18th Century, the burning of fossil fuels has wreaked havoc on the atmosphere and environment. Today, carbon dioxide levels are higher than they have been in the last 750,000 years[sc:1]. Such a drastic increase in only 200 years means that these atmospheric changes are undeniably attributable to climate change.
The manufacture of cement is a little-known contributor to greenhouse gas emissions. When the calcium carbonate is heated in the manufacture process, is released CO2 into the atmosphere[sc:2]. In fact, the cement industry accounts for about 5% of all greenhouse gas emissions[sc:3]. Considering that vital infrastructure such as roads, buildings and building foundations are made of cement, its production is vital to society. Because of this, it is difficult to imagine a way in which we could cut down on greenhouse gas emissions stemming from cement manufacture.
With the human demand for animal meat ever increasing, the advent of intensive animal farming has led to enormous greenhouse gas emissions. The sheer number of animals being farmed intensively at one time means that a huge amount of resources is used to grow them, and a huge amount of waste is produced. At any one time, there are roughly 65 billion animals alive in intensive animal farms worldwide[sc:4]. Many people don’t want to acknowledge the impact of animal farming on the environment. In fact, in Al Gore’s documentary An Inconvenient Truth, there was no mention of animal farming as a contributor to global warming. The denial of agriculture’s contribution is outrageous, especially considering that intensive farming contributes more to climate change than all the world’s planes, trains and cars combined[sc:5].
Another heavyweight in the greenhouse gas equation is transportation. This is a well-known and readily acknowledged contributor to the climate change problem. Vehicles produce carbon dioxide, but also nitrous oxide and methane[sc:6]. In the US, vehicle emissions make up a whopping 1/5th of all US emissions[sc:7]. That figure is made up of the emissions caused in in the extraction, production and delivery of fuel, as well as the fumes that come directly from the car’s exhaust. Whilst transport is clearly a major contributor to greenhouse gas emissions, there has been significant investment and research into alternatives. Electric cars are slowly becoming more commonplace. What’s more, people are taking steps to reduce their greenhouse gas emissions by even choosing to go car free, especially in major cities with good public transport.
Aerosols have a cooling effect on the climate, and therefore have masked some of the impact of greenhouse gas emissions on global warming[sc:8]. Without aerosols, the warming of the planet would be even more extreme. Aerosols are damaging to human health, and for this reason there has been an effort to reduce their release into the air. However, because of the lessening of aerosol use, the masking effect of aerosols is soon to wear off, meaning that global warming will most likely accelerate as a result[sc:9].
Evidently there are several anthropogenic sources of greenhouse gas emissions. Some have more of an impact than others, but all must be addressed if humanity has any hope of living on a habitable Earth going into the next century.