Giving Compass' Take:
- This article analyzes the scientific predictions of sea ice expansion and extended summers as a result of climate change.
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According to the most recent report by the Intergovernmental Panel on Climate Change (IPCC), CO2-induced global warming will result in a considerable reduction in sea ice extent in the Southern Hemisphere.
Specifically, the report predicts a multi-model average decrease of between 16 and 67 percent in the summer and 8 to 30 percent in the winter by the end of the century (IPCC, 2013). Given the fact that atmospheric CO2 concentrations have increased by 20 percent over the past four decades, evidence of sea ice decline should be evident in the observational data if such model predictions are correct. But are they?
The six scientists report the existence of a long-term increasing trend in both sea ice extent and area over the period of study (see figure below), with the former measure increasing by 1.7 percent per decade and the latter by 2.5 percent per decade. They compared satellite-based estimates of temperature over the ocean/ice and found a very high negative correlation between ice cover and temperature. So, the large and systematic increase in ice extent must be related to a cooling over the sea-ice region throughout the 36-year period of record in this study.
Consequently, it is clear that despite a 20 percent increase in atmospheric CO2, and model predictions to the contrary, sea ice in the Antarctic has expanded for decades. Such observations are in direct opposition to the model-based predictions of the IPCC.