October 25, 2010 | General

Climate Change Connections: Age of Anthropocene

BioCycle October 2010, Vol. 51, No. 10, p. 42
Sally Brown

I recently saw an announcement that a revival of Hair is coming to Seattle. I was tempted to get my son tickets. Hair was the first Broadway play that I ever saw. I was thrilled when they started singing “This is the dawning of the Age of Aquarius.”
In August, I attended the World Soil Congress in Brisbane, Australia, the international soil science meeting that takes place every four years. They had quite a slate of talks this year, including one on the dawning of the Anthropocene, the human influenced geological era that has begun, following the relatively tranquil Holocene. After a week of talks on the Anthropocene, climate change as a reality, and upcoming water and food shortages, I found myself yearning for the Age of Aquarius. I’m afraid to report that after reading this column, you may too be looking for a revival of Hair to get your mind off of our future.
Let’s start with the talk, “Soils in the Anthropocene,” given by Will Steffen, the executive director of the Climate Change Institute at the Australian National University. He went through the changes in temperature and loss of Arctic sea ice. But then he started to broaden out the discussion. Climate change is just one part of this big picture. Steffen talked about the decline of fisheries, how changes in ocean pH (it is acidifying) are killing coral reefs and the oceanic food chain. Fifty percent of all fish stocks are fully exploited, and another 28 percent are depleted. This might be a good time to book that Alaska fly fishing trip.
Steffen also discussed the human imprint on the terrestrial biosphere, including fertilizer use and depletion (we have about 50 years of phosphorus reserves left). He talked about the global demand for Earth services versus the supply. We started needing more than one earth to keep up with our demand in about 1985. Steffen described the resilience of the earth systems, ecosystem services, how far out of whack we’ve pushed different cycles and whether they would be able to recover. We are now well into the threshold or past the threshold for many of the planetary boundaries.
For example, we are seeing a human-induced increase in the species extinction rate of as much as 1,000 times more than have occurred over our planet’s history. We are well past the boundaries on that one, as we are on the biogeochemistry of nitrogen. Past the boundaries on climate change. Getting close but not over the edge yet on ocean acidification, ozone depletion, global freshwater use and land system change.
Need a scotch yet?
This is all the result of our new, human-induced geological age. The Holocene was a period of stability. Very stable temperatures allowed the beginning of agriculture – very, very recently compared to the long eons of hunting and gathering. Steffen showed lots of graphs with predictable patterns until the very end, when we humans really got going. It was about 1950 that things started going to hell in a hand basket really quickly, the “great acceleration.” And it wasn’t just Lucy and Ethyl at fault. The root cause of this acceleration – the big thing that no one in climate change really talks about – is the fact that there are too many people. Things really got bad and are going to get worse with logarithmic population growth.
That was perhaps the most upsetting of the lectures but there were others. There was the one that I skipped about when large-scale famines are expected to start (about 2020). Another one about impending water shortages and how we might manage that I did go to. Turns out that Asia is in much worse shape than Africa for water. I also went to a whole session on soil salinity. Here I heard the brave woman from China give a lecture in English on using melted sea ice to irrigate cotton. The area of China where she works has exhausted their fresh water resources. Sea ice, can you imagine?
I also heard a guy from Bangladesh. (Where is George Harrison when you need him?) About a third of the country is expected to be below sea level in the next 50 years, with saltwater intrusion contaminating the fresh water supplies for a significant portion of what will be left above sea level. Each person in Bangladesh uses about one-fourteenth of the energy that we do in the U.S. One of the questions started with an apology from those of us responsible for destroying their country.
One of my jobs at the meeting was to go to the Council committee sessions where the locations of the upcoming Congresses were decided. Paul Bertsch, the head of the U.S. delegation, just wanted to be sure that there would be food at the 2022 meeting. I wanted to be sure of the elevation of the convention center and associated airport.
Composting isn’t going to make this all go away any more than seeing a revival of Hair will. The best thing that we can do is to stop having lots of children. In much of the developed world, we’ve already started to do this. Invite friends and neighbors and Thanksgiving will still be nice.
The only way to maybe make this so that our world survives in a somewhat recognizable fashion is to use every tool that we know is effective. One of the clear messages of the World Soil Congress is that soil carbon sequestration is one of the best tools that we have. As I’ve talked about here many times before, adding organics to soils increases soil carbon concentrations. Organics also provide a substitute for synthetic fertilizers, thereby eliminating emissions associated with their manufacture. Composts improve soil tilth, which includes improved water infiltration and water holding capacity. And improves yield. With all of these things, organic amendments make our soils healthier and more resilient. Resilience is a key to facing the challenges that lie ahead.

Sally Brown – Research Associate Professor at the University of Washington in Seattle – authors this regular column. E-mail Dr. Brown at

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