It is thought, that the Northern Hemisphere experienced only ephemeral glaciations from the Late Eocene to the Early Pliocene epochs (about 38 to 4 million years ago), and that the onset of extensive glaciations did not occur until about 3 million years ago. Several hypotheses have been proposed to explain this increase in Northern Hemisphere glaciation during the Late Pliocene.
To understand what has happened to the earth's atmosphere--and, therefore, how our climate might change in the future--some ice-core scientists in the Arctic are training their eyes directly downward. It's an incredibly important job. It's also, as the participants in the North Greenland Eemian Ice Drilling (NEEM) project will attest, incredibly fun.
As the world heats up, the sea levels are rising. Many experts warn that dramatic sea-level rise is global warming's biggest danger. Two main factors are behind this: thermal expansion of the ocean and melting Ice.
First, as the ocean gets wanner from global warming, its volume expands. This is basic science: water expands as it heats up. Thermal expansion has raised the oceans about 10 to 20 centimeters (4 to 8 inches), according to the International Panel on Climate Change (IPCC).
The meltdown in the Arctic is speeding up and as a result the North Pole could be ice-free by 2013 instead of in 60 years' time as earlier predicted, scientists have warned.
Their apprehensions are based on computer studies of satellite images that reveal that ice at North Pole melted at an unprecedented rate last week, the disappearance is said to have exceeded the record loss of more than a million square kilometres in 2007 as global warming tightened its grip.
Sometimes you just wish you were a photographer. I simply do not have the words to describe the awesome majesty of Greenland's Kangia Glacier, shedding massive icebergs the size of skyscrapers and slowly pushing them down the Ilulissat Fjord until they crash into the ocean off the west coast of Greenland. There, these natural ice sculptures float and bob around the glassy waters near here. You can sail between them in a fishing boat, listening to these white ice monsters crackle and break, heave and sigh, as if they were noisily protesting their fate.
Jorgen Peder Steffensen made me an offer I couldn't refuse: "If you come to Copenhagen, I will show you a real Christmas snow, the snow that fell between 1 BC and 1 AD."
Now that's an offer you don't get every day! But then I don't go to the Arctic Circle every day. "I can also show you a sample of the very last snow that fell right at the end of the last ice age, which was 11,700 years ago," said Steffensen.
geology Climate change in ice age Greenland ice core analysis showed drastic climate change near the end of last ice age. Scientists have found two huge temperature spikes in the Northern Hemisphere prior to the close of the last ice age, about 11,500 years ago. They ascribe it to fundamental reorganization of atmospheric circulation. The ice core showed that the Northern Hemisphere
Listening to the earth scientists at the Tallberg Forum speaking about the likely calamities caused by global warming, I had the sensation of entering a parallel universe. It is a universe where an adaptive and inventive human race has grown to over six billion people, created bountiful and rich civilisations built on fossil fuels, and has emerged as the most important specie to geologically alter the planet. Man-made greenhouse gas has placed the earth in a slow cooker. In this parallel universe, the phrase
