Without these gases the Earth would be around negative 15 Degrees Celsius, too cold to sustain life. However, past and current human activity is increasing the concentration of greenhouse gases in our atmosphere, which is contributing to changes in our climate.
Climate change refers to climatic changes resulting from the combined effect of natural drivers and human activity. Natural drivers of our climate include variations in energy output from the sun, changes in our orbit around the sun, volcanic activity, wild fires, clouds and water vapour. Human activity, chiefly the burning of fossil fuel, deforestation, waste, agricultural and industrial processes that release greenhouse gases, combine with these natural drivers to change our climate.
In the past this process has been called the 'greenhouse effect' because of similarities between the way a glasshouse works and the way greenhouse gases in the atmosphere trap heat that would have escaped into space. It has also been called 'global warming' because of the general warming trend observed for the globe. However, both of these terms have been replaced with the term 'climate change' to better reflect the anticipated climate variability, extremes in weather and other physical changes such as sea-level rise, ocean acidification and changes in wind patterns.
For more information visit:
http://www.mfe.govt.nz/issues/climate/index.html
Local impacts of climate change
Local councils around New Zealand have been advised about the anticipated impacts of climate change by the New Zealand Government. Following this advice Christchurch can expect a range of social, economic and environmental changes. Our first priory must be to reduce greenhouse gas emissions now, to help global efforts in managing future changes to our climate. However, we must also take steps to ensure our community is resilient to the unavoidable impacts of climate change.
Within the next 100 years Christchurch must prepare for:
- 50 – 80 centimetre rise in sea-level;
- a temperature increase of 2 degrees; and
- changes in rainfall and extreme weather events.
For more information visit:
Climate change resources
