Is deforestation a necessary evil? Part 1

Welcome to the last post within this blog (although it has been split into two parts because it is of considerable length). Way back in the realms of early October this blog set out an assortment of slightly related aims: explore the consequences of deforestation; examine whether the effects of deforestation are always bad; explore solutions; look at past patterns of deforestation and examine how complicated the discourse on deforestation is. They have all been examined in one blog post or more and now it is time to draw conclusions and thought from what this blog has researched. The overarching question of this blog, and the title of this post - is deforestation a necessary evil? - shall be finally answered.
This blog post will examine four key areas of interest that have been discussed throughout the blog:

1. The relationship between global environmental change and deforestation. 
2. The relationship between humans and deforestation.
3. Why deforestation is a bad process.
4. Sustainable Deforestation and Is a tree apocalypse inevitable?

Drawing upon references and ideas discussed in other blog posts will bring in an element of repetition but it is ultimately a post to explore my personal opinions towards the topics being discussed, in conjunction with academic research. 

The Relationship between Global Environmental Change and Deforestation

Trees, and vegetation generally, are an integral part of the Earth system involved in various cycles including the hydrological cycle, carbon cycle, nitrogen cycle and countless ecological cycles/systems. 

The importance of trees in the global nitrogen cycle (source)

In terms of carbon, trees act as a major carbon sink taking up carbon dioxide during the process of photosynthesis (Malhi et al. 2008). 150-200 Pg of carbon is stored in the Amazon within biomass and soils (Brienen et al. 2015). This study demonstrated the importance of trees as well as other vegetation and biomass that stores carbon and questioned the future of carbon sinks within the Amazon. 

Deforestation removes this store of carbon and releases it into the atmosphere. It is estimated that 1.8ppm of atmospheric carbon can from deforestation of the Amazon (Exbrayat and Williams 2015). Fueling climate change will have a positive feedback mechanism in which a warmer world causes increased drought (and wildfires) in the tropics leading to the destruction of more forests which in turn release their stored carbon (Haog 2009). 

The effect of deforestation on regional climate is also severe with increased surface temperature (due to reduced albedo) leading to a decrease in evapotranspiration and precipitation. A reduction in cloudiness and increases in insolation creates an increase in high pressure systems and frequent droughts. Furthermore, the alteration of the land surface increases wind speeds and therefore desertification and soil erosion (IPCC 2007; Malhi et al. 2008; Shukla et al. 1990). 

Trees impact on climate and vice versa and are an important factor in influencing global climate - the Amazon is the engine for global atmospheric circulation - and an alteration to this precious system would change our climate. 

The Relationship between Humans and Deforestation

Like the mighty oak, human beings have become an integral part of the Earth system (see their influence in the nitrogen cycle diagram) and have an impact on the climate and landscape more so than any other species. 

The causes of deforestation have been discussed extensively whilst the relationship between urbanization and deforestation in Africa has also been explored. 

The reality is that like oil, food and water, the human population needs trees as a source of fuel (e.g. firewood), shelter and for basic necessities (paper, furniture etc.). It has been at the core of our civilization for thousands of years and the relationship between humans and the threes is as delicate as their relationship with climate. 

I won't drone on about this in much detail with two blog posts already exploring societal collapse on Easter Island and in Mayan Central America but a brief recap won't hurt. There are numerous studies that contribute the collapse of Mayan society to deforestation (Haug et al. 2003; Ogelsby et al. 2010; Shaw 2011). The studies illustrate how important trees are in local climate - influencing drought. However, archaeological evidence and paleoenvironmental evidence is not always complementary and their are disputes as to whether deforestation alone contributed to the collapse of Mayan society (MacNeil et al. 2009). In reality it was probably a combination of socio-economic and political factors exaggerated by detrimental environmental effects such as drought that was caused by over-deforestation. 

I have already suggested that the attitude past societies (such as the Mayans and the Polynesians) had towards deforestation is much the same as our own and that there is potential for us to eventually cut down all the trees. 

A quirky diagram to illustrate MacDonald's arguement (Cool Geography)

Humans need trees (as I have mentioned already) and an article by MacDonald (2012) offers a concise synthesis of the relationship between humans and climate change. He notes that the humble tree is a hindrance to human societal expansion (in terms of space) as well as food production but that without trees mankind could not survive. Trees create an idyllic and comfortable in which human beings can frolic and grow by taking in heat during photosynthesis. He interestingly draws upon the dated works of Thomas Malthus to explore how human populations grow and survive. MacDonald further offers a controversial (yet logical) view point to combating deforestation and climate change saying it is the responsibility of world leaders to keep the world's population in decline in order to ensure a good quality of life for the current population. I think for MacDonald, the root cause of the world's problems is overpopulation (draining resources, taking up space, degrading the landscape and producing pollution). To some extent he is correct but there are definitely alternatives to controlling population and implementing anti-natalist policies. 

It is true that we need trees for survival but I think (and this will be discussed later) we can do more to manage the way in which we use trees. What I want everyone to take from this post (is not the doom and gloom population comments) but that trees are vital in the Earth System and that everything is interlinked. 

The remainder of this posts (questions 3+4) will be explored in "Part 2" but please feel free to comment and vote on the poll in the top left of the screen - it will be interesting to see what everyone thinks. 

Ecology, Soil Erosion and Butterflies - do we exaggerate the consequences of deforestation?

In weighing up the question posed within this blog - is deforestation a necessary evil? - the relative consequences of deforestation must be addressed and explored. the ecological and social effects of deforestation have not been fully examined within this blog and within this post their relative importance will be explored. The environmental and climatic effects of deforestation were discussed in a previous blog post about deforestation and climate change.


Ecology and Soil - are they important?
News articles and websites are extensive in their listing of the effects of deforestation placing prominent emphasis on ecological effects - the loss of plants, birds and microorganisms. With 70% of land species living in forests (National Geographic) it is not surprise that scientists, conservationists and policy makers are concerned with the destruction of the rainforest but why do a few insects and plants matter?

The rainforest is hot and humid, difficult to reach and riddled with insects and is an environment that is difficult to survive in so why would we need it? Butler (2012) offers a similar view that the ecological effects of deforestation are exaggerated and that we should place greater emphasis on our reduced quality of life from an unstable climate and local weather problems. To dismiss the ecological effects of deforestation is a bold stance but it is easy to see where Butler is coming from - surely we should put the quality of human life before animal, insect and plant life?

Academics are quick to emphasis the importance of ecological destruction such as Sodhi et al's (2010) research on Pulau Mengalum, Borneo, which has lost all its closed canopy forest and 40% of its butterfly species. I think a limitation of much of the ecological literature concerned with deforestation such as Sodhi et al.(2010) and Horgan (2005) is that the research isn't directly brought back to the impact a loss of ecology will have on humans. Humans and plants and animals are constantly linked.

The loss of plants and animals is not just an ecological loss but it also has a major impact on the word's poorest communities that rely on forest resources for medicine, food and fuel (Butler 2012; Oglesby et al. 2010). Furthermore, it is not just indigenous communities that depend on the rainforest with 25% of global medicines derived from plants within tropical rainforests (Kirkman 2014). This shows that the rainforest, in ecological terms, is vital for human life.

For many the jungle acts as a valuable resource to sustain their lives (National Geographic)

There is also extensive research into soil erosion, resulting from deforestation, in places such as Bangladesh (Sirajul et al. 2014), Iran (Hajabassi et al. 2014) and the Amazon (Live Science). Unlike the research into ecology, the authors note that soil erosion has a negative impact on the quality of human life causing desertification and the increase in soil enter water resources. It also increases flooding and landslide events. Interestingly, research by Navarette et al. (2015) concluded that the slash and burn approach to deforestation added nutrients to the soil. It built upon the "nutrient rich ash" hypothesis (Nye and Greenland 1960) and suggested ash increased soil pH and added nutrients resulting in soil fertility. Its unusual for a positive effect of deforestation but this benefit is short term and it is assumed the nutrients are washed and leached away.

The ecological and environmental consequences of deforestation are severe but often set aside from the impacts they in turn have on humans. Research into the effects of deforestation must be more holistic if it is to address these consequences by looking at everything.


Society and the forest
The effects of deforestation have been apparent for decades from the alteration of local and global climate (Rotmans and Swart 1991) to rises in temperature (Schultz 2014) and soil erosion. However, the effects deforestation has had on society have occurred over much longer time frames.

"The Last Truffula Tree" - every tree was chopped down and used on Easter Island (Sci News)

Rapid overpopulation leading to deforestation and the removal of every tree on Easter Island has been contributed to the likely collapse of indigenous people on the island (Diamond 2005; Mann et al. 2008). Charcoal records in lake sediments have shown the increase in slash and burn deforestation methods following periods of human colonization on the island (Mann et al. 2008). I would argue that the events that transpired on Easter Island - whether it was human or climate related (this is still up for debate) - that resulted in the total removal of all trees acts as a small scale proxy for what could happen to Earth if deforestation is not combated. The effects of a treeless Earth would me most detrimental to the human population and the species as a whole.

Easter Island is not the only case study many arguing that deforestation caused (or contributed) to the collapse of many Maya settlements (Diamond 2005; Haug et al. 2003; Oglesby et al. 2010). However, often academics have focused on evidence within their own field. Palaeo and archaeological evidence is not always complementary and deforestation was probably a contributing factor to socio-economic and political changes that eventually led to the "collapse" of Maya society.

As mentioned in an earlier post regarding deforestation and Maya civilization, the effect deforestation had on past societies demonstrates how much humans rely on forested land (for fuel etc.) and how important trees are to maintain a desirable environment. Without trees our climate would be harsher, it would be harder to grow crops and our quality of life would be severely reduced.

• Can the collapse of post societies be a prediction of things to come?

This blog post has examined the ecological and societal effects of deforestation and it is clear that the consequences of deforestation are severe - they should be examined, and researched in order to solve them. As population increases, more trees will be cut down and the consequences of deforestation will get worse. 

*Diamond (2005) is only available in book form although there are online summaries available.

Nature's Revenge: Deforestation and the Collapse of Society

It was a rainy afternoon in Starbucks when I searched "deforestation" on Google Scholar and the results were endless. One article by Oglesby and others, whilst not immediately relevant to the content of my blog, posed some burning questions.
In summary, "Collapse of Maya: Could deforestation have contributed?", suggested that the deforestation of trees in the Peten Region of northern Guatemala contributed heavily to the collapse of society in the 9th century. It is an incredibly useful article in understanding the ways in which early societies over-exploited resources at their disposal and the potential outcomes of our current society if they continue to over-exploit the natural world.

Old Relics - Ruins of Maya Society in Guatemala today (fineartamerica)

The science behind the history
Pollen records of the region show that most of the forest had been cut down and in less than a century the population declined by 80%. Deforestation leads to a reduced amount of evapotranspiration from the  land surface causing warming and a high pressure system to develop in the atmosphere. The warmer surface heats the air mass above causing it to rise which leads to a reduction in precipitation and drought (Oglesby et al. 2010)

The collapse of modern society
How resilient is current society to large scale droughts? Could excessive deforestation eventually change climate so much that it is impossible for society to function?

The results of this study can be used for present and future climate and water modelling in Central America as ongoing deforestation is such a problem. However, in an increasingly globalized world it seems unlikely that the whole of society would collapse due to deforestation. Furthermore, politics and international treaties would inevitably prevent such a catastrophe from happening.

Criticisms
This article was an incredibly enjoyable article to read and fascinating however, it is limited to some extent. Whilst it doesn't acknowledge this, it does mention other "theories" that could explain the collapse of the Maya in Peten. In other words, deforestation was not the only factor contributing to their rapid demise but disease, natural disasters, warfare and politics could have all played equally big roles.

Most academics agree that it is a combination of ecological and social factors. The factor that is often given the greatest emphasis (in this case deforestation) is often seen to be the most important because it is a topic in the authors' field of discipline. Historians might be warfare or politics as of considerable importance whilst geographers would argue deforestation or hurricanes were important.


When I started this blog I had a very unclear mind of what the content would be. Semantics of logging, carbon footprints and a decline in ecology were going through my mind. However, this article has demonstrated the importance of often looking to the past for information about current human practices.