| Summary: | Permafrost regions cover approximately a quarter of the Northern Hemisphere and thawing has been recorded in many different locations. The thawing process is likely to continue given that the Northern Latitudes will experience increased warming, which is known as the Arctic Amplification Factor. Changes in permafrost regions can cause changes in hydrology, biogeochemical cycles and ecosystems. Furthermore, infrastructure built on permafrost grounds such as cites and oil and gas pipelines are at high risk of collapse in the event of thawing. Additionally, there are large carbon pools stored in regions of frozen ground and release of carbon dioxide and methane could enhance the effect of global warming. While decrease in permafrost and its hazards have widely been recognized there is uncertainty about the extent of loss in permafrost area under different warming scenarios suggested by the IPCC. Models differ by their application so that global models are generally process-based and models in mountain areas often use statistical models. A previous study found a strong correlation between mean annual air temperature and current permafrost extent. This thesis investigates the relationship between growing and freezing degree days, seasonality and soil organic carbon content with regard to current permafrost extent and predicts permafrost loss for the RCP4.5 scenario. All variables are expected to show better or equal correlation coefficients as the mean annual air temperature as they give a more precise indication of the freezing conditions, which is supported by findings of previous local studies. The results show that none of the variables are a better indicator for permafrost. However, the predicted loss of permafrost by growing degree days with base temperature 5°C falls within the confidence interval of the permafrost-mean annual air temperature prediction. Permafrost describes ground that is frozen continuously for two years or more and occurs in in polar and mountainous regions in both hemispheres. Decrease ...
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