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
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
that are responsible for keeping the Earth warm.
The net effect has been an enhanced
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.