Global warming due to the presence of radiatively active greenhouse gases in the Earth’s troposphere is the phenomenon responsible for earth having a near-surface atmospheric temperature 33 degree Celsius higher than what would have, had there been no greenhouse jacket (288K vs 255K). It also provides protection against extreme variations in day and night time temperatures on this planet. This excellent thermo-jacket thus helps life forms sustain on earth which would otherwise have been impossible. So, contrary to the popular belief, global warming actually helps life on earth.
Anthropogenic sources of a number of gases are enhancing the greenhouse effect, leading us towards enhanced global warming and a future of uncertain global climate. Several current trends clearly demonstrate that global warming is directly impacting on rising sea levels and consequent inundation of human habitats, the melting of ice caps, depleting sweet water resources and significant worldwide extreme changes in climatic conditions that cause frequent episodes of flood, cyclones, landslides, tsunami, drought etc. In short, global warming represents a fundamental threat to all living things on earth.