Causes of Global Warming

Global Warming

Greenhouse Effect (Image Source: The Intergovernmental Panel on Climate Change)
As already explained in the earlier post, global warming is a product of increased levels of greenhouse gases in the atmosphere which serve to trap/absorb heat from the sun, preventing the heat from escaping into the outer space thereby resulting in increasing global temperature. This process is what is referred to as Greenhouse Effect and the gases that contribute to it are called greenhouse gases which include water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3).

According to Intergovernmental Panel on Climate Change, human activities that contribute to the emission of these gases into the atmosphere are the major causes of global warming. These activities include burning of fossil fuels, cutting down of rainforests, mining, commercial agriculture, and farming livestock.

Burning of Fossil Fuels

Industrial Emission (Image source:Natural Resources Defense Council 

Burning of fossil fuels is one of the major causes of greenhouse gases emissions. While fossil fuels such coal, oil, and gas supply about 80 percent of the world’s energy, when they are burned, they release gases such as carbon dioxide and nitrous oxide. These gases escape into the atmosphere where they accumulate and form a blanket around the planet thereby resulting in greenhouse effect. Some of the activities that involve burning of fossil fuels include driving vehicles, ships, boats, motorcycles, and operating heavy industrial machineries. Christopher Nunez (2019) of National Geographic reports that Carbon dioxide emissions from burning of fossil fuels account for 44 percent of the world total, and it's the biggest single source of the global temperature increase above pre-industrial levels. Carbon Brief, a UK-based website covering the latest developments in climate science, climate policy, and energy policy, on the other hand notes that despite calls to reduce use of fossil fuels, CO2 emissions from fossil fuels and industry grew by 2.7% in 2018; this was the largest increase in seven years. Worryingly, it is expected that 2019 is also likely to record an increase in CO2 emissions.

Cutting Down of Rainforests

Deforestation (Image Source:www.industrytap.com/)

            Trees are very important in keeping the level of carbon dioxide in the atmosphere at natural levels thanks to the fact that they take in CO2 and release oxygen into the atmosphere. Tropical rainforests are very vital in this process because of their large sizes which serve to increase the amount of C02 they take out of the atmosphere. However, when these forests are cut down, large amounts of CO2 build up in the atmosphere as there are fewer trees taking it out. Burning of these trees and forests also releases carbon dioxide that were stored in the trees into the atmosphere. The end results of these activities are increase in carbon emission and consequently, global warming. Many tropical forests are being cleared for various reasons including beef production, crop farming, urban expansion, and settlement. Deforestation is thus a major issue that must be effectively addressed. According to National Geographic between 1990 and 2016, the world lost 502,000 square miles (1.3 million square kilometers) of forest, while 17 percent of the Amazonian rainforest has been destroyed over the past 50 years.

Commercial Agriculture

Livestock farming (Image Source: weebly.com)

Commercial agriculture or farming of crops and animals is also a major cause of global warming because of the greenhouse gases that they release into the atmosphere. According to European Environment Agency, farming in particular releases significant amounts of methane and nitrous oxide, two powerful greenhouse gases. 

(Image Source: https://ccafs.cgiar.org/)

Methane is produced by livestock during digestion due to enteric fermentation and is released via belches. Methane can also escape from stored manure and organic waste in landfills. Nitrous oxide emissions on the other hand are an indirect product of organic and mineral nitrogen fertilizers. Commercial agriculture is carried out in large scales thereby increasing significance of greenhouse gases emitted into the atmosphere. Besides greenhouse gas emission, commercial agriculture has also significantly contributed to destruction of tropical forests leading to increased accumulation of CO2 in the atmosphere and consequently accelerating the rate of global warming.

Other Activities

            There are also minor activities that contributes to greenhouse emissions. These activities include use of products such as air fresheners, perfumes, and vacuum cleaners which contain chlorofluorocarbons. Other activities such as burning of plastic wastes also release CO2 into the atmosphere thereby contributing to the problem of global warming.

            In order to effectively address the problem of global warming, we must thus find ways to reduce emission of greenhouse gases. This will entail moving away from use of fossil fuels and adapting green energy sources, limiting cutting down of forests and planting of more trees, and reducing commercial farming and use of fertilizers in agriculture. We must also stop usage of products that contain chlorofluorocarbons and ban usage of plastics.

Sources

European Commission. “Causes of climate change.” Available at             https://ec.europa.eu/clima/change/causes_en

European Environment Agency. “Agriculture and climate change.” June 30, 2015. Available at https://www.eea.europa.eu/signals/signals-2015/articles/agriculture-and-climate-change.    Accessed December 23, 2019

Intergovernmental Panel on Climate Change. Fifth Assessment Report, 2014. Available at             http://ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_SPM.pdf

Nunez, C. (2019). “Deforestation explained.” National Geographic. Available at                 https://www.nationalgeographic.com/environment/global-warming/deforestation/

Nunez, C. (2019). “Fossil fuels, explained.” National Geographic. Available at             https://www.nationalgeographic.com/environment/energy/reference/fossil-fuels/