production of animal proteins by cell systems - New Harvest

Introduction
The use of livestock for the production of food has always been an essential part of man’s
existence on earth, and its impact has until recent years been primarily positive, both
economically and socially. However, current production methods are rather demanding.
Their impact may be direct, by ruminant methane production for example, or indirect,
such as expansion of soybean production for feed in South America, replacing rain
forests. About 70% of the fresh water use, 35% of land use and 20% of the energy
consumption of mankind is directly or indirectly used for food production, of which a
considerable proportion is used for the production of meat. The total area of ice-free land
in use for grazing is about 26% of the earth’s total, and an additional 33% of arable land
is in use for feed crop production. In total, livestock is responsible for 70% of agricultural
land exploitation, and without change of policies this percentage will only increase in the
near future.
It has been estimated that the global population will increase from 6 billion people in
2000 to 9 billion people in the year 2050. This population increase will be accompanied
by a rise in annual greenhouse gas emissions from 11.2 to 19.7 gigatonne of carbon
dioxide, carbon equivalent. It is anticipated that in the same period annual global meat
production will rise from 228 to 465 million tonnes due to rising incomes, urbanization
and growing populations (FAO 2006. Livestock’s long shadow, environmental issues and
options, Rome.
http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf).
The amount of additional land available for the required increase in production capacity,
however, is limited. This has serious consequences at various levels and makes it a major
policy focus. It is now evident that we are experiencing a climate change, and that
anthropogenic influences seem to be (at least partly) responsible for this. This includes
the current level of meat production. Feed crop production demands high levels of
energy, which in itself, leads to increased CO2 emission. Livestock species, particularly
ruminants, are responsible for greenhouse gas emissions, including methane from
alimentary tract fermentation and nitrous oxide that may be emitted from decomposing
manure and fertilizer. Indeed ruminants constitute the biggest anthropogenic source of
methane emissions.
If the climate change with increasing global temperatures that we experience today will
continue at the current pace this will have enormous consequences for plant and animal
life, including the human population. A significant rise in the sea-water level is expected
due to melting glaciers and ice caps, combined with an increased frequency in extreme
weather events. The water use for livestock and accompanying feed crop production also
has a dramatic effect on the environment such as a decrease in the fresh water supply,
erosion and subsequent habitat and biodiversity loss. In order to limit temperature
increase to an acceptable level it has been calculated that in 2050 greenhouse gas
emissions need to be between 40 and 80% reduced compared with the levels of 2000.
Land use, including that for the livestock sector, has increased dramatically in the past
decades, leading to loss and fragmentation of habitats. As a result the total area of
habitats important for biodiversity such as rain forests and wetlands has decreased
dramatically. Since the total land area of planet Earth is finite, the land surface that can
be used for the livestock sector either for cropping or grazing is limited. The future
increase in agricultural production will therefore have to stem from intensified agriculture
on land already used, and/or from a more efficient conversion of plant material to edible
meat products.
An additional complication is that, particularly in developed countries, animal welfare has
become a societal issue and keeping animals for consumption is a matter of debate for a
significant part of the population.
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