Will the Southern Ocean carbon sink hold?
Ice core records show there was a sharp rise in carbon dioxide in the atmosphere – a nearly 50% increase – at the end of the last ice age. Scientists have long puzzled over the origin of all the extra CO2 that appeared as the great ice sheets melted.
Now, new evidence published in Science this week confirms that the gas emerged largely from the deep waters of the Southern Ocean as changes to ocean currents and circulation disrupted an enormous carbon sink there. Scientists looked at radiocarbon levels in the shells of microscopic animals which lived both near the surface and on the bottom of the Southern Ocean, and found large quantities of carbon locked away in ‘old deep water’ around Antarctica.
The dissolved CO2 accumulated as organic matter died and sank to the ocean floor. Around 19,000 years ago, when the largest ice sheets starting melting, current and circulation changes brought this deep water up to the surface, in the process releasing large amounts of CO2 into the atmosphere. The question scientists are looking to answer is whether global warming could cause a major increase in CO2 to be released into the atmosphere from the Southern Ocean in the coming years.
New Zealand scientists weigh in with their views on the paper here.
“We could also say that this new study further reinforces the disproportionate importance of the Southern Ocean in modulating global climate both in the geological past, present day, and in the future,” said Dr Philip Boyd of NIWA’s Centre of Chemical & Physical Oceanography at the University of Otago.
“In addition, the authors provide compelling evidence of both the important coupling of ocean and atmosphere processes and the strong communication, of effects of climatic change, between the waters of the Northern and Southern hemisphere through global ocean circulation.”
State of play on synthetic biology
In the wake of Craig Venter’s creation of a synthetic bacterium genome as outlined in Science last week, the Ministry of Research, Science and Technology has presented a snapshot of how synthetic biology is developing, which will serve as a useful backgrounder for journalists covering this fledgling field.
Futurewatch – Trend Summary Synthetic Biology points out that there has been a spike in published journal articles on synthetic biology in the last three years with around 250 articles published last year. Developments in this area are taking two paths – an extension of genetic modification and the more ambitious creation of completely novel organisms, which is where Venter is leading the way. New Zealand has little science underway in this area:
“Currently there is limited synthetic biology research occurring in New Zealand. Researchers from the Auckland Bioengineering Institute, at the University of Auckland have developed a mathematical modelling framework and models to aid in the design of synthetic biological systems,” Futurewatch reports.
“While most important developments will occur in other countries, fundamental research is moving relatively quickly and aspects may be taken up here. It can be anticipated that as the techniques develop, New Zealand researchers can be expected to also experiment with more sophisticated genetic modification in the laboratory.”
Organisms developed using synthetic biology techniques are considered genetically modified organisms in New Zealand and are covered by the HSNO Act, requiring the same type of regulatory approval existing GM trials require.
Meanwhile, New Zealand commentators have been commenting on the significance of Venter’s breakthrough.
Says Gareth Jones, director of the Bioethics Centre and a professor of anatomy and structural biology at the University of Otago:
“As with all previous developments, the positives and negatives are uncomfortably intertwined. There needs to be intense public discussion over what may be some of the implications of developments in this area. However, that debate needs to be realistic, and should not become submerged in grandiose hypothetical scenarios that will probably never come to pass.”