Climate change- background info What is climate change? Climate is the average weather of a place varying from season to season.
Like, for an example a place might be very hot and in summer but this same place could be very cold in the winter. Climate change is the change in these weather averages regionally and globally.(3)What causes climate change? Natural factors: There are many natural factors which can influence earth’s climate (All the world’s climates combined),which causes climate change. There are 3 primary natural factors that cause climate change: Earth’s orbital change and change in earth’s axis of rotation – We all know that the earth orbits around the sun , and change in this oribat can cause climate change. As sometimes this orbit becomes more of an egg shape which makes it so that at times during its orbit the earth is closer and other times further from the sun. These orbital changes, change earth’s climate (colder or hotter).
Next, change in earth’s axis of rotation can also cause climate change as over about 41 000 years earth’s angle of rotation 21.3 degrees to 24.5 degrees and then back again. As the angle increases summers get hotter and winters get colder. (1)Solar irradiance- or in other words the sun’s energy output. Meaning if solar activity (sun’s energy out) is increased its gets hotter and when decreased it gets colder.
But satellite information show that solar irradiance is not the reason why we are facing current global warming trends as there has only been a slight drop in solar irradiance meaning this is not the reason for recent warming trends. (1)Volcanic Eruptions – are another natural factor which causes climate change as major volcanic eruptions release gases such sulphur dioxide and carbon dioxide. When sulphur dioxide is in the stratosphere it converts to sulfuric acid which then condenses into sulfate aerosols. Sulfate aerosol increases the reflection of radiation (sunlight) back in to space, thus cooling earth’s lower atmosphere (troposphere).
Next, carbon dioxide is a greenhouse gas which can increase global warming but these co2 emissions are no where no the amount humans put into the earth.(4)Other natural factors that cause climate change are ocean current, as ocean currents carry heat around the earth and when the direction of these current is changed, different areas can become cooler or warmer. Little change in the earth’s ocean current can cause a big effect on the earth and coastal climates.
This happens because oceans can store a lot of heat.(1) Human factors The greenhouse effect is a natural process and life on earth depends on it. The greenhouse effect involves , sunlight a form of radiation passes through the earth’s atmosphere (only about half passes through atmosphere), and hits the ground where most of it is absorbed and the rest is reflected back into the atmosphere where the greenhouse gases absorb about 90% of the reflected energy and radiate it back to earth which is warmed to 15 degrees celsius which is idle for life. But us humans ever since the industrial revolution have injected more greenhouse gases in the atmosphere thus increasing the greenhouse effect and casing climat (5). Some example of these greenhouse gases are: Nitrous oxide- the source for this greenhouse gas is burning of fossils fuels (coal,oil,natural gas) and nitrogen based fertilizers. The contribution of this greenhouse gas is 4%. (3)Chlorofluorocarbons(CFCs)- These greenhouse gas are chemicals used in refrigerators,air conditioning, cleaning solvents ,insulation and making of plastic foam.
These chemicals contribute 11% to the overall total of greenhouse gases.(3)Carbon dioxide (CO2)- This greenhouse gas is produced when fossil fuels are being burned such as coal , oil, and natural gas. The contribution of this greenhouse gas is 60% which makes it the main greenhouse has, one of the reason for this is that we used fossil fuels on a daily basis, about 85% of the things we do require burning of fossil fuels.
(3)Methane (CH4)- is the result of decomposition of organic matter .eg. raising of livestock, dump sites.
Methane contributes 14% to the total greenhouse gases. (3) You can see by the trends of this graph that as CO2 emissions increase. Earth’s climate increases along side with it.