Climate Change, A Real Problem

The overwhelming body of scientific evidence demonstrates that the earth is warming. Climate change is happening, caused in large part by human activity, its impacts are beginning to be experienced and these damaging effects will only increase in the decades ahead. Greenhouse emissions from cars and other human activities are the primary cause of the contemporary global warming. Due to the combustion of fossil fuels, atmospheric concentrations of CO2, the principal human-produced greenhouse gas, are at a level unequaled for at least 800 000 yeard. The greenhouse gases (GHGs) from human activities are trapping more of the sun's heat in the earth's atmosphere, resulting in warming. Over the last century, the global average temperatures rose by almost 1.5 degrees F, and the Arctic warmed about twice as much. The oceans have also warmed, especially within  1 000 feet of the surface.
Carbon dioxide and other GHGs always have been present in the atmosphere, keeping the earth hospitable to life by trapping heat and warming our atmosphere. Since the industrial revolution emissions of these gases from human activity have increased steadily, trapping more heat and amplifying the greenhouse effect. Since pre-industrial times, atmospheric CO2 concentrations have increased by 40% and concentrations of other GHGs have grown significantly as well. global average temperatures have risen both on land and in the oceans, with observable impacts already occuring that presage increasingly severe changes in the future. Polar ice is melting at record rates. Glaciers around the globe are in retreat. Storms, including huricanes, are increasing in intensity. Ecosystems around the world already are reacting as plant and animal species  struggle to adapt  to a shifting climate.
Scientists project that if the increase in man-made GHG emissions continues unabated, additional warming of 2 to 11.5 degrees F over the next century is likely, depending on how much more GHGs are emitted and how strongly the climate system responds to them. Although the range of uncertainty for future temperatures is large, even the lower end of the range is likely to have many undesirable effects on natural and human systems. Water supplies in some critical areas will dwindle as snow and ice disappear. Sea levels will rise, threatening coastal populations. Droughts and floods will become more common. Hurricanes and other powerful storms will cause more and more damage. Agricultural production could increase with slight warming in northen countries but is already declining in many low-latitude countries and will decrease everywhere with higher levels of warming due to changes in precipitation, weather extremes, and the spread of crop pests and diseases. Changing weather patterns will also change the distribution and incidence of insect-borne and waterborne diseases, such as malaria and cholera. Human health will be jeopardized by all of these changes. Changes in climate also pose substantial national security risks by expanding the number of weather-related humanitarian missions for military, by opening up new areas for military operations, as for example in the Arctic, and by putting at risk military facilities located in coastal areas.
A growing body of scientific research has documented that climate change is already underway and some dangerous impacts have already occurred. Avoiding more severe impacts in the future requires large reductions in human-induced GHG emissions in the coming decades. Many governments have committed to reduce their countries' emissions by between 50 and 80% below 2000 levels by 2050. If achieved, global emissions reduction on this scale will reduce the costs of damages and of adaptation and will reduce the probability of catastrophic outcomes. While committing  to and achieving such reductions must be a high priority, adapting to climate change that is now unavoidable is also important. Effective adaptation planning while simultaneously reducing emissions is a major challenge that requires unprecedented cooperation and participation throught the world.