Tuesday, 25 October 2011

Join the Neolithic Revolution

Just found this and it pretty much sums up what I said in the last post. I especially like the disclaimer - bottom right. 

The Origins of Agriculture

It has been argued that agriculture was one of the first human impacts on the environment. Agriculture is defined as the cultivation of domesticated plants and animals for use by human societies. Domestication is a genetic selection process exerted (consciously or unconsciously) by humans to adapt wild plants and animals to cultivation and herding, respectively (Gepts and Papa, 2002). Evidence of domestication of plants and animals suggest that it began over 10,000 years ago, during the Neolithic revolution. However, there is great debate about when and why this actually occurred.

This video highlights some of the evidence for the timing and cause of the switch from hunter-gatherers to agriculture.



I think this video nicely highlights the transition to humans taking control of nature.

At the end of the last ice age, approximately 14,500 years ago the climate warmed suddenly (Bølling-Allerød) and new areas of forests grew providing olives, pistachio and nuts etc. these were particularly dominant in the Fertile Crescent area. This enabled Natufian populations to build communities there and become sedentary.

Bar-Yosef among other experts believe a sudden cooling during this period (Younger Dryas) forced Natufians to begin domesticating to maintain food supplies as the forests and wild cereals were becoming more sparse. Archaeological evidence suggests that agriculture evolved separately in many areas of the world at similar times, this indicates that climate was a very important factor. This was the leading paradigm for agricultural origins until recently (Balter, 2010).

The strongest evidence of domestication is the presence of plump rye seeds in Abu Hureyra, Syria, some 13,000 years ago. It was assumed that this indicated human selection of larger grains. However it has been argued that this is not enough evidence to prove that humans actually domesticated the seeds and therefore cannot be used to date the start of agriculture. Recent research has revealed that 90% of 12,000 preserved plant fragments newly discovered in Syria were pistachio and almond remains which gave no signs that the Natufians actually cultivated plants in the area (Balter, 2010).

Some archeologists believe that agriculture did not begin until the Holocene when warm, moist conditions were restored 11,600 years ago, suggesting that people were “pushed” into agriculture by growing sedentary populations and “pulled” by the increased rainfall and more favorable climates (Balter, 2010)

Despite the debates on when agriculture actually started, once it had become established, a rise in population was inevitable surplus food was available and children were seen as useful labor (Gepts and Papa, 2002). It enabled the growth of sedentary, complex societies and even the creation of towns and cities, which resulted in rapid modification of the environment.

The expansion of agriculture was mainly dependent on the environment as much of the growth was during the early Holocene monsoon rains (Gupta, 2004). Therefore the human impact on the environment was kept within environmental constraints. The energy available to grow crops was derived from the sun through photosynthesis. This set a limit to the amount of food that could be produced at any time as solar energy has a limited rate of flow into the planet. This also placed a limit on the population growth, as to produce more food more land had to be cultivated (Pfeifer, 2004). However, this was all about to change as the growth of agriculture marked a time when man became more aware of the value of nature and its usefulness. 

Balter, M. (2010), The Tangled Roots of Agriculture, Science, 327, 404-406 
Gepts, P. and R. Papa (2002), Evolution during Domestication, Encyclopedia of Life Sciences, 1-7
Gupta, A.K. (2004), Origins of Agriculture and Domestication of Plants and Animals linked to early Holocene Climate Amelioration, Current Science, 87, 10, 54-59
Pfeifer, D.A. (2004), Eating Fossil Fuels,  From The Wilderness Publications

Sunday, 16 October 2011

The Environmental Impacts of Agriculture



With the recent growth of environmental awareness, many of us are conscious of our actions and decisions in everyday life and how they may contribute to our personal impact on our environment. Food is something we all require to live and somewhat take for granted. Few of us really think about the impact the production of our food might be having on our environment.

It has been argued that agriculture is one of the first human impacts on the earth. Agriculture is defined as the cultivation of domesticated plants and animals for use by human societies. Evidence of domestication of plants and animals suggests that it began over 10,000 years ago. This marks the time when mankind’s relationship with nature changed as the value and usefulness of nature was realised.

Agriculture enabled human population growth and since it has intensified, mechanised and revolutionised the population has been allowed to continue its uncontrollable growth. But not without having detrimental effects on the environment.

The intensification of agriculture has caused the production of food to move from using solar energy to using energy derived from fossil fuels. The green revolution was made possible by fossil fuel based fertilizers and pesticides and hydrocarbon fueled irrigation. The mechanisation of agriculture meant fossil fuels provided energy for agriculture rather than solar derived human energy and massively increased the rate at which resources were sucked from the earth.

As the population increases further, the amount of fossil fuels we are ‘eating’ increases. The non-renewable nature of fossil fuels makes this highly unsustainable and global food insecurity is increasing as a result. Intensive agriculture is effectively draining the earth of so many of its natural resources.

Throughout this blog I hope to highlight the impacts of agriculture and assess its sustainability and potential to support future population growth. Has the human population reached the earths carrying capacity? Or was that breached a long time ago, thanks to the green revolution? Can further technical innovation solve the problem of our diminishing natural resources? 




Gupta, A.K. (2004) Origins of agriculture and domestication of plants and animals linked to early Holocene climate amelioration, current science, 87,10,54-59
Pfeifer, D.A. (2004) Eating Fossil Fuels,  From The Wilderness Publications