Nothing, at this stage, will save the Greenland ice cap from melting, raising oceans several feet, says Victor Shahed Smetacek.
Only a massive feat of “geo-engineering” can save the Antarctic ice cap from doing the same, the professor of bio-oceanography at the University of Bremen, Germany, said in an interview from Halifax.
Humanity, led by the United Nations, must remove huge quantities of carbon dioxide from the air over the next century, he will argue in an address at Mount Allison University this week.
Smetacek, born in India of an Indian mother and German father, attended the conference in Halifax this month of the International Council for the Exploration of the Sea.
A talk on rising oceans might interest an audience at a university in Sackville, on the Tantramar marsh.
Today, he will speak as part of the President’s Speakers Series on Climate Change and Global Citizenship. On Tuesday he will launch the vice-president’s seminar series Evolution: 150 Years of Darwin with a lecture, “Understanding plankton evolution in the framework of the arms race.”
Phytoplankton, microscopic organisms, might save humanity, he argues.
Smetacek quite seriously proposes to fertilize vast areas of the southern oceans deficient in iron to promote plankton to absorb carbon dioxide from the air through photosynthetic uptake.
Skeletons of dead plankton compose a large part of the sludge at the bottom of deep oceans. So, scientists must figure out how to promote plankton that remove carbon from the air, then take it to the bottom when they die.
We might remove a gigatonne – one trillion kilograms – of carbon from the air each year, Smetacek says. Removing carbon at this rate might save the south polar ice cap if other efforts continue to stop adding more carbon, he said.
Depositing a whole gigatonne of carbon at the bottom of the sea might sound like an effort worthy of Archimedes, the ancient Greek mathematician and engineer who said that he could move the Earth if he had a place to stand with his pry bar.
However, it would take only five to 10 ocean-going ships, possibly tankers or ore carriers, to fertilize the oceans each year with iron sulphate, a waste product from smelting titanium and iron, he said.
The ships would drift with wind and current. They might accommodate tourists, maybe summer students, who would underwrite part of the cost. They might even lend their labour to shovel the stuff overboard.
The project would cost in the hundreds of millions of dollars, rather than the billions or trillions it would costs for other geo-engineering proposals – such as seeding the upper atmosphere with particles to reflect sunlight back into space, Smetacek said. It could save hundrds of millions of people from being displaced, he said.
Efforts to reduce carbon emissions will not save the ice-caps without removing what we have already added over the past couple of centuries. “The amount of C02 we remove is too little to make any difference if we keep business as usual,” he said.
Adding a gigatonne of carbon each year to the deep ocean would not dangerously acidify seas, which already hold 38,000 gigatonnes of the element, he said.
Further, algae blooms would not threaten coastal fisheries by adding nutrients in the to the oceanic regions he has in mind.
“I would like the United Nations to organize this effort,” he said. “It should not under any circumstances be a private enterprise undertaking, because it has to be controlled.
He proposes a long-term program to remove 100 to 200 megatonnes of carbon at one gigatonne per year, enough, he hopes, to keep the poles cold.
He would not allow businesses to get out of painful and expensive measures to limit carbon emissions by claiming credit for his oceanic fertilization program, because the programs to stop adding more must continue, he said.