Causes of Greenhouse Emissions
Referring to figure 2, the agricultural sector, energy, transport, industry, and industries have a combined 79% of the total greenhouse gas emission. These sectors are, therefore, the major contributors to global warming which results in climate change in various regions.
2.2.2.1 Transport sector
The EPA reports that as of 2017, the transport sector was the largest generator of greenhouse gases in the United States due to activities such as burning fossil fuels in air, land, and sea transport. Other researchers, such as Alzard et al. (2019), also report similar findings, observing that in 2016, the transport sector accounted for at least 25% of the world’s total GHG emissions with 8Gt of CO2 being emitted. The researchers argued that the increased use of petroleum-based products led to the rise in carbon dioxide emission levels due to the carbon released by engines (Hawkins and Dente, 2010). Shaheen and Lipman (2007) report that although the transport sector contributes about 20% of the total anthropogenic greenhouse gas emissions across the globe and 27% in the US, electricity and heat generation account for a greater percentage of the gaseous emissions.