United Nations Framework Convention on Climate Change (UNFCCC) defines climate change as a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. Greenhouse gases (GHG) are the atmospheric gases responsible for causing global warming and climate change by trapping heat within the Earth’s atmosphere. The major GHGs include carbon dioxide, methane, nitrogen oxides, and fluorinated gases, such as hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. Climate change is one of the great challenges of current society. In the last few decades, there has come more evidence that the emission of greenhouse gas contributes to the effect of global warming, particularly the emission of carbon-dioxide (CO2). Within the transport sector, the greenhouse gas emissions are dominated by the CO2 emissions from burning fossil fuels, which are strongly related to transport energy use. Transport is currently responsible for 23% of GHG and 27% of global carbon dioxide emissions. Several repercussions will occur if nothing is done to mitigate climate change, such as
- Heavier and more frequent precipitation and flooding
- Less snow and ice
- Thawing permafrost
- Changes in animal migration and life cycles
- Changes in plant life cycles
- Increased summer drying, wildfires and droughts
- Higher surface temperatures of up to 6.1 degrees Celsius
- Increased heat waves
- Warmer oceans
- Rising sea level
- Decreased water availability in arid and semi-arid regions
- Damaged corals
- Decrease in crops
- Decrease in plant productivity
- Areas affected by disease could expand

