Global Climate Model

The fundamental physical laws and observations are basis of Climatic models. A consensus on the existence of climatic change cannot be reached due to the non-existence of long term historical climate data. Climate change was considered to be a myth till the twentieth century but the current studies and evidence reflects that natural systems are already being affected by regional climatic change. Availability of food and water is affected by the risings temperature, changes in precipitation patterns and natural disasters leading to rise in poverty, increased volatility in food prices, and heightened regional tensions, affecting international stability and security. All of the changes in physical parameters stand as the global dimensions of

Scientists calculated the sea level has been continuously rising since 1990 at a rate of at least 0.04 to 0.1 inches (3.4mm) per year, increasing 65 - 90 percent above the twentieth century average. When the oceans warm due to an increasing global temperature and seawater expands occupying more space along with water from the melting ice sheets. The U.S. East Coast and Gulf of Mexico experienced the world's fastest rates of sea level rise in the twentieth century due to local and regional factors. After the era of industrialization, the thermal expansion was the main driver of global sea level rise for 75 - 100 years but over the time the accelerated shrinking of ice sheets has taken over as a major contributor. Winter temperature has increased more than summer temperature in Arctic leading to loss of ice sheets. Greenland and West Antarctica ice sheets will have the greatest effect on long-term sea level rise. Forty percent of the world’s population lives within 62 miles (100 kilometers) of the ocean. sea-level rise increases erosion of stranded beaches, wetlands, and coastal infrastructure due to the penetration of waves further inland. People living near the cost are subjected to dangerous high ties and storm surges. These occurring on top of the elevated water level can cause potentially catastrophic damage to homes and infrastructure while the strong tides on the other hand Strong winds, rainfall, and storms that coincide with high tides can result in even more extensive and damaging floods. The low-lying coastal areas tend to gradually submerge in the sea, eating up land and leaving more problems due to salt water intrusion. In the case of Pakistan loss of mountain glacier and snow pack is more to threaten the civilization then the rising sea levels. During each summer the accelerated rate of glaciers meltdown