​Australian-based scientists are punching holes in Antarctica's sea floor to measure the impact of climate change on one of the world's most important oxygen producers.
The research team has mapped the unexplored Sabrina Coast sea floor for the best places to take ancient DNA samples of phytoplankton, or microalgae, that scientists say generate half of the planet's oxygen supply.
PHOTO: Dr Armbrecht says microalgae provide an important view into the past. (Supplied: Asaesja Young/CSIRO)

Dr Linda Armbrecht from Macquarie University said it was the first time the sampling had been done in that part of the world.
"The ancient DNA analysis is a new way of getting a complete picture of who thrived or didn't thrive in the ocean when past climate change has happened," Dr Armbrecht said.
"Phytoplankton is important for a range of reasons. It's the base of the food web, feeding krill, fish and ultimately whales.
"And they're important oxygen producers; every second breath we're taking is because of phytoplankton."
PHOTO: Diatom are a major group of algae, and among the most common types of phytoplankton. (Supplied: Dr Linda Armbrecht)

Dr Armbrecht is one of 22 scientists on board the CSIRO's Investigator research ship, on a 51-day mission in the region.
She said microalgae sink to the sea floor and were preserved, providing an important view into the past.
"We know it's happened but we don't know how they phytoplankton reacted. If we know that we'll have a better idea of what might happen in the future," she said.
The team is trying to look back as far as 30,000 years, taking sea floor samples at depths about 2,500 metres below the surface, to measure different periods of time.
Dr Armbrecht said microalgae was an important climate indicator.
"Phytoplankton are very sensitive to environmental conditions. They grow very fast and react quickly to changes in temperature," she said.
"We know now how phytoplankton react to certain temperatures and if we look at them from the past we can estimate how they'll react in the future."

​The Earth passed another unfortunate milestone May 23 when carbon dioxide (CO2) surpassed 400 parts per million (ppm) at the South Pole for the first time in 4 million years.
The South Pole has shown the same, relentless upward trend in CO2 as the rest of world, but its remote location means it’s the last to register the impacts of increasing emissions from fossil fuel consumption, the primary driver of greenhouse gas pollution.  
“The far southern hemisphere was the last place on earth where CO2 had not yet reached this mark,” said Pieter Tans, the lead scientist of NOAA's Global Greenhouse Gas Reference Network. “Global CO2 levels will not return to values below 400 ppm in our lifetimes, and almost certainly for much longer.”


South Pole carbon dioxide record
Daily average carbon dioxide levels rose to a new high level of 400 parts per million on May 23 for the first time in four million years. This chart shows readings at the South Pole from 2014 to present, as recorded by NOAA's greenhouse gas monitoring network. Credit: NOAA
Over the course of the year, CO2 levels rise during fall and winter and decline during the Northern Hemisphere’s summer as terrestrial plants consume CO2 during photosynthesis. But plants only capture  a fraction of annual CO2 emissions, so for every year since observations began in 1958, there has been more CO2 in the atmosphere than the year before. 

Last year’s global CO2 average reached 399 ppm, meaning that the global average in 2016 will almost certainly surpass 400 ppm. The only question is whether the lowest month for 2016 will also remain above 400.
Upward trend continues
And the annual rate of increase appears to be accelerating. The annual growth rate of atmospheric carbon dioxide measured at NOAA’s Mauna Loa Observatory in Hawaii jumped 3.05 ppm during 2015, the largest year-to-year increase in 56 years of monitoring. Part of last year’s jump was attributable to El Nino, the cyclical Pacific Ocean warming that produces extreme weather across the globe, causing terrestrial ecosystems to lose stored CO2 through wildfire, drought and heat waves.
Last year was the fourth consecutive year that CO2 grew more than 2 ppm – which set another record. This year promises to be the fifth.

COP22 Global Climate Summit.   Speaking at SIGEF/COP22

John Bird and Yonathan Parienti at SIGEF Palais des Congres COP22