Human activities are rapidly changing the chemical composition of the atmosphere (Karling). The high release of greenhouse gases mostly from burning of fossil fuels has caused the global temperatures to rise resulting in what is known as global warming. Global surface temperatures have increased 0.5-1.0F since the late 19th century. Early on this was mostly attributed to the industrial revolution and thereafter due to population growth, fossil fuel burning, and deforestation. With the rising global temperatures various climatic changes are expected. These include rise in sea level, change in precipitation patterns and other local climatic changes. These changes will eventually alter the ecosystem and this will in turn affect the water supply, crop yields, and forest land.
Infectious diseases is one of the major threats that global warming poses to human health (Ward). As temperatures rise, disease-carrying mosquitoes and rodents move into new areas, infecting people in their wake. The spread of diseases such as dengue, malaria and others have been linked to the rise in global temperatures. .
The United States is the largest global warming nation in the world. However, it and other well to do regions of the world will not suffer the most from global warming but rather it will be the poorest and least adaptable regions that will be affected most from the climate change that will result over the next 100 years. This is because "the less developed nations are more vulnerable due to a larger share of their economies being in climate sensitive areas such as agriculture coupled with their low capacity to adapt to change-. .
Various policies have been adopted by various governments to try and curb the problem of global warming. Most of these policies have binding targets and timetables to drastically reduce "greenhouse gas" emissions resulting from humans' activities (Nordhaus).