New Discoveries in Climate Change

Clever new icebreaking techniques allowed scientists to drill over 400 meters of seafloor core, clarifying climate change over the past 56 million years. By using three icebreakers--one to maintain station over the drill site, and the other two to fend off ice flows--the scientists were able to remain on station at each of four drill sites for up to 9 days.

Results of the 2004 research expedition, led by scientists from the University of Rhode Island and Stockholm University, are reported in the June 1 issue of the journal Nature.

“Little direct evidence about the environmental history of the Arctic Ocean existed before our cruise, partly because of the enormous technological challenges of collecting the samples,” said Kate Moran, professor of oceanography and ocean engineering at URI and co-chief scientist on the expedition. “Our analysis of the core sample suggests that 55 million years ago the Arctic was much warmer than today. We anticipate that our data will be used by climate modelers to give us better information about how climate change occurs and where global climate might be heading.

....The sediment cores provide a surprising Cenozoic Era record of a climate transition from a warm “greenhouse” world in the late Palaeocene and early Eocene epochs to a colder “icehouse” world influenced by sea ice and icebergs from the middle Eocene to the present.

The researchers discovered that 55 million years ago, during a period called the Palaeocene Eocene Thermal Maximum, which was similar in climate to today, the surface temperature of the Arctic Ocean was much warmer than previously believed – perhaps as much as 20 degrees Celsius higher than today. The team was also surprised to find the remains of a large quantity of freshwater ferns, dated to 49.5 million years ago, which suggests that the ocean had considerably lower salinity levels and conditions amenable to the formation of sea ice.

Pebbles and sand in the sediment cores – debris that fell out of floating ice – is evidence of climate cooling 45 million years ago, about 35 million years earlier than previously believed. The revised timing of this Arctic cooling coincides with similar events in Antarctica, supporting the belief that global climate changed symmetrically at both poles.

....This Arctic Coring Expedition was undertaken by the National Science Foundation-sponsored Integrated Ocean Drilling Program, an international research effort that explores the history and structure of the Earth as recorded in seafloor sediments and rocks.....The drilling was done at four sites on the Lomonosov Ridge, approximately 1,000 meters under the sea-surface and 250 kilometers from the North Pole. Source.

The definition of an "ice age", is a time when the earth's poles are covered by ice. By that definition, the earth has been in an ice age for millions of years, with periodic periods of increased glaciation punctuated by much shorter inter-glacial periods. Climate change is merely part of the normal way of earth's climate.

Whether or not humans represent a serious destablising force in earth's climate or not is still a matter of serious debate among scientists. Certainly the sloppiness of many climate "scientists" lends a lot of ammunition to skeptics.

Regardless, it is nice to see real science being done, science that can shed real light on the topic. The earth has been through a lot over the past four billion years or so.