Examine the Evidence Used to Investigate Long, Medium and Short-Term Climate Change. (15)

Examine the evidence used to investigate long, medium and short-term climate change. (15)

From various pieces of scientific evidence we can see the Earth's climate is changing. An example of a long term change would be pollen analysis. This study preserves pollen in peat bogs and the type of vegetation can give a clue to the current climate. However the wind can blow pollen a long distance and its reliability therefore depends on the preservation of the pollen. Another example would be carbon dioxide levels; they are sampled by using trapped bubbles over the last 800,000 years however this is only reliable if there is a direct correlation between a number of the CO2 sequences.

Some evidence for medium-term climate change would be historical records; they can help to identify differences between previous and modern-day climates. They include artistic and photographic sources, written descriptions such as diaries and records etc. However it can be argued that the purpose of the sources was not set to record climate change therefore making them potentially unrelated to the subject matter. In addition to that tree rings can also be used. A new tree ring is formed each year as a tree grows, as they’re very sensitive to changes in temperature, rainfall and sunlight. The weather conditions determine the physical state of the tree, which can be analysed to check for distress/extra growth etc.They are very accurate however the tree ring records are very limited.


Lastly evidence of short term climate change can be collected in the form of weather data, as details of weather conditions have been constantly recorded since 1861.These can be used to show detailed changes in the climate over this short amount of time. These records have proven to be very important as they can prove that the global sea level has increased. For example between 1961 and 2003 it rose by 1.8mm per year. To conclude another method would be ice response, as ice is found in glaciers, ice caps...