Sentences with phrase «ice core data which»

ice core data which show a smaller, and less abrupt decline at the end of the 16th century.

I prefer to think Steve has (finally) motivated the Aussies to release ice core data which should have been released a decade + ago.

This is the common sceptic claim that «the prediction is that CO2 is a major driver is refuted by the ice core data which shows it isn't, therefore, CO2 is not a major driver of climate change»

Not exact matches

The researchers studied temperature measurements over the last 150 years, ice core data from Greenland from the interglacial period 12,000 years ago, for the ice age 120,000 years ago, ice core data from Antarctica, which goes back 800,000 years, as well as data from ocean sediment cores going back 5 million years.

It is much cheaper to test ice cores, which capture years of data in one core, than to do repeated air sampling over time.

The ice core data also shows that CO2 and methane levels have been remarkably stable in Antarctica — varying between 300 ppm and 180 ppm — over that entire period and that shifts in levels of these gases took at least 800 years, compared to the roughly 100 years in which humans have increased atmospheric CO2 levels to their present high.

The paleoclimate data, which included mainly changes in the oxygen isotopes of the calcium carbonate deposits, were then compared to similar records from other caves, ice cores, and sediment records as well as model predictions for water availability in the Middle East and west central Asia today and into the future.

Joanne also discusses using ice core data, which is generally reliable.

Other tree ring data, 10 Be data, orbital satellite data, borehole data, ice coring data, etc. show, for example, the lengthy medieval warming which is practically absent from the hockey stick.

Indeed, Gore could have used the ice core data to make an additional and stronger point, which is that these data provide a nice independent test of climate sensitivity, which gives a result in excellent agreement with results from models.

We know from data that we have caused the CO2 concentration in the atmosphere to rise sharply during the past century: it is now much higher than any time during the past 650,000 years (which is as far back as reliable ice core data exist).

An uncertainty in some ice core results is somehow «translated» into a statement about current CO2 emissions data in the 20th and 21st centuries (which can be measured precisely).

As Richard Alley has shown in a couple of papers, the ice core data of DO events are entirely consistent with stochastic resonance — which is not chaos but arises from a simple threshold process («flicking of a switch») in the presence of noise.

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.

>... there are still ways of discovering the temperatures of past centuries,... tree rings... Core samples from drilling in ice fields... historical reconstruction... coral growth, isotope data from sea floor sediment, and insects, all of which point to a very warm climate in medieval times.

The highly accurate ice core data sets rathr precise dates for three major (and tropical) eruptions for which previous studies by traditional methods of paleogeology gave only poorer approximations.

Which is not surprising, given that the ice core data suggest that this feedback only sets in with a delay of hundreds of years after the warming starts.

The pre-1960 data, which comes from ice core samples, has many more problems.

That is the case for Buch's measurements, except for the trip to Spitsbergen and back which had an enormous variability (even there with the ice core data within the range).

For instance, here's the data for delta - oxygen - 18 from a stack of 57 ocean sediment cores, which is considered an excellent proxy for global ice volume, known as the «LR04 stack» (from Lisiecki, L.E., & Raymo, M.E. 2005.

fhhaynie For the empirical ice core and proxy temperature data on which the 1000 year cycle is based see Figs 6 and 7 in the latest post at http://climatesense-norpag.blogspot.com Interestingly Fig 6 also suggests that if you believe (which I obviously don't) that CO2 is the main climate driver - its long term effect is to cool the earth.

exactly... i recall seeing a graph produced from ice core samples in which the CO2 content of thousands of years past was measured against tree ring data... what it showed was CO2 levels rising 300 years after rapid vegetative growth (natural warming) and incidently the PPM of CO2 measured higher than current levels.

This work is the first to consistently recreate the event by computer modeling, and the first time that the model results have been confirmed by comparison to the climate record, which includes such things as ice core and tree ring data.

This is only suggested by ice - core paleoclimate data which is ultimately uncheckable by direct empirical observation.

And this is a crucial point; Salby's conclusions are based on the best measurements; his critics are rabbiting on about ice core data and other proxies which are up there with how's your mother in terms of evidence.

The 1942 «peak» is nowhere seen in any other direct measurement (high resolution ice cores from Law Dome) neither in stomata data for the past century, neither in coralline sponges, the latter based on 13C / 12C ratio's which certainly should change if there was an important change in inputs or outputs from vegetation or oceans.

These have been observed in the paleo record including ice core data plus many historical references, so are very likely to be real (unlike unicorns, which have only been sighted after a night of heavy drinking).

A longer time scale AMO component of 45 — 65 years, which has been seen clearly in the 20th century SST data, is detected only in central Greenland ice cores.

«They're talking about the instrumental data which is unaltered — but they're talking about proxy data going further back in time, a thousand years, and it's just about how you add on the last few years, because when you get proxy data you sample things like tree rings and ice cores, and they don't always have the last few years.

This is the time - span over which temperatures with annual resolution can be calculated using hemispheric - wide tree - ring, ice - cores, corals, and other annually - resolved proxy data.

For the South Pole Ice Core project, in which scientists drilled a core from 2014 to 2016 and continue the research today, Casey and her NASA colleagues helped analyze satellite, airborne and field data to select a place to drill the ice coIce Core project, in which scientists drilled a core from 2014 to 2016 and continue the research today, Casey and her NASA colleagues helped analyze satellite, airborne and field data to select a place to drill the ice cCore project, in which scientists drilled a core from 2014 to 2016 and continue the research today, Casey and her NASA colleagues helped analyze satellite, airborne and field data to select a place to drill the ice ccore from 2014 to 2016 and continue the research today, Casey and her NASA colleagues helped analyze satellite, airborne and field data to select a place to drill the ice coice corecore.

An important point, which we have discussed elsewhere on attribution of CO2 in the Ice Cores, when comparing data looking for signals, is that we are making reasonable assumptions about what we would expect to see before we looking at the data.

Atmospheric CO2, CH4 and N2O have varied almost synchronously with global temperature during the past 800000 years for which precise data are available from ice cores, the GHGs providing an amplifying feedback that magnifies the climate change instigated by orbit perturbations [29 — 31].

Then we use available long - term proxies of the solar activity, which are 10Be isotope concentrations in ice cores and 22 - year smoothed neutron monitor data, to interpolate between the present quiet Sun and the minimum state of the quiet Sun.

Climate change doubters used this analysis to support their belief that — despite climatological data which includes 800,000 year ice - core records of atmospheric carbon dioxide — humans have not affected the atmosphere by releasing billions of tons of carbon dioxide per year.

Also, some proxies show here that the last 3 million years, p.CO2 often could be similar — or higher — than the present (also in the period in which we have data from ice cores).

So, there is a conflict with the ice core data, which says that CO2 has been well behaved.

Stomata data are in no way «better» than ice core CO2 data, they are proxy's of local CO2 levels, not like ice cores which are direct measurements of CO2 in the ancient bulk (95 %) of the atmosphere, be it averaged over several years to several centuries, depending of the snow accumulation rate of the ice core.

If you want data from approximately the same location, just compare the four ice core records shown, which are all from Antarctica, with the South Pole data.

This curve is statistically speaking a «random walk», with no robust statistical correlation with atmospheric CO2, which has seen no cycles but has increased at a fairly constant CAGR of around 0.4 % per year since measurements started at Mauna Loa in 1958 and at an estimated somewhat slower rate before this, based on ice core data.

The issue, beyond the core data representing but a single geospacial location and thus by itself not representative of the whole (and much larger) region in which it resides, is that the core is near the Greenland summit (in order to get the deepest profile of the ice possible) and therefore at an elevation of over 2 miles above sea level.

In this link https://bravenewclimate.com/2016/09/10/open-thread-26/#comment-470348 I briefly outline the results of an important paper which uses Liang causality, a statistical notion superior to the older Granger causality, to analyze the climate data, both ice core and recent, to obtain the expected result that CO2 Liang causes global warming in recent times but the opposite conclusion for the paleodata.

To make it clear: nobody ever has «but» the ice core data and atmospheric data together, without counting the layers for ice (which is the age at closing depth) and the CO2 level changes in firn (which give a nice trend from atmospheric to closing depth).

Therefore we have no later ice core data, but we have firn data, which show a further increase of CO2 until current levels.

Yet the article presents charts based on ice - core data, which show a 1000 - year lag, with CO2 lagging temperature.

IPCC has been myopically fixating on the recent «blip» in our climate (measured since 1850, but with emphasis starting around 1976), trying to tie it to another «blip» in atmospheric CO2 (measured since 1958, with some somewhat questionable ice core data before 1958), which IPCC is assuming has come from anthropogenic sources.