Download - New Zealand Society of Soil Science

Editorial
By Kevin Tate
The surprisingly rapid onset of global warming and associated feedbacks is graphically shown by e.g.,
accelerated ice melting in both hemispheres, species extinctions and increasing methane ebullition
from the Arctic tundra. These dramatic changes are occurring at the same time as oil prices are rising
and peak oil production is apparently imminent.
Both these recent developments pose stark warnings for urgent action to break our dependence on
fossil fuels. Central to our response is the question of how we will feed and clothe a burgeoning
human population in a warmer world without reliance on oil. What alternatives to this hitherto cheap
energy source do we have for production, processing, packaging, transport, and storage? Biofuels are
one possibility but, increasingly, scientists in many parts of our world are concluding we simply don’t
have the land available to grow food and produce energy. Moreover, biofuel production from crops is
often associated with very unfavourable input: output energy ratios and associated enhanced
greenhouse gas emissions.
Clearly, soils and how we manage them will be crucial in our response, both globally and in New
Zealand. In New Zealand, we do have the land for both food and energy production, and cleanly, if we
choose crops like willow or pampas grass (Miscanthus) for biofuels. But, we concluded several years
ago that our soils might lose 5–6 % of their carbon (and associated nutrients in soil organic matter),
based on projections of global warming by 2100. More intense storms and droughts are also likely,
adding to these losses. Warmer temperatures mean greater decomposition, especially with adequate
soil moisture. The greater inputs of C from CO 2 fertilization may not compensate for these losses, but
may simply increase cycling. More varied landscapes may offer some relief, with trees helping to
ameliorate these warmer temperatures and slow down decomposition, as well as protecting soil against
enhanced erosion and providing fodder for animals.
One of the world’s leading experts on oil reserves has recently argued that the only way to avoid
global food shortages in coming decades is a planned and rapid reduction in fossil fuel use, and a
return to more organic methods of producing food. This view is supported by the current food riots in
some developing countries caused by rising oil and grain prices.
We already have technologies to achieve this, and, according to the Fourth Assessment Reports of the
Intergovernmental Panel on Climate Change (www.ipcc.ch), to also avoid catastrophic climate change
later this century. These reports, published in 2007, represent the combined wisdom of thousands of
the world’s leading scientists. They indicate that we still have time to act and many of the
technological solutions we need are already available. The question is: do we have the resolve to plan
and act quickly enough, against a background of dwindling supplies of oil?
Response to the Editorial by Peter Singleton (December 07)
Regarding Peter Singleton's editorial (December 2007) here in Taranaki we have had a long term
chairman of the Regional Council and he and the Chief Executive have given policies direction over
many years and so we are fortunate. With regards to water quality; we have 1916 dairy farms and
480,000 cows and if it wasn't for the riparian planting along ditches, streams and rivers, our water
purity would be so much poorer. The prison has a large garden and thousands of native plants are
cultured by prisoners and these are planted out by offenders on community work. This has been going
on for at least 25 years. The Corrections Department has just bought land in Christchurch for prisoners
to grow plants and so there may be an avenue for Environment Waikato to lobby Corrections to
purchase land in the Waikato so that intensive riparian planting can occur.
Theo Wilms
71 Fulford St, New Plymouth
47