|Credit: USDA / E.L. Skidmore (usage does not imply endorsement of this site)|
Scientists from the University of Arizona recently announced that what is now the Sahara desert was once wet and green and extended as far north as the Mediterranean Sea.To read the rest, click on "More Evidence of a Wet Sahara".
The scientists examined chemical clues found within leaf waxes preserved in four marine sediment cores located off the northwestern African coast. Plants experience subtle changes in the chemical composition of their wax, depending upon the wetness or dryness of the climate. Because leaf wax washes into the oceans, it can be preserved in sediment cores extracted from the ocean floor. Hence, this team of researchers used wax chemical clues found within these cores to infer past climate conditions in the Sahara.