The current levels of CO2 concentration have risen from approximately 315 PPM to over 390 parts per million (PPM) in 55 years. In the past 450,000 years ago, the highest levels of CO2 concentration were recorded about 325,000 years ago, when it was approximately 295 PPM (Chlumberger Excellence in Educational Development, 2012). This is much lower compared to the current levels of over 390 PPM.
The current level of CO2 concentration is 391.07 PPM as of September 2012. This is a record high compared to the levels in the past 450,000 years ago. The highest it ever got in the past 450,000 years was 295 PPM, and it, therefore, means that the present levels of carbon dioxide concentration are the highest.
Human activities have largely been blamed for the increasing levels of CO2 concentration. Burning of charcoal and fossil fuels is a key cause of carbon dioxide increased concentration. The burning of these elements releases enormous amounts of CO2 into the atmosphere. Livestock keeping is a human activity, which contributes to the high levels of CO2 concentration. Livestock release methane gas into the atmosphere, which is highly concentrated with CO2. During this error of industrialization, the amount of CO2 released by the industries is unbearable.
Plants absorb carbon dioxide from the atmosphere, and, hence when they are cut, there is increased CO2 in the atmosphere. Additionally, when these trees are cut they ultimately end up being converted to forms that release CO2. They are either burnt or are left to rot. This leads to CO2 being released into the atmosphere.
Human beings are the key contributors to global warming. In my opinion, the population is increasing fast, and humans are encroaching forests, cutting down trees, in search of land build homes and farm. The process of industrialization, not to mention the automobile industry, largely contributes to global warming.