Climate change is a long-term change in the earth's climate, especially a change due to an increase in the average atmospheric temperature. However, we could consider changes to wind, ocean currents and for many parts of the world changes to precipitation which could affect access to that vital life giving resource, water. Part of this is the current phenomenon of Global warming, which can be defined as the recent trend of an increase in global temperatures.
There are several sources of evidence for Climate change, including;
1. Instrumental readings
It has been shown that over the last 100 years, Earth's average surface temperature increased by about 0.8 °C (1.4 °F) and the rate of temperature increase sped up towards the end of that time frame. Scientists are more than 90% certain most of it is caused by human activities which have increased concentrations of greenhouse gases such as deforestation and burning fossil fuels.
2. Retreating glaciers and shrinking ice sheets
The World Glacier monitoring Service collects information every year on the sizes of glaciers around the world. Data shows that glaciers are shrinking significantly all around the world. The Arctic ice sheet has also thinned to half its thickness over the past 30 years, and we have seen the breakup of huge Ice Shelves in Antarctica.
3. Ice cores
Scientists have drilled out a huge core of ice in Antarctica. The air trapped in bubbles in the ice can be analysed and this has shown that the Earth is normally cooler than it is now and that Ice ages are common. It also shows a very strong link between CO2 concentrations and temperature.
4. Seasons shifting – such as spring arriving earlier
Spring is arriving earlier in the UK. Birds are nesting earlier and bulbs such as daffodils are flowering earlier. The Telegraph reported that spring now arrives 11 days earlier than in the 19th century.