by Alexei HERMAN, Dr. Sc. (Geol. & Mineral.), Geological Institute, Russian Academy of Sciences
Studying samples of the fossil mid-Cretaceous flora (about 100 million years ago), paleobotanists seek to learn more about the climate of that distant geologic epoch, and they also try to peer into the future so as to visualize, and predict the probable aftereffects of upcoming global warming.
Weather vagaries of the past few years break all records indeed. The governments of many countries are gravely concerned about the ongoing climatic changes. This is understandable, clear: the heat wave of the sweltering summer of 2003 carried off as many as 20,000 lives in Italy and nearly 15,000 in France. Meeting in July 2005, the G-8 leaders discussed what could be done in the way of counteracting the global warming threat. The world community is now
Articles in this rubric reflect the opinion of the authors. - Ed.
Distribution of plant species with entire-margined leaves depending on mean annual temperature; this dependence is potted for present-day floras of Southeast Asia in areas not hit by droughts.
poignantly aware of the possible implications, and this awareness has spurred broader, in depth studies into the heart of the matter. In this context it is all important to cull geologic evidence about the earth's past climates. Well and good, but why should we get busy with plants-gone millions of years ago!-in a bid to forecast the scope of imminent cataclysms?
Lithological, isotope and paleontological studies provide us with important evidence on our planet's paleoclimates. Most of the data thus obtained, however, tell us only about what happened qualitatively-whether it was hot or cold, wet or dry. Scattered bits of evidence-collected by isotope paleothermometry and paleobotany-provide a glimpse of the quantitative characteristics of the past climate. Paleobotanists make a wide use of what they call leaf margin analysis on the ... Read more