Changes

Assessments by the [[United Nations]] promote the view that most of the warming since around 1850 is likely human-caused. In February, 2007, the [[IPCC|Intergovernmental Panel on Climate Change]], a body of scientists<ref>http://www.chicagotribune.com/news/nationworld/chi-0704280477apr29,1,4275902.story?coll=chi-newsnationworld-hed</ref> established by the [[United Nations]], released their fourth assessment report on climate change. That report concluded that most of recent global warming was "very likely" caused by human activity<ref>http://news.bbc.co.uk/2/hi/science/nature/6321351.stm</ref>. It says that increases in atmospheric concentrations of [[greenhouse gas]]es cause warming.

Assessments by the [[United Nations]] promote the view that most of the warming since around 1850 is likely human-caused. In February, 2007, the [[IPCC|Intergovernmental Panel on Climate Change]], a body of scientists<ref>http://www.chicagotribune.com/news/nationworld/chi-0704280477apr29,1,4275902.story?coll=chi-newsnationworld-hed</ref> established by the [[United Nations]], released their fourth assessment report on climate change. That report concluded that most of recent global warming was "very likely" caused by human activity<ref>http://news.bbc.co.uk/2/hi/science/nature/6321351.stm</ref>. It says that increases in atmospheric concentrations of [[greenhouse gas]]es cause warming.

According to temperature reconstruction made within an evolutionary paradigm, there have been many cycles of naturally-caused global warming and cooling over many millions of years (see [[climate cycles]]). Some scientists, including [[Richard Lindzen]] of [[MIT]], [[Sallie Baliunas]] of [[Harvard]] and [[Fred Singer]] (independent), say that the recent warming could be part of another natural cycle or random fluctuations in the atmosphere.

According to temperature reconstruction made within an evolutionary paradigm, there have been many cycles of naturally-caused global warming and cooling over many millions of years (see [[climate cycles]]). Some scientists, including [[Richard Lindzen]] of [[MIT]], [[Sallie Baliunas]] of [[Harvard]] and [[Fred Singer]] (independent), say that the recent warming could be part of another natural cycle or random fluctuations in the atmosphere. However, most scientists agree that human activities are causing the plant to warm.  

==The Hockey Stick Temperature Reconstruction==

==The Hockey Stick Temperature Reconstruction==