Interpreting High-Resolution Proxy Climate Data — The Example of Dendroclimatology

Abstract

Current scientific concern to establish the reality, the nature and the speed of climate changes, believed by many to be the inevitable consequence of human activities, should serve to reinforce our determination to understand similar details of the “natural” (i.e. non-anthropogenic) variability of climate. Reconstructing past climates on all timescales is clearly important if we hope to understand the mechanisms that control climate (Bradley, 1990). However, the scope and the rapidity of the changes foreseen in many scenarios of an “enhanced-greenhouse” world, highlight the particular relevance of palaeoclimate studies that focus on recent centuries and millennia (Eddy, 1992). When considering the question “Can we detect an enhanced greenhouse signal?”, natural records of past climate variability (so-called “proxy” climate data) that are annually resolved and that capture decadal-to-century timescale variability, represent an essential basis for comparison with relatively short modern climate records which are rarely longer than a hundred years.