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However the change between the heating and cooling used to be for natural reasons but now scientist are egging to think that humans may be effecting this change meaning that the earth is warming. Climate change (a long term change in weather) can be seen from many sources. Historical evidence, such as agriculture reports, as it indirectly show different conditions as different crops grow better in different conditions and weather records can be used to show the weather in the past and the present (only since records began in 1861 ) which show a detailed change in the climate in only a short period of time.
Physical evidence can also show climate change. Ice cores, sea sediment, a change in sea level and retreating glaciers all can show heating and cooling. Ice cores can be analyses as every year a new layer of ice will form and so the trapped gases from each year can be analyses. Sediments on the sea floor can similarly be analyses for the amount of 0-16 or 0-18 gas is present, as a colder climates would have more 0-18 present. Sea level change is affected by changes such as ice melting, so if glaciers are retreating further there will be more water in the sea therefore it will rise.
Finally biological evidence can be used as a source. Pollen analysis an date pollen to see when it was deposited, and then they can work out what the climate was like by seeing the conditions plants live in now. Tree rings can also be used, this is a similar method to ice cores, since a new ring grows every year so you can date the tree and then look at the thickness of each ring to tell what the climate was like. All this can show evidence that the temperature of the climate is rising and global warming is happening.
The rate at which the global temperature is rising in unheard of in historical terms and scientists believe that is mainly down to humans. Increasing amounts of CO and methane gas are major contributors to global warming as they trap much of the long wave radiation trying to escape. Humans add to the volume of CO in the atmosphere by burning fossil fuels, such as coal and Oil. Since the mid 19th century CO has increased form pumps to pumps.
Deforestation removes plant that absorb CO so not as much goes into the atmosphere so when they are cut down they stop taking in CO meaning that there is more in the atmosphere rather than organic matter. CO is also released when trees as burnt. One other human activity that releases ethane and nitrous oxides is farming. Nitrous oxides are released into the atmosphere when farmers use fertilizers. Livestock produce a lot of methane which all goes into the atmosphere. And also rice payday fields emit methane. The causes of global warming are major to do with human activities, and we must change what we do.
The impact of what we do on the earth has huge global impacts. Precipitation patterns will change and mid to high latitudes will receive a lot more precipitation and drier areas are likely to get drier for example Africa and Central America. This is due to changes in ocean circulation and wind patterns. These changes will also cause more major weather evens such as floods, droughts and storms. The spread of heat related illness could rise in countries that are more likely to get droughts now and food-borne illnesses may increase too as temperatures rise.
Also disease vectors will be able to move to more countries that are currently too cold so malaria could become more of a problem. In some areas higher temperatures and less rain fall will reduce river flow and ground water flow so reservoirs may dry up, this could cause conflict between countries as in some areas water supply is likely to decrease by 10% by 2020. Food productivity may become a problem as well for a similar reason, however the type of crops grown may change in areas to crops that prefer that areas weather condition.
The melting of glaciers and ice caps cause a rise in sea level which means habitats are lost and it will cause flooding in coastal areas and low lying areas this could mean that areas of SE Asia will be lost as well as islands in the Pacific and Indian ocean. These impacts reflect the problems of the earths ‘fever’ and we need to respond to hem to put it right again. The response at a global level, to global warming, have been to put a protocol together, called the Kyoto Protocol, aimed at reducing emissions. This agreement was formed in 1997 in order to monitor and reduce greenhouse gases.
Developing countries and developed countries are both included in the scheme, developed countries had to cut emissions by 5% of their 1990 level between 2008 and 2012 and developing countries just need to monitor their levels so that they don’t rise. In order to persuade countries to keep to this incentives are given in the form of carbon credits, which countries can then sell to other countries if they are struggling. However the four countries with the highest CO emissions did not sign up originally in fear of it effecting their growth and economy. Responses at a national level are also helpful .
Changing the energy mix Of the country to use more renewable energy sources will reduce green house emissions from power stations, for example in the I-J a 40% reduction of emissions by 2020 will be achieved by changing the energy mix. Also carbon capture will cut the amount of CO as it rainspouts the excess CO to places where it can be stored safely. This has the potential to reduce emissions by 90%. Encouraging home owners to reduce fuel consumption in there homes would also help and giving financial incentives to people who create there own energy from renewable resources will hopefully help cut emissions.
Furthermore if people were to use their cars less and chose to use public transport, walk or cycle emissions will be cut further. Many cities have now set up park and ride schemes, for example Oxford, so that you don t have to take you car as far. Finally local responses to limited change include recycling more so there is less waste going to land fill, which produces methane gas and choosing energy efficient appliances as many old appliances produce 50% more emissions then new technologies.
These are some things that we have to do to lower the temperature of the earth. In conclusion, AY Gores statement, feel, is correct as we are contributing to the effects of global warming by emitting more CO and methane gas into the atmosphere so much of the long wave radiation cannot escape. I think that all international, national and local are all-important, as they will all bring costive consequences to responding to global warming even if some have better affects than others.