Fossilized Pollen Reveals Climate Clues
When it came to climate and weather, 2015 was memorable, though not in a positive way. It was a year in which the planet surpassed an ominous temperature threshold and saw both shrinking Arctic ice and continuation of a brutal drought. The National Oceanic and Atmospheric Administration says there is a 97 percent probability that 2015 will be the warmest year on record. Here are some other infamous global temperature peaks.Paris Climate Deal: What You Need to Know
July's average global temperature of 61.86 degrees Fahrenheit made it the hottest month ever recorded, narrowly surpassing the previous record in July 1998 by 0.14 degrees F.Photos: Global Warming Right Before Your Eyes
Library of Congress
According to data compiled by the UK's Met Office, by the end of 2015, the world will be 1 degree centigrade warmer than it was before the rise of modern industry, the first time that milestone has been reached. This photo depicts a Pittsburgh steel mill in the early 1900s, before pollution controls.War Of The Words: Climate Change Or Global Warming?
NASA Goddard Space Flight Center
When the Arctic Sea Ice Maximum of 5.61 million square miles was reached in late February, it was the lowest since NASA began tracking the ice by satellite in 1979.
Many parts of the United States had record-breaking amounts of precipitation. In Oklahoma, for example, May brought nearly 14 1/2 inches of rain, breaking a record set in October 1941 by nearly 4 inches.Photos: Global Warming Right Before Your Eyes
California endured the fourth straight year of a brutal drought that a study of tree rings indicates is the worst since Spanish explorers landed in the state in the early 1500s.Video: Why Doesn't Anybody Care About Climate Change?
Fossilized pollen is sometimes used to determine what sort of vegetation grew as Earth’s climate changed over time. But until recently, samples could only be dated back about 500,000 years, a relatively narrow window for study. But now researchers in Australia have found a way to date and examine pollen found in stalagmites of any age.
A new technique developed at the University of Melbourne allows researchers to date speleothems (stalagmites, stalactites and flowstones) and then dissolve them to examine the pollen inside.
“It is also home to a scientific treasure trove of palaeoclimate information that has potential global significance,” said Professor Jon Woodhead, from the University’s School of Earth Sciences.”
Samples from speleothems found in Australia’s arid Nullarbor Plain give clues to what grew in the area 5 million years ago when the area received four times as much rain.
“Most didn’t contain any pollen, which isn’t surprising since many speleothems grew in caves that had no openings to the surface,” palaeoclimate scientist Kale Sniderman said in a statement.
“But some did contain fossil pollen, which revealed the nature of the vegetation growing at those times. Through that we’ve been able to develop a new understanding of the history of the Nullarbor’s climate.”
The findings were published in the journal Proceedings of National Academy of Sciences.