The Science of Climate Change

 

 

“… there have been natural and cyclical variations in the Earth’s climate in the past, [but] the current rate of change is faster than anything the planet has experienced before.”
 
Number of reef provinces bleaching since 1978.  Arrow indicate strong El Nino years.  While some of the trend can be explain the increasing rend with time.
Source: Hoegh-Guldberg 1999
The scientific evidence is indisputable. The world’s climate changed during the 20th century. Global average surface temperature increased by about 0.6°C; snow cover and ice extent decreased; the temperature and acidity of oceans changed; and sea levels around the world increased between 10 cm and 20 cm. Seasonal patterns, including rainfall, have also changed the world over. The 1990s were the hottest decade and 1998 the warmest year on record, since temperature recording began some 150 years ago.  And, while it is true that there have been natural and cyclical variations in the Earth’s climate in the past, it is also true that the current rate of change is faster than anything the planet has experienced before.
 
What’s more, there is evidence that the pace of change has been accelerated by human activities, or anthropogenic causes, such as the burning of fossil fuels for energy and the cutting down of forests for agriculture. Such activities have helped increase the concentration, and alter the balance, of the greenhouse gases  that are responsible for keeping the Earth warm. The net effect has been an enhanced greenhouse effect  and warmer surface and sea temperatures. These have in turn affected nature and society in a number of different ways.

 

For the latest science, see  IPCC website; Hadley Centre

 

To understand the “jargon of climate change” see our glossary.

 

 

 


 

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