Short-term carbon dioxide peaks are detectable within the eight-hundred-thousand-year ice core record
the verdict
OVERSTATED
true in a weaker form than the claim states
refutedsupported
the weight of evidence
2 sources for · 0 against
Ice core data allows for the analysis of atmospheric variations over the past 800,000 years, but the specific detection of short-term carbon dioxide peaks is not supported by the provided sources.
The narrower version of this claim is missing from this receipt.
A comparative analysis of mutual changes in temperature and aerosol content in the atmosphere was carried out by the data of Antarctic ice cores obtained at the Russian Vostok station and within the framework of the international EPICA project for the past 800,000 years. According to the results of cross-wavelet analysis for the last hundreds of thousands of years, variations in the content of aerosol in the atmosphere, as well as in the content of greenhouse gases CO2 and CH4, are generally lagging relative to temperature changes for the glacial cycles that dominated within the past million years with periods of about 100 thousands years associated with change in the eccentricity of the Earth’s orbit around the Sun. At the same time, for shorter-term glacial cycles, opposite effects appear at certain time intervals with a delay in temperature variations relative to variations in the content of radiatively active components in the atmosphere, including marine and continental (dust) aerosol . In particular, the delay of temperature variations with respect to variations in the content of aerosol in the atmosphere (as well as with respect to variations in the content of methane in the atmosphere) manifests itself for modes associated with the obliquity changes with periods of about 40 thousands years.
These ice cores are samples of polar ice obtained by means of drills that reach thousands of meters into ice sheets or high mountain glaciers. Viewing the ice cores is like traveling backwards through time; the deeper the sample, the earlier the time period. Trapped within the ice are air bubbles and other biological evidence that can reveal temperature and carbon dioxide data. Antarctic ice cores have been collected and analyzed to indirectly estimate the temperature of the Earth over the past 400,000 years (Figure 44.26a). The data represented in Figure 44.27 is an example of such analyses. The 0 °C on this graph refers to the long-term average. Temperatures that are greater than 0 °C exceed Earth’s long-term average temperature. Conversely, temperatures that are less than 0 °C are less than Earth’s average temperature. This figure shows that there have been periodic cycles of increasing and decreasing temperature. Before the late 1800s, the Earth has been as much as 9 °C cooler and about 3 °C warmer. Note that the graph in Figure 44.27b shows that the atmospheric concentration of carbon dioxide has also risen and fallen in periodic cycles.
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