At the Planet Under Pressure conference in London, Diana Liverman and Will Steffen present something of a contrasting couple. [Ed note: I assume that means Liverman is a rational individual]
The two professors have been working together on a State of the Planet report, which has involved trawling through numerous reports and scientific papers. At the end of it all, the message of one appears somewhat optimistic, the other fundamentally pessimistic.
They agree that changes to the world since about 1950 have been startling – rapid spread of the human population, accelerating exploitation of forests and marine resources, surging economic growth in successive waves across the world, and so on.
This radical reshaping of the natural world by a single species is certainly unprecedented in Earth history, which a few years back led to scientists Paul Crutzen and Eugene Stoermer coining a special name for our epoch – the Anthropocene.
(The Planet under Pressure organisers have made an animated video of humanity’s journey of expansion, by the way, which you can see here.)
If you accept the premise that we have entered the Anthropocene, one of the over-arching questions is “what happens now?”; another is “can we get out of it?”
Prof Liverman, who studies social aspects of global change at the University of Arizona, has the task of assessing the societal trends that either indicate we’re heading further into Anthropocene territory or beginning to back out.
Since 2000, she says, some trends have begun to reverse – in particular human fertility, which has halved globally in the past few decades as women have had progressively more access to family planning and maternal health services. In time, this should see the global population stabilise.
There has been a change in food production too.
“In agriculture, the big idea used to be that we destroyed tropical forests [in order to raise food production],” she says.
“What we’ve seen is that is turning around in some parts of the world where people are growing more food without encroaching on forests – in countries such as Vietnam, the forests are starting to return.”
The carbon intensity of industry has reduced too. Companies are finding ways of doing business that are more frugal with energy than before, and saving money in the process.