Building the greenhouse: are we paving the way to climate change?
Even if we somehow magically minimised to zero our carbon emissions from industry, transport and domestic sources, the excess of carbon dioxide in the atmosphere may not be reduced a great deal, and may even continue to increase. Why? Because we are making too many shadows.
Every built structure, be it a road, a house, or even a wooden fence, interacts with incoming solar energy, which arrives mostly as light. In the natural world, light falls on natural surfaces: rocks, water, sand, but most importantly, vegetation. More specifically, the leaves of plants.
Photosynthesis is the most efficient mechanism for absorbing light energy, and converting it to chemical potential energy, that we are aware of. While photovoltaic cells may be capable of utilising more of the visible light spectrum, (plants only use the red and blue wavelengths), and may actually be more efficient at absorbing the light and converting it to a storable form, (electricity), plants still have an advantage: They remove carbon dioxide from the air as they function.
The chemical result of photosynthesis are sugars, an important component of which is carbon. Plants take carbon from the atmosphere, and combine it with hydrogen from water, releasing oxygen in the process. The efficiency of this reaction is, assuming adequate water supplies are available, limited mainly by how much light energy is available. The more light, the higher the rate of photosynthesis, and consequently, the higher the rate at which carbon may be drawn from the air.
Shade from buildings, fences and other human structures prevents light from landing on the photosynthetic surface of plants. Further, paved areas, such as roads and pathways, reduce the available area for plant growth which clearly reduces potential carbon absorption. The other effect they have is to absorb and reflect energy form the sun. Absorbed energy is converted into low level heat, which on a local scale can affaect weather patterns, and change climatic conditions. On a larger scale, the effect is probably less obvious, but reflected energy is trapped by the natural (and enhanced) greenhouse effect, contributing to climate change.
More awareness of these issues in the design and construction of human shelter, communication and transportation necessities is required if a serious and lasting solution to climate change is to be achieved.
Every built structure, be it a road, a house, or even a wooden fence, interacts with incoming solar energy, which arrives mostly as light. In the natural world, light falls on natural surfaces: rocks, water, sand, but most importantly, vegetation. More specifically, the leaves of plants.
Photosynthesis is the most efficient mechanism for absorbing light energy, and converting it to chemical potential energy, that we are aware of. While photovoltaic cells may be capable of utilising more of the visible light spectrum, (plants only use the red and blue wavelengths), and may actually be more efficient at absorbing the light and converting it to a storable form, (electricity), plants still have an advantage: They remove carbon dioxide from the air as they function.
The chemical result of photosynthesis are sugars, an important component of which is carbon. Plants take carbon from the atmosphere, and combine it with hydrogen from water, releasing oxygen in the process. The efficiency of this reaction is, assuming adequate water supplies are available, limited mainly by how much light energy is available. The more light, the higher the rate of photosynthesis, and consequently, the higher the rate at which carbon may be drawn from the air.
Shade from buildings, fences and other human structures prevents light from landing on the photosynthetic surface of plants. Further, paved areas, such as roads and pathways, reduce the available area for plant growth which clearly reduces potential carbon absorption. The other effect they have is to absorb and reflect energy form the sun. Absorbed energy is converted into low level heat, which on a local scale can affaect weather patterns, and change climatic conditions. On a larger scale, the effect is probably less obvious, but reflected energy is trapped by the natural (and enhanced) greenhouse effect, contributing to climate change.
More awareness of these issues in the design and construction of human shelter, communication and transportation necessities is required if a serious and lasting solution to climate change is to be achieved.
posted by The Last Scientician at 6:41 PM
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