Land Use Intensity Doubled In 20th Century
The growth of green
plants -- which can be measured in terms of "net primary production," or
NPP for short -- provides the energetic foundation for all life on
earth. The share of NPP appropriated by humans (HANPP) through
agriculture and forestry, bioenergy production, and vegetation fires
doubled over the course of the past century. Researchers at the
Institute of Social Ecology at the AAU have shown that while land is
used more efficiently, simultaneously, the intensity of land use has
increased continuously.
In a study published in PNAS (Proceedings of the National Academy of Sciences), researchers warn that an increased expansion of bioenergy use would drastically raise HANPP to over 40%.
In a study published in PNAS (Proceedings of the National Academy of Sciences), researchers warn that an increased expansion of bioenergy use would drastically raise HANPP to over 40%.
The growing global population and its increasing
hunger for resources gives cause for concern for various reasons, in
particular with regard to the sustainability of the current and future
use of natural resources.
The so-called HANPP indicator is a measurement for
the intensity with which humans use land and biomass. HANPP stands for
"Human Appropriation of Net Primary Production" and provides information
about the impact of human activity upon the biosphere. HANPP reveals
the percentage of the annual plant-based biomass production that is
co-opted by humans through land use activities such as agriculture and
forestry, bioenergy production, construction of buildings and
infrastructures, soil degradation, or human induced vegetation fires --
and thus not available to other ecosystem processes.
A study recently published in PNAS quantifies for
the first time long term trends in HANPP during global industrialization
covering the period from 1910 to 2005.
The authors arrived at a
surprising result: While global population increased fourfold over the
past century, and economic output increased 17-fold, HANPP "only"
doubled."This shows us that land use became more and more
efficient across the globe: The production of food and other products
has increased at a much faster rate than HANPP.
Nevertheless, HANPP has climbed from 13 to 25 per
cent during the past century," Fridolin Krausmann, lead author of the
article, explains.
While global consumption has increased dramatically,
the amount of biomass harvested and used per capita has dropped
significantly. Krausmann elaborates: "One of the reasons for this is
that -- seen from a global perspective -- bioenergy has increasingly
been replaced by fossil energy. Furthermore, efficiency of conversion
processes from biomass to products such as food or fiber has grown."
However, as the authors of the study point out,
there are major drawbacks: The impressive increase in efficiency gains
in crop and livestock yields have been achieved at considerable
ecological costs."In order to increase yields and output, we use
large amounts of fossil fuels and water, we turned to large-scale
industrial animal production systems and put high environmental pressure
on land, soils and biodiversity," Krausmann points out.
The authors assume that, given a continuation of the
past trends, global average HANPP is likely to increase moderately to
values up to 29 per cent by 2050.
However, if bioenergy is to be expanded by as much
as some IPCC scenarios suggest, the value could climb as high as 44 per
cent, clearly exceeding the growth rate observed over the past decades
and putting high pressure on ecosystems.
The researchers thus call for caution: "Caveats are
warranted concerning bioenergy strategies. The utilization of vast land
areas for the production of bioenergy can have a strong negative impact
on food safety, forest resources, and biodiversity. Unrealistic
expectations regarding bioenergy can result in failing to achieve the
target of reducing greenhouse gases. Above all, we have to focus on
sustainable intensification and we have to be careful to prevent any
potential negative consequences of forms land use intensification that
further increase the pressure on ecosystems."
Source:
Alpen-Adria-Universität Klagenfurt | Graz | Wien (2013, June 4). The intensity of land use doubled in the 20th century. ScienceDaily. Retrieved June 5, 2013, from
http://www.sciencedaily.com /releases/2013/06/130604094519.htm
The question that must be asked is whether those at the helm of national and international capitalist power will heed - (assuming they even hear) - these warnings.
No comments:
Post a Comment