The ice core record

Lorius, C., Jouzel, J., Raynaud, D. et al. (1990). The ice-core record climate sensitivity and future greenhouse warming. Nature 347,139-145. 

Figures 19-3d-f depict both the recent data from ice cores and the contemporary records of N2O, CH4, and CO2 during the most recent 250 years. These illustrate the profound changes that have occurred since the industrial revolution. Although the exact causes of the increases of N2O and CH4 are not yet fully agreed upon, there is no debate regarding the relationship of the increase of CO2 to the burning of fossil carbon and deforestation. In the case of CH4 and CO2, there is also excellent agreement between the ice-core records and the records from direct sampling of the atmosphere, which began in 1957 for CO2 and in ca. 1973 for CH4.

The aerosol and gaseous lead that has settled onto polar ice eventually becomes buried. Thus, ice cores provide an excellent chronological record of lead inputs as shown in Figure 28.25. Humans began smelting lead ores dates back to at least 5000 BC and can be detected in the ice core record. Lead production increased significantly at the start... 

The ice-core records tell a clear story humans have come of age agriculturally and industrially in the most stable climate regime of the last 110,000 years. However, even this relatively stable period is marked by change... [which is] more characteristic of the Earth s climate than is stasis. 

The past 10 000 years have been an exceptionally stable, high-temperature period. Over most of the ice-core record, temperature switched between two quasi-stationary climate stages. 14 From 20 000 to 80 000 years ago. the warm-climate air temperature was about — 35°C and the cold temperature was near —42°C. Transitions between the two climates required as little as 10-20 years, and each climate persisted between 70 and 5 000 years. 

Cuffey K. M. and Brook E. J. (2000) Ice sheets and the ice-core record of climate change. In Earth System Science from Biogeochemical Cycles to Global Change (eds. M. C. Jacobson, R. J. Charlson, H. Rodhe, and G. Orians). Academic Press, San Diego, chap. 18, pp. 459-497. 

Glacial interglacial changes in moisture sources for Greenland influences on the ice core record of climate. Science 261, 508-511. 

Carbon-cycle responses to Holocene climate change have been hypothesized to explain the atmospheric CO2 and CH4 trends observed in the ice-core record of this period. The early Holocene expansion of terrestrial vegetation and soils in areas that were previously glaciated has been suggested as the cause of the early Holocene decrease in CO2 (Indermuhle et al., 1999). Likewise, the increase in atmospheric CO2 between 8 ka and I ka has been attributed to a release of biospheric carbon caused by a global trend during... 

---