What is global warming?
The "
greenhouse effect" is the warming that happens when certain gases in Earth''s atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse.. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped.
Through the burning of fossil fuels and other GHG emissions, humans are enhancing the greenhouse effect and warming Earth. Now, with concentrations of greenhouse gases rising, Earth''s remaining ice sheets (such as Greenland and Antarctica) are starting to melt too. The extra water could potentially raise sea levels significantly.
As the mercury rises, the climate can change in unexpected ways. In addition to sea levels rising, weather can become more extreme. This means more intense major storms, more rain followed by longer and drier droughts (a challenge for growing crops), changes in the ranges in which plants and animals can live, and loss of water supplies that have historically come from glaciers.
Effects of global warming ? Some impacts from increasing temperatures are already happening.
Ice is melting worldwide, especially at the Earth’s poles. This includes mountain glaciers, ice sheets covering West Antarctica and Greenland, and Arctic sea ice.
Researcher Bill Fraser has tracked the decline of the penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.
Sea level rise became faster over the last century.
Precipitation (rain and snowfall) has increased across the globe, on average.
Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters) by the end of the century, and continued melting at the poles could add between 4 and 8 inches (10 to 20 centimeters).
Hurricanes and other storms are likely to become stronger.
Floods and droughts will become more common. Rainfall in Ethiopia, where droughts are already common, could decline by 10 percent over the next 50 years.
Less fresh water will be available. If the Quelccaya ice cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who rely on it for drinking water and electricity without a source of either.
Some diseases will spread, such as malaria carried by mosquitoes.
Ecosystems will change—some species will move farther north or become more successful; others won’t be able to move and could become extinct.
Wildlife research scientist Martyn Obbard has found that since the mid-1980s, with less ice on which to live and fish for food, polar bears have gotten considerably skinnier. Polar bear biologist Ian Stirling has found a similar pattern in Hudson Bay. He fears that if sea ice disappears, the polar bears will as well.
Causes of global warming?
The United Nations formed a group of scientists called the International Panel on Climate Change, or IPCC. The IPCC meets every few years to review the latest scientific findings and write a report about global warming.
The combustion of fossil fuels in cars, factories and electricity production. The gas responsible for the most warming is carbon dioxide, also called CO2. Other contributors include methane released from landfills and agriculture nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and the loss of forests that would otherwise store CO2. .
.A molecule of methane produces more than 20 times the warming of a molecule of CO2. Nitrous oxide is 300 times more powerful than CO2. Other gases, such as chlorofluorocarbons, have heat-trapping potential thousands of times greater than CO2. But because their concentrations are much lower than CO2, none of these gases adds as much warmth to the atmosphere as CO2 does .
Solutions of global warming?
According to the IPCC, we''d have to reduce GHG emissions to 80% of. There is also the potential to capture the carbon dioxide emitted from fossil fuels and store it underground—a process called "carbon sequestration." Increasing forestlands and making changes to the way we farm could increase the amount of carbon we''re storing.