Assignment, Pages 2 (335 words)
Global warming what is it? Global warming refers to an average increase in theEarth’s temperature, which in turn causes changes in climate. So what’s the big deal you ask? Well the big deal is, if temperatures rise above normal levels for a few days, it’s no big deal, the Earth will stay more or less the same, but if temperatures continue to rise over a longer period of time, then the Earth may experience some serious problems!
What causes global warming? The Earth’s atmosphere contains gases that naturally help to hold in heat, these natural Greenhouse gases keep our atmosphere warm long after the sun has set and absorb the Sun’s heat during the day, keeping thetemperature from getting to high.
Over the past 100 years, humans have altered the chemical composition of the earth’s atmosphere through the buildup of greenhouse gases,therefore resulting in Global Warming. Why are greenhouse gas concentrations increasing? Some greenhouse gases occur naturally in the atmosphere, while others result from human activities.
Naturally occurring greenhouse gases include carbon dioxide,methane, and nitrous oxide.
Certain human activities, add to the levels of most of these naturally occurring gases. Carbon dioxide is released when solid waste, fossil fuels (oil,natural gas, and coal), and wood are burned. Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from the decomposition of organic wastes in landfills and the raising of livestock. Finally Nitrous oxide is emitted during agricultural and industrial activities.
What are some of the effects, due to global warming? Surface temperatures have increased 1.0°C-3°C since the late 19th century. The 20th century’s 10 warmest years have all occurred in the last 15 years of the century. Worldwide precipitation over land has increased by about one percent and globally, sea level has risen 4-8 inches over the past century. Global warming has also decreased snow cover in the northern hemisphere,and melted glaciers. Changing regional climate could alter crops yields, water supplies,and forests. It could also affect the health of ecosystems, animals and even humans.