Climate Change in the Arctic and its Empirical Diagnostics

Abstract

The Hypothesis that global climate warming observed during the last century is due to anthropogenically induced carbon dioxide concentration growth, has provoked controversy. In this context, general considerations are discussed which support the view that the ‘greenhouse’ global warming hypothesis is doubtful. Numerical climate modelling data ‘predicts’ that there must be an enhancement of the ‘greenhouse signal’ with latitude. Some results of surface air temperature (SAT) observations in the Arctic during the last 20–30 years demonstrate, however a reduction in SAT in several Arctic regions. Some dendroclimatic data fot the last 200–300 years relevant to tree growth near the northern forest boundary reveals that not ony the conclusoin about polar enhancement of climate warming is wrong but the warming itself could hardly be real. It is concluded that no uncontroversial information exists to support the hypothesis of global ‘greenhouse’ warming.