In the context of global warming, discuss the extent to which you agree with this statement.
Global warming has been happening for millions of years through periods of glacial’s and interglacial’s. The last glacial period occurred during the last years of the Pleistocene, approximately 110,000 to 12,000 years ago and ever since then the earth has been warming up. However the change between the heating and cooling used to be for natural reasons but now scientist are beginning 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 analysed as every year a new layer of ice will form and so the trapped gases from each year can be analysed. Sediments on the sea floor can similarly be analysed for the amount of O-16 or O-18 gas is present, as a colder climates would have more O-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 can 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