The 21st Century Challenges To Civil Engineering Environmental Sciences Essay

Throughout the centuries, human society has followed an adventurous, uphill, but fruitful course of development. During this course, one of the most useful – and used – tools in the service of human communities has been civil engineering, along with architecture, which goes hand in hand with. Conducting, designing, creating, innovating, achieving great works in infrastructure and construction of buildings, it has turned out to be a “civilization machine” [1] . It has, literally and metaphorically, constructed the background of each and every human civilization that has appeared and evolved on earth. Greeks, Romans, Egyptians, Babylonians, Chinese, and so many others along the human history, have prevailed for long on their grounds and the surrounding areas due to the not only impressive but also useful structures they achieved in creating – thus giving a boost in the progress of their civilizations.

Nevertheless, there have been mistakes and blunders, especially during and after the era of industrial revolution up to nowadays, which have led to a severe degradation of our planet. Today, taking a look at the condition of the air, the waters and the soil, the degree to which they have been polluted, and the suffocating residential areas which have been created, we cannot help being stunned at how this tool has been transformed into a weapon against ourselves. Since it is quite unrealistic to consider every field of human activity as independently operating, because each one of them interlaces with the others and the environment as well, it is obvious that the creations of civil engineering have their impact not only on people, but on the rest of the ecosystems as well. Therefore, a conscientious evaluation of this impact should be conducted before proceeding in future action, as the environmental problems are severe and eminently present.

The twenty-first century holds a variety of new challenges for civil engineering, and calls for methodical handling and effective designing, or re-designing, every capacity in human living. “Society has a blind spot for its basic needs, preferring instead to focus on glamorous developments. Problems that result from this thinking involve housing the population, addressing decaying urban infrastructure, maintaining the environment, dealing with natural disasters and climate changes, and transporting people and goods. Sustainability of the environment and society will be paramount issues” [2] .

“The majority of Europeans live in an urban environment and billions of euros are spent every year on building projects in the EU towns and cities” [3] . “Expenditure generally bears some level of proportional relationship with environmental impact. Expensive building components often have more processing involved and so they usually have higher embodied impacts per tonne than cheaper raw materials.[…] For example, roads are the biggest expenditure under the infrastructure heading. By introducing efficiencies in delivery networks, green transport solutions and reducing the need to travel, then the demand for new roads could in the long term be reduced. As another example, the largest impact area under the non-residential category is new offices, yet there are thousands of offices sitting vacant at present. Perhaps regional planning strategies could maximise the use of existing vacant offices before allowing the building of new ones. According to the Urban Task Force report, there are some 4,500 hectares of land occupied by vacant commercial buildings. These provide the opportunity to either reduce the need for new commercial buildings, or they can be converted into 95,000 new residential dwellings with very low environmental impact investment. In addition, there are around 753,000 vacant residential dwellings in the UK. This represents 3.9% of the housing stock. The Urban Task Force report suggests that some 150,000 of these could reasonably and economically be used to provide good-quality desirable homes. Refurbishing existing stock instead of building new will save more materials and haulage than any recycling or reclamation solutions. Where possible, this should be a preferred redevelopment approach” [4] .

Construction materials are a major factor contributing to the significant impact which construction imposes on the environment. It is pointed out that “19% of the UK eco-footprint is taken up by the embodied environmental impact of built infrastructure. This includes homes, offices, factories, roads, airports, railways, water treatment works, power stations, retail complexes etc. Every year materials are used to construct these facilities and it is the embodied environmental impacts of these materials – raw material extraction, processing, manufacture, haulage, packaging – that make up this section of our collective eco-footprint.” [5] “Quarry products including stone, crushed rock, aggregate and sand make up between 51% and 62% of the resource flow. Cement and concrete products such as ready mix and concrete blocks are the next largest group making up 20-40% of the resource flow. Bricks, metals, glass and timber products each make up between 1% and 8% depending which data source is used.[…] All three sources show high impacts from cement (14%, 18% and 40%) and ready made concrete (16% and 10%). Other categories that are significant are quarry products (7%, 2% and 22%), metals (22% and 2%), glass (5% and 16%), timber products (5% and 17%), bricks and blocks (16% and 5%). Plastics are only reported in the DTI statistics but are significant in their embodied CO2 at 7%” [6] .

Apparently, the call for applied sustainable development is more urgent than ever. “Harnessing the principles of sustainability in the construction industry will help Europe create and manage a more healthy built-environment. It should mean resources are used more efficiently, and that decisions can be made based on ecological principles. Introducing sustainability into the workings of the construction industry must take account of a variety of factors, not just how ‘bricks-and-mortar’ products are made and used. Wider environmental, quality of life, economic, institutional and social issues also have to be addressed” [7] .

But, let us first define the terms “sustainability” and “sustainable development”, so that we can coordinate their principles with the ones of civil engineering and construction practice. “Sustainability is a relationship, or balancing act, between many factors (social, environmental and economic realities and constraints) which are constantly changing” [8] . “Sustainable development is the process by which we move towards sustainability. Sustainable development focuses on improving the quality of life for all without increasing the use of natural resources beyond the capacity of the environment to supply them indefinitely. Sustainable development is not a new idea. Many cultures over the course of human history have recognized the need for harmony between the environment, society &

economy. What is relatively new is the articulation of these ideas, based on science, in the context of a global industrial information society” [9] .

“While traditional design and construction focuses on cost, performance and quality objectives, sustainable design and construction adds to these criteria minimization of resource depletion and environmental degradation, and creating a healthy built environment (Kibert 1994). Sustainable designers and constructors will approach each project with the entire life cycle of the facility in mind, not just the initial capital investment. Instead of thinking of the built environment as an object separate from the natural environment, it should be viewed as part of the flow and exchange of matter and energy which occurs naturally within the biosphere. […] Built facilities impact the natural environment in many ways over their entire life cycles. Yeang (1995) lists four categories of impacts which built facilities have on the earth’s ecological systems and resources:

• Spatial displacement of natural ecosystems, and modification of surrounding

ecosystems as a result

• Impacts resulting by human use of the built environment, and the tendency for

that use to spur further human development of the surrounding ecosystems

• Depletion of matter and energy resources from natural ecosystems during the

construction and use of the facility

• Generation of large amounts of waste output over the whole life cycle of the

facility, which is deposited in and must be absorbed by natural ecosystems.

Given their large scale and long life cycles, built facilities have particularly large and long-lasting effects on the environment as a whole. The following strategies are examples of approaches which can be taken to improve the sustainability of built facilities by avoiding negative environmental impacts over their life cycle” [10] .

Recovering Waste: Reduce, Reuse, Recycle.

Reusing Existing Development.

Integrating the Built Environment into Ecological Systems.

Taking the life cycle of a structure under consideration during the design and construction processes is particularly important, because it involves more than just constructing the structure itself. How a facility operates, is maintained and finally disposed are matters that also consume materials and energy, and are widely predominated by the design

and construction decisions made in the early phases of its life cycle. Since modifications are easier to make during the design of the facility, and the costs of the changes

are lower when the facility still exists only “on paper” instead of being a concluded tangible structure, the major attention should be paid at the very beginning. “This way, the primary

responsibility for creating sustainable built facilities falls to the designers and constructors of such facilities. People who make project decisions with sustainability as an objective will need to evaluate the long-term as well as short-term impacts of those decisions to the local and global environments.” [11] .

“In the creation of built facilities, there are many opportunities to improve how

design and construction are currently done to make them more sustainable. Three general

objectives should shape the implementation of sustainable design and construction, while

keeping in mind the three categories of sustainability issues discussed above (social,

environmental, and economics). These objectives are:

• Minimizing consumption of matter and energy over the whole life cycle of

consumption, while

• Satisfying human needs and aspirations with sensitivity to cultural context, and

• Avoiding negative environmental impact.

In the following subsections, we present specific strategies for approaching each of the

three objectives, along with examples of technologies and opportunities related to each of

the strategies” [12] :

Minimizing Consumption

Improving Technological Efficiency: Doing more with less.

Reuse, Rehabilitation, and Retrofitting.

Creating New Technologies.

Modifying Historical Technologies.

Reshaping Human Desires.

Satisfying Human Needs and Aspirations

Improving Economic Viability.

Matching User Needs with Facility Design.

Creating a Healthy Built Environment.

Empowering People to Meet their Own Needs.

Avoiding Negative Environmental Impacts

At times, there have been people who have reminded us that the engineer’s role goes beyond

that of the executor of narrow technologies: As Donald Schön had written some years ago:

“In the varied topography of professional practice, there is a high, hard ground overlooking a swamp. On the high ground, manageable problems lend themselves to solution through the application of research-based theory and technique. In the swampy lowland, messy, confusing problems defy technical solution. The irony of this situation is that the problems of the high ground tend to be relatively unimportant to individuals or society at large, however great their technical interest may be; while in the swamp lie the problems of greatest human concern.

The practitioner must choose. Shall s/he remain on the high ground where s/he can solve relatively unimportant problems according to prevailing standards or rigour, or shall s/he descend to the swamp of important problems and non-rigorous inquiry?” [13] 

Regarding the vastness, multiplicity and depth of sustainability matters in the field of civil engineering, we could attribute the term “messy problem in the swamp” to it, as a profoundly corresponding image. However, as sustainability is meant to occupy a central and quite broad region in the civil engineering and engineering curriculum, a rigorous inquiry will have to escort all the current construction practices and their renewal – wherever this is necessary.