis, since ultimately it will only be the ice cores that can prove us correct or incorrect, and if we are correct, identify where the offset occurs.

Note that part of the uncertainy in all this is the time uncertainty — from the ice core records, we can pick a rather precise time and look at a rather precise number for greenhouse gas concentrations, but pinning down the magnitude albedo change at exactly the same time (since albedo is not globally uniform, obviously) is impossible.

The point of this post is that the ice core data are entirely consistent with what we already knew (and have known since 1896 A.D. when Arrhenius published his climate sensitivity calculations).

If we do that, the increase in atmospheric CO2 from 320 to 390 parts per million since 1850 is only about half as much (22 %) as the cherry - picking IPCC has told us, based solely on ice - core data....

Mauna Loa has only been in operation since 1959, but Vostok ice core estimates (cited by IPCC) put the CO2 level at around 280 ppmv in 1850.

Ice cores show atmospheric CO2 variations to lag behind atmospheric temperature changes on a century to millenium scale, but modern temperature is expected to lag changes in atmospheric CO2, as the atmospheric temperature increase since about 1975 generally is assumed to be caused by the modern increase in CO2.

Based on the GISP2 ice core proxy record from Greenland it has previously been pointed out that the present period of warming since 1850 to a high degree may be explained by a natural c. 1100 yr periodic temperature variation (Humlum et al., 2011).

Based on the ice core dCO2 / dT relationship, the increase in temperature since the LIA has added not more than 6 ppmv to the atmosphere to reach a new equilibrium.

Meanwhile the people predicting a return to the ice cover that existed since the Holocene maximum according to sea floor sediment cores have no physical process to account for their assertions of returning ice.

««Cores obtained to a depth of 2164 meters in the Antarctic ice sheet at Byrd station have undergone considerable relaxation since they were drilled.

Since 1880 to about 1925 more than 80 data series seleced by me to represent typical yearly averagees (when possible) we have nearly identical CO2 values than the ice cores shows!!!

Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores.

What matters is not the warming rate since the mid-19th century but the fact that ice core data reveal the existence of a quasi-millenarian (natural) oscillation, that well correlates with observed (mean) warming observed since the mid-19th century.

Scientists dig deep into the rock and sand of the sea floor to sample Earth's climate history many millions of years ago, since the oldest ice cores go back only 850,000 years.

Mark A.J. Curran, et al., «Ice Core Evidence for Antarctic Sea Ice Decline Since the 1950s,» Science, vol.

And while temperature should decrease the total amount of carbon in the upper layer of the oceans, we see an increase in carbon (and a decrease in 13C / 12C ratio)- Ice cores, tree carbon and coralline sponges all give small 13C / 12C variations over the Holocene, but all show a steady and ever faster decline since about 1850.

Fred Singer is going around claiming that most «tree rings, ice cores, lake and ocean sediments, stalagmites... haven't shown any warming since 1940».

Geoff Hargreaves has worked at the National Ice Core Laboratory since it opened in 1993, when the collection was moved to larger quarters in Colorado from the University at Buffalo of The State University of New York.

Is it possible that since the earth is constantly spinning that the earth has become a sort of centerfuge and that the CO2 and methane are flung outward towards the ionisphere and have to saturate the lower atmosphere before showing up in the ice cores?

I mention this since some global warming science sites show instrument data superimposed over the ice core data.

For example, we know that if the climate wasn't changing, it would be broken, since the evidence tells us that the climate is in a state of continuous change, moreover; nothing about contemporary change is unusual compared to the paleo record, and this is even true when we compare changes in recent 5 year averages to the changes in multi-century averages recorded in ice cores.

«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.»