The surface of the earth is constantly warmed by the sun through short wave radiation. The earth loses heat due to outgoing long wave radiation. Over a long period of time, because of the balance between ingoing and outgoing radiation the earth’s temperature remains constant, as the greenhouse gases absorb heat from the atmosphere and retain it. When it is cloudy during the night the temperatures do not drop as low as clear nights, because the clouds trap the heat from the day. The greenhouse gases in the atmosphere also act as a blanket as they prevent infrared radiation escaping. Without greenhouse gases, the earth’s average temperature would be 33 degrees C lower than today.
There are lots of different greenhouse gases that contribute towards the greenhouse effect. Water vapour has the largest contribution to the greenhouse effect, contributing between 36-72% of heat retention. Of the more dangerous greenhouse Gases, which we produce artificially, carbon dioxide is the most prominent, contributing to about 9-26% of the greenhouse effect. Other gases include methane, halocarbons, ozone, nitrous oxide, and CFCs (chlorohydrocarbons).
As we can see from this graph, the amount of carbon dioxide in the atmosphere and the global temperature have a strong correlation. This shows that the more carbon dioxide we produce, the higher our global temperature will be. The pie chart is showing what areas we have the highest carbon dioxide emissions in. Most of the carbon dioxide that we produce comes from energy supply, 26%. 19% of the carbon dioxide we produce comes from industry, however only 8% comes from residential and commercial buildings.
From this graph, we can see that sea levels have been rising since 1870. By 1930, they had risen by 2 inches, which was over a 60 year period. After 1930, they started to rise a lot faster, and by 1955, they had risen nearly another 4 inches on top of the 2 inches risen already. By 2010, since 1870, the sea levels have risen about 9 inches.
There are multiple reasons for the rise of sea levels, but they are all caused by the fact that we are producing to many greenhouse gases. As our carbon dioxide emissions are going up, so are the sea levels. Because there are more greenhouse gases, this causes the temperature of the atmosphere to go up. This has major effects on the sea level; it melts glaciers, it causes the sea to expand in volume as the molecules gain energy, and melts ice in Antarctica and Greenland, causing the volume of the sea to increase.
This image shows regions which are vulnerable to sea level rise. There are regions vulnerable to sea level rise all over the world, in many different continents and countries. There are particularly large areas in north Russia and the amazon region of Brazil. Other vulnerable areas include southeast Asia, eastern china, Indonesia, and the low countries (Belgium and the Netherlands). Most of the vulnerable regions are on the coast, but in Australia there is an entirely landlocked area vulnerable to sea level rise.
As well as sea level rise there are many other impacts global warming will have on the planet, benefits and problems. Warmer winters would mean fewer deaths, particularly among vulnerable groups like the aged in cold areas. However, the same groups are also vulnerable to additional heat, and deaths attributable to heat waves are expected to be approximately five times as great as winter deaths prevented.
There are some benefits that would occur if with global warming. People will need less heating in their houses, meaning there will be less energy used in this area. If the America’s climate warms by 1.8°F, the demand for energy used for heating would decrease by about 3-15%. Canada’s North-West Passage may become ice-free and can be used by shipping. This will increase trade in that area and could improve the economy of countries in that area surrounded by ice.
Although there are limited benefits of global warming, the problems heavily outweigh them. 220-240 extra million people will be at risk from malaria. China and central Asia will be particularly at risk. Scientists found that when temperatures increased, malaria affected people at higher altitudes than when temperatures were cooler. It is the first study on the ground to show how temperature changes can affect the risk of malaria in populations living 1,200 metres above sea level. Also as species’ habitats change more species may become extinct. The polar bear could disappear in the wild unless the pace of global warming slows. Dependent on sea ice, the animal uses it as a floating platform to catch prey. Experts believe that the Arctic sea ice is melting at a rate of 9% per decade, endangering the polar bear’s habitat and existence.
