Tag Archives: surprise

Volcano and global environmental surprise

Volcano eruption is certainly one, but which are other possible global surprises? In 1994, the Aspen Global Change Institute organized a two week workshop on global environmental surprise. The results from this workshop can be found in Stephen H. Schneider and colleagues 1998 article “Imaginable surprise in global change science” (Journal of Risk Research, 1(2)). By “imaginable surprise”, they mean

The event, process, or outcome departs from the expectations of the observing community or those affected by the event or process. Seen from this point of view, surprise abou t one or another aspect of climate change is an after-the-fact reaction to an observation or new scientiŽfic fiŽnding that, in some sense, lies outside our range of expectations.

In the list of 40+ types of surprises, you find not only volcano eruption, but also, just to mention a few:

  • A reduction in ‘conveyor belt’ oceanic overturning leading to cooling at high latitudes occurs, despite general (but slower) global warming.
  • Heat stored in the ocean at intermediate depths is released to the atmosphere, leading to rapid warming.
  • Dimethyl sulŽfide emissions decline with reduced sea ice, causing cloud brightness to decrease and warming to accelerate.
  • Dimethyl sulŽfide emissions change with sea-surface temperature change.
  • Synergism of habitat fragmentation, artiŽficial chemicals, introduction of exotic species and anthropogenic climate change affect ecosystems in unforeseen ways that reduce biodiversity.
  • Geo-engineering is practised intermittently by only a few nations causing international political conflicts and greater environmental instability.

    Don’t say you weren’t warned….

    Intensive agriculture’s ecological surprises

    regime shift cartoon from TREE paperRhitu Chatterjee has written a news article Intensive agriculture’s ecological surprises in Environ. Sci. Technol. (July 2, 2008) about a paper Agricultural modifications of hydrological flows create ecological surprises (doi:10.1016/j.tree.2007.11.011) that Line Gordon, Elena Bennett and I published in TREE earlier this year.  From the article:

    Previous reports have outlined ways that agriculture alters ecosystems by changing hydrology. The new study, led by Line Gordon of the Stockholm Resilience Centre, classifies these changes, or “regime shifts”, from one ecological state to another into three categories: through agriculture’s interaction with aquatic systems, as in the case of nutrient runoff; in the interactions of plants and soil, as in Australia’s salinity issues; or by influencing atmospheric processes such as evaporation and loss of water by plants (transpiration), as in the rapid drying of the Sahel in sub-Saharan Africa.

    The authors “make it clear that agricultural practices result in these regime changes by altering water quality and available quantity,” says Deborah Bossio, a water expert at Sri Lanka’s International Water Management Institute.

    “The increasing demand for food, feed, and fuel is placing enormous pressure on the world’s arable lands,” says ecologist Simon Donner of the University of British Columbia (Canada). Awareness of agriculture-related environmental problems has been growing in the past few years, says Bossio. But some of that awareness has been lost in the “current frenzy of global food crisis shifting the balance back toward increasing yield.”

    Be it the desertification of the Sahel, the dead zone in the Gulf of Mexico, or the increasing salinity in Australia, countries all over the world are already trying to solve some of these problems. But the fixes are not quick, and the results of their efforts are often hard to predict.

    Given the difficult-to-repair, or even irreparable, nature of the problems, agricultural systems must be made resilient to change, the authors argue. The new study adds to “the increasing chorus of voices” that emphasizes the need to avoid irreversible ecological damage, says Donner.

    However, the science of understanding ecological regime shifts is still young, which makes it difficult to predict when the changes will manifest. “The tipping points aren’t very well understood at all,” says Bossio. Researchers first need to understand the various biophysical factors involved and how those factors interact with one another, the authors say.

    For now, ecologists, agronomists, and regulators can acknowledge the problem and encourage certain practices to minimize the likelihood of some of these water-related changes. People should begin by viewing agriculture not simply as a source of food but also as a source of ecosystem services like water and biodiversity, says coauthor Garry Peterson of McGill University (Canada). For example, Australian farmers are adopting mosaic farming, which involves combining annual crops, pastures, and perennial trees into the same landscape. This restores biodiversity and hydrology and prevents the rise of salinity.

    “If we don’t heed the management lessons from the past, many of which are listed in the paper, we are bound to face many more ecological surprises in the coming decades,” says Donner.