3 July 2010
Drilling For Ancient Ice At The Top Of The World
Posted by Dan Satterfield
On the 11th of January I was lucky enough to join a rather small club. Those who have stood at the very bottom of the world.
While I saw a lot of the science underway in Antarctica, there was one site in Antarctica I didn’t get to see, WAIS Divide. The Western Antarctic Ice Shelf is the site of one of the most important science projects in the world right now.
Researchers there are drilling through the ice to obtain an ice core that will tell us about the past climate of Earth. It will not be the first ice core, but this one will give detail that has never been seen before.
WAIS Divide is more remote than the South Pole and the weather was too bad to get in there. The text books will someday have a lot about these cores. They may very well ask how the nations of the world could ignore the warnings they gave (while burning fossil fuels at an ever increasing rate) as the planet warmed.
NEEM IN GREENLAND
There is another ice core being drilled at the opposite end of the world and in a place just as remote. The site is called NEEM. That stands for Northwest Greenland Eemian ice core.
The site is on top of the Greenland ice cap at over 8,000 feet. In summer, the top of the icecap is the coldest place in the Northern Hemisphere )with the exception perhaps of the top of Mt. Mckinley in Alaska).
The NEEM site was chosen because it may very well be possible to obtain ice with year to year countable layers that extend all the way back through the last ice age to the warm period before it!
The last ice age started about 115,000 years ago. The warm period before is called the Eemian (115,000 to 130,000 ybp). Temperatures in Greenland were likely 3-5C warmer then than they are today in the present interglacial. (The last ice age ended about 11,000 years ago)
Having two cores from opposite ends of the world will give paleoclimate researchers the best understanding of how are planets climate has changed over the last 130,000 years. They may very well confirm the estimates of what is called the climate sensitivity.
The climate sensitivity sounds complicated but like most things in science, if you take the time to understand it, it is really pretty simple.
Here are the basics and the big question all in one:
If you double the carbon dioxide in the atmosphere, how much does the Earth warm?
Climate models and ice cores obtained over the last 25 years all seem to indicate a sensitivity of about 3-4 degrees C. Most research shows it is not likely less than 2C but it could be higher than 4C.
If this is indeed true, then you don’t need a climate model to forecast the weather at the end of this century. The CO2 levels are rising rapidly and will reach the doubling point long before 2100. The CO2 is actually rising faster than predicted by the IPCC and will soon hit 400 parts per million. When Thomas Jefferson signed the Declaration of Independence it was about 280 ppm.
Rewriting The Text Books
Previous ice cores have already rewritten the climate text books. I was taught back in the late 1970’s that climate changes very slowly. Not enough to be perceptible in one life time. The Greenland cores have shown that the climate there changed many times, to much warmer conditions in just a couple of decades!
This was stunning information.
It’s why climate experts like James Hansen worry about so called tipping points.
Now that we are controlling the CO2 (not mother nature), could something like that happen again? Hansen thinks so and believes that we are already at a level of CO2 where it could. (A world 4C warmer than today would be dramatically different with likely catastrophic consequences)
The ice cap at NEEM is over 2,500 meters thick and at the bottom is ice from snow that fell 130,000 years ago! If all goes well, researchers in late July will be handling the most ancient Greenland ice humans have seen. (Antarctic cores have gone back even further).
Embedded in it will be a record of the temperature, and a host of other variables. That ice has locked in it the story of what that world was like when those soft snow flakes drifted down onto the icecap so incredibly long ago.
So now that you know why these ice cores are so important, I can tell you my disappointment at not reaching WAIS Divide was short lived.
Would You Believe??
I’ve been invited to visit NEEM in about three weeks!
Not many people get to stand at the bottom and the top of the planet inside of one year. If ever!
If all goes well the same New York air guard unit that flew us to the South Pole will land me on top of the Greenland Ice cap, well north of the Arctic Circle, in a few weeks. A land of 24 hour daylight at the top of the world.
More coming soon about NEEM and details about the ice cores and what modern science can tell about the past by analysing them.
If all goes well, I will see history first hand in a few weeks, and yes, I am bringing cameras.
All I can say is I am envious of your good fortune to be travelling to both ends of the globe in the same year.
I like the article and look forward to some in depth write-up on the subject of ice core science later.
I reckon that we don’t need to double the CO2 to cause a problem. We are already seeing enough dramatic changes already and we are only up to 400ppm CO2. Maybe if you had a graph showing how the CO2 relates to the changes we see around us rather than a graph of temperature would have a greater effect on peoples perception of climate change? I will leave you to contemplate the point.
Good point and I plan on adding a couple in the next post about the ice cores. A busy week ahead with a day trip to Baltimore to get ready for Greenland but that post is in the works..