A Raft of Climate Change Research at SD

Science Daily posted a few stories on climate change in the past two days, all three of equal interest.

The first study looks to the melting of the ice sheets that once covered the British Isles and how that affected ocean currents thousands of years ago. Will the same be true of Greenland's melting glaciers?

According to a revision article published in Science, ocean circulation during the last ice age was very different to present day circulation. The formation of deep water currents in the North Atlantic was much weaker and the flow of warm water from the Gulf Stream decreased. This led to a cooling of the northern hemisphere and contributed to the formation of the great ice caps which covered North America, Scandinavia and Europe.

In a similar study, the marine sediments of the North Atlantic were observed in order to document the sequence of events that led to that disturbance. The melting caused a significant decrease in the Gulf Stream, which transports warm water from the Gulf of Mexico to the North. This submerged the region of the North Atlantic into a period of glacial cold which lasted at least 1,200 years.

Number two comes from Stafford, taking a look at the effects of climate change on Indonesian agriculture.

In the study, the researchers looked at the impact of climate on Indonesian rice farming since 1983. Indonesia has two rice harvests-the main harvest in December and January and a smaller one in late spring. Because summers are dry, rice stocks often diminish and prices rise in the autumn, which Indonesians call the "hungry season." Planting for the main harvest usually begins in October with the coming of the monsoon rains.

The researchers found that rice production since 1983 has been greatly affected by year-to-year climate variability-especially El Niño/Southern Oscillation events, which occur in the Pacific Ocean every two to seven years. During a warm El Niño, the arrival of the monsoon rains is delayed, prolonging the hungry season and disrupting the planting of the main December-January crop.

The last deals with Antarctica. Scientists were able to extract several sediment cores from beneath the Ross Sea, which gives them a bit more substance to work with when reconstructing the continent's natural and climatic history.

They were surprised, for example, to find such large volumes of fossil diatoms -- microscopic single-celled algae that live in surface or shallow waters -- in the cores. The presence of the fossilized one-cell creatures, some of them previously unknown to science, confirms that large areas of the Ross Ice Shelf have previously melted and were replaced with highly productive open waters.

Studies of the cores may provide scientists with glimpses into the planet's future if predictions of global temperature increases are accurate. Either way, they say, data from the cores will help create more accurate climate models for predicting future trends.