Sentences with phrase «since ice core records»

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).

Not exact matches

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 (bRecord 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 (brecord since at least 1550 CE (black).

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.

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.

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.

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.

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.

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.

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).

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.

What's more, scientists have detailed records of past CO2 levels from ice core studies, which show that CO2 levels are higher today than at any point since our distant ancestors began migrating out of Africa 800,000 years ago.

By comparing the atmospheric CO2 increase (note that since CO2 is well - mixed in the atmosphere, a single ice core record can be used as an accurate representation for CO2 - Shakun et al. used the Antarctic EPICA Dome C ice core for CO2 data) to these many different temperature records, Shakun et al. are able to discern whether the CO2 increase led or lagged temperature changes in various different geographic locations, and for the planet as a whole.

CO2 Concentrations: record of global CO2 concentration for the last 1000 years, derived from measurements of CO2 concentration in air bubbles in the layered ice cores drilled in Antarctica (blue line) and from atmospheric measurements since 1957.