Just because Britannica labels natural cycles as climate change doesn’t make it any more correct than labeling cycling from winter to spring weather change.
But you may believe anything you like.
A long-term change in the earth’s climate, especially a change due to an increase in the average atmospheric temperature:
Melting glaciers imply that life in the Arctic is affected by climate change.
http://dictionary.reference.com/browse/climate+change
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Climate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as “global warming”.
http://en.wikipedia.org/wiki/Climate_change
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Climate change is a large-scale, long-term shift in the planet’s weather patterns or average temperatures. Earth has had tropical climates and ice ages many times in its 4.5 billion years.
http://www.metoffice.gov.uk/climate-guide/climate-change