The presence of excessive greenhouse gases in the atmosphere

There is sufficient evidence that recent climate change is a result of human activities. Warming of the climate system is unequivocal; as is now evident from observations of increases in and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level (L9).

The presence of excessive greenhouse gases in the atmosphere causes global warming due to the greenhouse effect. The burning of fossil fuels releases carbon dioxide, the key driver. Industrialisation has increased demand for consumer goods. This increased demand fuels the production process which releases these gases.

Deforestation is also a contributor to climate change. Few trees mean little carbon dioxide converts to oxygen through the natural process of photosynthesis. The Greenhouse Effect is a natural and valuable phenomenon, without which, the planet would be uninhabitable (L11). It follows that an excess of these same gases would result in a rise in temperature and by extension, climate change.

The top polluters are transport fuels, coal in power generation and water and space heating. Existing records since the industrial revolution show a matching increase in the level of atmospheric greenhouse gases and global warming with the increase in human development. Carbon dioxide has increased by 40 % since the beginning of the industrial revolution (L2).

Global change affects terrestrial organisms and ecosystems (L13). It is the cause of some extreme weather patterns. The frequency with which heat waves, tropical cyclones, floods and droughts occur has been on the increase. The polar ice caps and the glaciers have been on a steady decrease occasioned by high global temperature.

The melting glaciers and a tremendous amount of hitherto locked away fresh water into the oceans. This will result in the rise of ocean level and the attendant flooding of , leading to migration. Terrestrial systems and organisms are responding to recent changes in climate (L14).

Climate change will continue to have an adverse effect on human health across the globe. A global temperature rise increases the range of disease vectors like mosquitoes, ticks and like Malaria and Dengue. Human health is also certain to be negatively affected by extreme weather like heat waves and flooding.

Fall in food supplies due to the vagaries of climate change will also cause a rise in cases of nutritional maladies. Higher temperature and are already disrupting agricultural production systems across the world and affecting food security. Climate change has also led to conflict between communities fighting over access to resources. It has also led to many instances of migration.

Any preventative or mitigating measures will have to tackle climate change by providing alternative energy sources, aimed at reducing emissions to a sustainable level. The alternatives are wind power, solar power, bio fuels and hydroelectric power. Considerable savings could be realised from effecting energy saving solutions.