The shock of the 'human new'

A Nobel Prize-winning chemist believes the impact of human pollution on Earth is so great that our geological era should be renamed, writes DICK AHLSTROM

HUMANS HAVE made a right mess of the Earth, scarring its surface, polluting water and air and even altering climate on a planet-wide basis. Our depredations have triggered what looks like becoming the worst mass extinction event of all time.

This destructive capacity entitles the geological era in which we live to be known as the “Anthropocene”, according to the Nobel Prize-winning chemist who coined the term.

Prof Paul Crutzen first used the term, which translates from the Greek as “human new”, at a conference in 2000. He believes it fits much better than the official name for our current geological era, the Holocene (“whole new”).

"The Anthropocene is a geological time which is to a growing degree defined by human activities," says Crutzen, the former director of the Max Planck Institute for Chemistry in Mainz, Germany. He was speaking this week in advance of an Academy Times lecture he will deliver in Dublin this evening, organised by the Royal Irish Academy, The Irish Timesand Invest Northern Ireland.

He quickly lists a collection of impacts on the planet caused by human activity, including urbanisation and a growing human population but also animal populations, industrial pollution, disruption of fresh water systems, out-of-control energy use, the collapse of international fisheries and more.

“This is unique [to humans] and is still growing,” he says. With the developing countries becoming more economically active it is certain there will be “a great acceleration of human impacts on the environment”, he believes. Human activity can rival natural planet-wide processes in terms of scope and impact, he says. We now introduce more nitrogen-based fertilisers into the environment than the planet can produce on its own through nitrogen fixation.

“Now the human influence is starting to dominate and that is why I think it is justified to describe the current era with the new term,” he says.

Stabilising atmospheric carbon-dioxide levels would require between a 60 and 80 per cent reduction in output, he says. “What we see instead is the output of carbon dioxide is increasing by 3 per cent a year, and with nothing like a reduction.”

Born in Amsterdam in 1933, Crutzen shared the Nobel Prize for chemistry in 1995 for his work on understanding the hole in the ozone layer. The banning of CFCs has proven to be one of the few examples where we have managed to reverse human-induced damage.

“We can do something, but it is much more difficult when it comes to carbon-dioxide output,” he says. “We can do something about it, it just isn’t happening.”

Crutzen caused controversy some time ago after proposing a way to cool the global climate by releasing sulphur into the upper atmosphere, where it would produce clouds to reflect away sunlight and heat.

“Maybe the only solution, and I don’t like to call it a solution, is geo-engineering to cool the planet,” he suggests.

It would require research, however, to anticipate unforeseen impacts caused by this radical approach. “We have to be sure we don’t upset the situation more than what we are doing now.”

Although officially retired, he continues to research issues related to human impact on the planet. In 2008 he published findings that the significant release of nitrous oxide during biofuel production meant this “environmental” activity could actually contribute more NOX to global warming than use of fossil fuels.

He views current attempts to address the degradation as pitiful, something that makes him believe a contingency plan is now needed.

In an essay written in 2006 in the journal Climate Change, he suggested that an “escape route” is needed should global warming begin to run out of control.

The Academy Times lecture, The Anthropocene: A New Geological Epoch Dominated by Human Activities,takes place this evening at 6.30pm in the Burke Lecture Theatre, Arts Block, Trinity College Dublin. A limited number of seats remain. To book use the academy's website, ria.ie, and click on the Crutzen lecture