Vegetation displacement issues and transition statistics in climate warming cycle

Abstract

Scepticism largely deflated, and the denial machine's intent to mislead unmasked, climate warming owing to anthropic carbon emission is now seen by most as an ongoing process. When compared to the historic rates, the predicted warming rate and concomitant rates of biotic response should be considered simply colossal. This is the point about which the present paper gives insight based on numerical analyses. The Vostok temperature series, its different transforms, and palynological spectra from global sites are the basic data. These are marshalled in support of the paper's main proposition that the thermal effect on the vegetation depends not only on the rate of troposphere warming or cooling, but very much on the velocity of onset and length of duration. The main text begins with a definition of terms, followed by a short essay tracing how the conceptualisation of the climate warming paradigm evolved from initial scepticism to acceptance as a reality. The technical sections treat the conversion problem from Vostok inversion-layer temperature differences to global mean rates. It offers frequency distributions for historic warming/cooling rates, and explains the latitude dependence of the translation of the rates into local thermal flux. Presentation of examples of historic thermal events and the effect on the global vegetation close the main text. Statistical analyses are involved based on a novel methodology. The methods are concerned with formation migration rates, metrics of compositional transition velocity and acceleration, long-term variation in the representation of specific taxa in palynological spectra, taxon traits and taxon plasticity, and hotspots detection in compositional transitions. The palynological data are examined in synchrony with historic trends in the troposphere's Late Quaternary temperature history. Owing to the broad topical contents, the paper adapts a modular structure of presentation which requires the evaluation and interpretation of the results where they are presented. An overview is given at the end with emphasis on the general trends. © 2008 Akadémiai Kiadó.