Snapshot of past climate reveals no ice in Antarctica millions of years ago
July 28, 2008A snapshot of New Zealand's climate 40 million years ago reveals a greenhouse Earth, with warmer seas and little or no ice in Antarctica, according to research published this week in the journal Geology.
The study suggests that Antarctica at that time was yet to develop extensive ice sheets. Back then, New Zealand was about 1100 km further south, at the same latitude as the southern tip of South America – so was closer to Antarctica – but the researchers found that the water temperature was 23-25°C at the sea surface and 11-13°C at the bottom.
"This is too warm to be the Antarctic water we know today," said Dr Catherine (Cat) Burgess from Cardiff University's School of Earth and Ocean Sciences, and lead-author of the paper. "And the seawater chemistry shows there was little or no ice on the planet."
These new insights come from the chemical analysis of exceptionally well preserved fossils of marine micro-organisms called foraminifers, discovered in marine rocks from New Zealand. The researchers tested the calcium carbonate shells from these fossils, which were found in 40 million-year-old sediments on a cliff face at Hampden Beach, South Island.
"Because the fossils are so well preserved, they provide more accurate temperature records." added Dr Burgess. "Our findings demonstrate that the water temperature these creatures lived in was much warmer than previous records have shown."
"Although we did not measure carbon dioxide, several studies suggest that greenhouse gases forty million years ago were similar to those levels that are forecast for the end of this century and beyond.
Our work provides another piece of evidence that, in a time period with relatively high carbon dioxide levels, temperatures were higher and ice sheets were much smaller and likely to have been completely absent."
The rock sequence from the cliff face covers a time span of 70,000 years and shows cyclical temperature variations with a period of about 18,000 years. The temperature oscillation is likely to be related to the Earth's orbital patterns.
Source: Cardiff University
Nov 18, 2009 |
not rated yet |
0
Scary? I know I won't be losing any sleep over it!
In spite of the GW hysterics, data shows that high atmospheric CO2 FOLLOWS warming due to degassing of the oceans. IF the "suggested" higher CO2 concentration was real what effect did that have on reducing the ocean pH?? The foraminifers seemed perfectly capable of making CaCO3 based shells. Does this put to rest the latest GW fear mongering about CO2 lowering the oceans pH?
And never forget, at one time virtually ALL of the carbon in coal and hydrocarbons was once in the atmosphere as CO2 or dissolved in the oceans as carbonate and bicarbonate.
It weren't a republican. Down with socialism.
There is no world government and there never will be. Die like a warrior.
And the brave men and women who serve in our armed forces are really not men and women at all but only children?
And all the men and women in the Congress and the Senate are ignorant elders that planned the forced death of our children?
Rubberman, what is the weather like in your world?
In my world it is getting cooler.
Al gore?
Congress?
Armed forces? (This one is my favourite)
The country with the highest military budget on earth lives in fear of imminant attack from....Canada and Mexico? Yeah 200 billion seems like a reasonable dollar figure to prevent that. When was the last time an American soldier died from enemy fire on American soil? Hmmmm. 100% of all armed conflict that the U.S. has been involved in since WWII has been on the soil of foreign land. Perhaps instead of a Carbon tax some funds from the military budget could be re-allocated so as to not burden the tax payers ? ( I actually agree with the scientists who claim that the CO2 contribution to climate change has been severly over estimated) People who are concerned with climate change aren't alarmists (even though some of the changes we've been witnessing over the last 20 years are pretty alarming) Al Gore IS an alarmist, with a financially motivated agenda. Which, by definition, makes him a quintessential American politician. ( Using fear of a potential situation to- a) make money, b) tell other people what to do and c) claim that it is in everyone else's best interest (while merely acting as a figurehead for his financial backers who weild the real power)
Sorry if I offended your patriotic ideals Mike, but there are some undeniable facts about climate change and the USA. You will be the hardest hit because you have the most to lose (not necessarily in the truly meaningful currency of lives: plant,animal,human.But in the cost of adapting to the coming changes while trying to maintain your infrastructure.)The earth doesn't do things half assed, the climate cycle that has begun will complete before it reverses and to deny that anything is happening IS ignorance. Between the current environmental concerns, the emergence of China as the worlds industrial park, the discrepincy between the your ability to supply natural resources versus your demand for them,the recent sabbatical the U.S. dollar has taken from the top of the world currency market, American idol and the fact that most of the population cares more about that than the other issues mentioned here and the way that the rest of the world responds when you ask them what they think of your country...let's just say it's pretty stormy in my world, but at least i'm nowhere near the eye.
On global warming and defense we must agree to disagree. On Al Gore, right on!