A plant's eye view

Dear readers,

Today I'd like to share a video with you that I found truly inspiring. As I'm sure you've gathered from some of my previous posts here at PP&P, I've always felt a strong connection with nature. Since moving to London and being relatively far away from my beloved Canadian wilderness, I find that sometimes I forget that we are part of a bigger thing: the biosphere. Listening to Michael Pollan talk about looking at the world from a "plant's eye view" really put things back into perspective for me on this grey British afternoon.

Two aspects of this talk particularly struck me. First, the notion that plants manipulate the animal species which rely on them for survival. Pollan (2008) argues that humans are lured and manipulated by plants just as a bee is lured by a colourful and sweet-scented flower blossom, allowing it to spread its genes while the bee gathers nectar from flower to flower. This example is extended to agriculture, with the suggestion that this technique of mass producing food arose as a "co-evolutionary development" in which edible grasses have and continue to exploit humans. Now that's something to think about!

The second most impressive aspect of his talk was his personal account of Joe Salatin's organic farm (Polyface Farms), in Shenandoah Valley, Virginia. Pollan (2008) describes this organic farm which symbiotically raises over five species of animals as well as some forestry products on a mere 100 hectares of land. What is unique about this farm is that it produces vast amount of food products by simply harnessing the desires of each species involved. In this way, the species perform a variety of ecological services for one another. For example, cows on this farm intensively graze fields. After the grazing is complete, Salatin waits three days before introducing chickens to the same fields. This way, the soils are rich with mature grubs for the chickens to feast on. These chickens fertilise and churn the soil, and remove the grubs, allowing for a quick regeneration of the grasses. Each species involved fulfills a specific purpose. 

To conclude his talk, Pollan (2008) leaves his audience with the idea that this form of food production completely contradicts the pre-conceived notion that nature must be diminished in order for humans to obtain their needs in resources. What would happen if we had a food production revolution, in which all farmers harnessed the desires of the species they harvest? I think the world could be a very different place!

What are your thoughts on looking at the world from a "plant's eye view"? Have you ever tried looking at the world in this way? Do you think a revolution in symbiotic food production could change the way we grow food in the future?

Thanks for reading! 

Case Study: the Aral Sea

Today's post on the Aral Sea slightly deviates from the topic of food, but because it is one of the most catastrophic examples of the environmental impacts of intensive agriculture, I thought it deserved a place on this blog. So let's begin...

Abandoned boats scattered across desiccated areas
of the Aral Sea (Photo by Audun Kjørstad)

The Aral Sea, a large saltwater lake shared between Kazakhstan to the north and Uzbekistan to the south, was once the world's fourth largest body of inland water behind the Caspian Sea, Lake Superior, and Lake Victoria (Micklin, 1988). The Aral Sea drainage basin covers 1.8 million km² within seven nations, and is a terminal lake, i.e. it has surface inflow but no outflow (Micklin, 2006). It has experienced dramatic desiccation during the 20th century as a result of the diversion of riverine waters for agricultural irrigation from the Syr Dar'ya and the Amu Dar'ya starting in the 1960's. The Syr Dar'ya and the Amu Dar'ya are the main sources of water to the Aral Sea, and by the 1980's, these two rivers virtually dried up (Encyclopaedia Britannica, 2014).

The Aral Sea basin (Micklin, 2006)

Until 1960, the Aral Sea was a brackish lake (mean salinity of 10 g/L) that was inhabited by freshwater species. It supported a major fishery and was also used as a regional transportation route. In addition, the deltas of the Amu Dar'ya and the Syr Dar'ya supported rich bioligical diversity as well as activities such as irrigated agriculture and animal husbandry, among others (Micklin, 2006). It is interesting to note that the Aral Sea has been repeatedly flooded and desiccated throughout the Pliocene, the most recent replenishment occurring during the Pleistocene around 140,000 years ago. Over the past 10,000 years, fluctuations in the Aral Sea's surface level ranged from 20 to 40m as suggested by evidence such as marine fossils, archaeological sites and the like (Micklin, 1988).

Average annual water balance for the Aral Sea between
1911 and 2005 (Micklin, 2006)

What happened in 1960 that prompted the Aral Sea's tipping point? In the early days of the Soviet Union, communist authorities devised plans to increase the production of cotton, or white gold. Cotton production was increased in the 1920's, and by 1950 hundreds of kilometers of unlined canals from the Amu Dar'ya and Syr Dar'ya were carved into the surrounding desert to irrigate new cotton plantations (Stone, 1999). The effects of the rerouting of the two rivers were immediately felt, with major water deficits occurring by the 1980's, as can be seen from the above figure. Since 1960, the profile of the Aral Sea has been drastically modified due to this irrigation. Between 1987 and 1989, it was split into a "Small Aral Sea" in the north and a "Large Aral Sea" in the south. By 2005, the Large Aral Sea had become separated into three distinct bodies (Micklin, 2006).

Changes in the profile of the Aral Sea (Micklin, 2006)

So, why is all this important? The desiccation of the Aral Sea led to environmental impacts such as the loss of wetlands as a result of reduced river flow and the loss of fish species due to breeding ground destruction and increased salinity (Micklin, 2008). In terms of human impacts, the disappearance of the inland sea prompted the collapse of local fisheries, the end of shipping routes, and the exposure of a seabed rich in salt, pesticides, and other agricultural contaminants which can be transported by toxic dust storms (Micklin, 2008; Stone, 1999). Vozrozhdeniya (Resurrection) Island in the centre of the Aral Sea was once used as a ground for biological weapons testing. In 2001, the island was joined to mainland, creating a risk of human exposure to these weaponised organisms (Micklin, 2008). 

Resurrection Island (Micklin, 2008)

What's been done to alleviate the situation? In the 1990's, Kazakhstan attempted to restore the Large Aral Sea by constructing a dike to block outflow to the south, which was destroyed by a catastrophic failure in 1999. In 2005, however, a 13km earthen dike with a gated concrete dam for water discharge was installed with the aid of funding from the World Bank. This has led to an 18 percent increase in area of the northern portion of the Aral Sea, and fish are now being caught again in the area (Micklin, 2008). The Aral Sea has shown signs of restoration since then (e.g. Pala, 2011), and time will tell if the southern portion of the sea will one day reappear.

To conclude this post, I'm leaving you with this video of Bruce Pengra explaining how Landsat imagery has been used to document the Aral Sea's decline through time. It's truly amazing to see how the lake has transformed throughout the years. The disappearance of the Aral Sea is undoubtedly one of the great examples of global environmental change through time, and has taught humanity lessons on the effects of over-exploitation of natural resources from delicate ecosystems.

Thanks for reading!

Are Humans Becoming More Carnivorous? Environmental Impacts

In the previous post, we examined a new study by Bonhommeau et al. (2013) which revealed that global meat consumption has increased over the past five decades. How does an increase in meat consumption affect the environment?

Cows (photo from Living Green Magazine)

The livestock sector lies within the top two or three of the most important contributors to environmental issues, both locally and globally. Despite not being a major global economic player, the livestock sector is beneficial and crucial to society, employing and feeding growing global populations (Steinfeld et al., 2006; Herrero et al., 2009). Livestock agriculture contributes to environmental problems such as land degradation, land use change, climate change and greenhouse gas emissions, water shortage and pollution, nutrient excretion, loss of biodiversity, and competition for human food (Steinfeld et al., 2006; Janzen, 2011). These environmental impacts are driven by growing stresses on global human populations, namely the those of food, water, and energy security, biogeochemical interferences, and habitat (Janzen, 2011).

Let's now examine some of these impacts in a bit more detail. Many of the other impacts mentioned above will be the topics of future posts.

Land Use Change and Degradation

Land use refers to the ways in which land is used for human means. It is "characterised by the arrangements, activities and inputs that people undertake in a certain land cover type to produce change, or maintain it" (FAO, 2013). Land degradation refers to the reduction of resources as a result of processes which act on the land, including soil erosion, deterioration of the properties of the soil, and loss of natural vegetation (Steinfeld et al., 2006).

Deforestation for agriculture in Brazil's Pantanal wetland 
(from JNCC, 2013)

Livestock now represents the largest portion of human land use forms, affecting ecosystems around the world (Janzen, 2011). An example of environmental problems brought on by land use change for agriculture is the degradation of tropical rainforests, such as the Amazon. Two main phenomena are related to deforestation as a result of intensive raising of livestock, the first being the direct conversion of forest to pasture land and the second being the clearing of forest for crop growth to feed livestock (Herrero et al., 2009). Approximately 20-30% of the Earth's land surfaces are used for grazing, while approximately one third of cultivated land area is used to feed livestock (Janzen, 2011). 

GHG Emissions & Climate Change

Climate change is possibly the most pressing environmental challenge that has faced the planet. According to the IPCC (2013), the main authority on climate change, the "warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia". This warming can be seen in the atmosphere, the ocean, the cryosphere, in sea level, and in carbon and biogeochemical cycles. The largest contributor to total radiative forcing is caused by the increases in anthropogenic GHGs, such as CO2, since 1750.

Disintegrating iceberg near West Greenland
(from The Guardian)

Animal agriculture produces GHG emissions in the form of CH4 from enteric fermentation, N2O from fertiliser use, CH4 and N2O from manure management practices, and CO2 from from fossil fuel and energy use (O'Mara, 2011) and land use and its changes (Herrero et al., 2009). Livestock induced emissions account for 2.4 billion tonnes of CO2 per year, and on a life cycle analysis basis, they contribute up to 18% of global GHG emissions (Steinfeld et al., 2006). 

Water Shortage and Pollution

Water is essential for life. Only 3% of the water on Earth is fresh, and surface water only accounts for 0.3% of the total amount of freshwater (this includes lakes, rivers, and streams). Another 68.7% of all freshwater is locked away in glaciers, while 30% of freshwater is located within the pores of the ground in the form of groundwater (US EPA, 2013). Approximately 64% of the world's population is expected to live in water-stressed basins by 2025 (Steinfeld et al., 2006).

Water shortage in China (photo from The Guardian)

Freshwater is extensively used in livestock agriculture, the most significant use coming from the irrigation of crops for intensive feeding operations. The livestock sector is a key player in increasing water use and represents 8% of global human water use (Steinfeld et al., 2006). For instance, approximately 16,000L of water are needed to produce 1kg of beef (Janzen, 2011). In terms of water pollution, the major sources from the livestock sector include animal waste, antibiotics and hormones, chemicals from tanneries, fertilisers and pesticides for feedcrops, and sediments from eroded pastures. These pollutants contribute to freshwater eutrophication, coastal dead zones, and the degradation of coral reefs, among others (Steinfeld et al., 2006).

As I mentioned above, these are only some of the many environmental impacts of livestock agriculture. Livestock's Long Shadow by Steinfeld et al. is currently the most comprehensive study on the environmental impacts of the livestock sector. I strongly recommend flipping through it if you're eager to learn more on the topic.

Having read about some of the environmental impacts arising from the livestock sector, what do you think are potential solutions for a more sustainable food industry? 

Thanks for reading!

Environmental Impacts of the Rise of Agriculture

An event as important as the Neolithic Revolution (Bar Yosef, 1998) is one that most certainly leaves a mark. This mark can still be seen today, as the food system many modern human populations rely on continues to revolve around agriculture. The event has been so pivotal, progressivists argue, that it has allowed early human populations to spend less time hunting and gathering, and more time innovating (Diamond, 1987). Were it not for the Neolithic Revolution, would I still be blogging here today? 

An event so monumental for human populations must also have had impacts on the surrounding biotic communities. Zeder (2008) examined the environmental impacts of Neolithic economies in the Mediterranean Basin, which were most important in the large islands of the region. In these locations, domesticated and wild mainland fauna replaced endemic fauna. In Cyprus, for instance, only five endemic species existed before the arrival of humans, namely the pigmy hippopotamus, the pygmy elephant, the genet, and a mouse (Smithsonian Institution, 2013), all of which are now extinct. Zeder (2008) argues that despite the role of humans in the extirpation of endemic island fauna still being unclear due to a lack of definitive evidence, the progressive east-to-west disappearance of these mammals occurring around the time of human colonisation suggests that humans did play a significant role.

Pygmy hippopotamus skull ca. 10,000–8,500 BCE from Aetokremmos
(Smithsonian National Museum of Natural History)

The environmental impacts of the rise of agriculture have also been studied in the other major centres of domestication. Zhou et al., (2011), for example, have shown that an agricultural transition occurred in the Longdong area of China during the Neolithic period. This transition was marked by a shift in early agriculture from producing common millet exclusively to producing other grains including foxtail millet, rice, and soybeans in addition to the common millet. Agricultural civilisations grew rapidly during this period and this expansion altered the Longdong basin ecosystem. Pollen analysis revealed that the predominant effects of the intensification of agriculture in the region were the degradation and simplification of local shrub-grasslands and the expansion of Graminaceae farmlands. Following the abandonment of settlements and agriculture in this location, the ecosystem recovered.

The studies described above are only two of the many examples of the environmental impacts of early agriculture. They highlight that even the earliest agricultural civilisations managed to alter the natural environment, just as we do today albeit at a much larger scale.