If you choose to delve into the magnificent world of Diaforlife – a realm in which you will find a community of people actively cooperating for the betterment of human (and non-human!) existence – it is likely that you will run into a little something called the Greenhouse Effect. Chances are, actually, that you were directed here from another article, seeking greater understanding of this phenomenon. In any case, below you will find essential information on the subject to help you navigate through Diaforlife’s environment-oriented content – and all other such content for that matter, from the pleas of Green political parties to casual ‘coffee conversations’.
For starters, let it be clear that the Greenhouse Effect is a good thing; it makes our life on Earth possible by maintaining (relatively) warm and stable temperatures. The problem is not the existence of this phenomenon, but the human activities that enhance its effect – hence it is called the Enhanced Greenhouse Effect, which is the cause of Global Warming according to mainstream scientific assessments. Thus, in essence, it is not the world that ought to be changed. It is us.
To understand it let us first look at how an actual greenhouse, a building made of glass in which plants are grown, operates. Sunlight – which in itself is not actually warm – penetrates through the greenhouse’s glass, and then hits plants inside it. When it encounters physical things, like our human skin, (portions of) the sun’s light energy is converted into heat energy which is in part absorbed and in part reflected back towards space. However, in a greenhouse, glass is not as permeable to heat as it is to light; the result is that whilst sunlight can easily come into the greenhouse, the heat energy it generates cannot easily escape from it. As such there is a warmer ambient temperature inside a greenhouse than outside of it, thus helping plants grow when the outside temperature is somewhat cold.
The Earth’s atmosphere, a thin layer of gases which envelopes the planet, functions similarly to a greenhouse. It allows sunlight to pass through it easily, but traps portions of heat energy when the latter attempts to radiate back into space after reflecting off the Earth’s surface. This trapped heat then remains within the Earth’s atmosphere, keeping us (relatively) warm. The gases which perform this task of imprisoning heat are the well-known Greenhouse Gases like carbon dioxide (CO2), methane (CH4) and oxides of nitrogen amongst many others.
That sums up the elementary science of the Greenhouse Effect. Sadly, however, it doesn’t end here.
Since the start of the Industrial Revolution in the mid-18th century, human activity has been causing a rise in atmospheric concentration of Greenhouse Gases – CO2 in particular given the recent development of petroleum into an integral part of life. This implies that the atmosphere’s ability to retain heat has improved, causing a gradual rise in temperature within it. That is Global Warming.
In 1988 the United Nations established the Intergovernmental Panel on Climate Change (IPCC), tasked with the purpose to “assess… information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation” (from ipcc.ch, the Principles Governing IPCC Work). The Panel published its Fourth Assessment Report in 2007 – next one to be issued in 2014 – in which it came to several conclusions, including the following:
- “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level”;
- “Most of the observed increase in global average temperatures since the mid-20th century is very likely [90% chance as per IPCC terminology] due to the observed increase in anthropogenic [meaning human-induced] greenhouse gas concentrations”;
- “At continental, regional and ocean basin scales, numerous long-term changes in climate have been observed. These include changes in arctic temperatures and ice, widespread changes in precipitation amounts, ocean salinity, wind patterns and aspects of extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones”.
Thus Global Warming is a confirmed reality, it is 90% likely to be human-induced and appears to have dreadful effects. In all fairness, nonetheless, it should be noted that a number of scientists worldwide oppose the conclusions of the IPCC – some argue, for instance, that temperature rises are largely caused by natural factors while others claim its effects are not as terrible as projected. Although their views must not go unnoticed, the prevailing human role in Global Warming, the resulting Climate Change, and its detrimental effects are the scientific consensus and should thus be heeded. The Fourth Assessment Report was written by 676 authors and reviewed by 625 experts.
Faced with such overwhelming evidence, we are, as a worldwide community of people, confronted with a choice to make. Should we just ignore it – after all, they’re not 100% sure – and wait for certainty, when matters will be much worse? Or should we accept our individual and collective responsibilities towards ourselves, each other and our future descendants, by making small adjustments to our daily lives and big adjustments to our production methods? In the absence of law, all have to make this choice for themselves. You can guess what we, here at Diaforlife.com, have opted for. And, if you share our view on the matter, you are encouraged to look for ways, here and elsewhere, to reduce your emission of CO2 (and other Greenhouse Gases).
“Little by little, one travels far.”