Changes

<ref>Hansen's group at the Goddard Institute wrote, "Global warming is now 0.6&nbsp;°C [1.0&nbsp;°F] in the past three decades and 0.8&nbsp;°C [1.4&nbsp;°F] in the past century." http://data.giss.nasa.gov/gistemp/2005/</ref>

<ref>Hansen's group at the Goddard Institute wrote, "Global warming is now 0.6&nbsp;°C [1.0&nbsp;°F] in the past three decades and 0.8&nbsp;°C [1.4&nbsp;°F] in the past century." http://data.giss.nasa.gov/gistemp/2005/</ref>

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, a lot scientists also think that human activities were most likely the cause of the the planet's recent warming.  

According to temperature reconstruction made within an [[Old Earth]] 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, a lot scientists also think that human activities were most likely the cause of the the planet's recent 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 politicized [[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]], but whose members were appointed by their governments, 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. Several members of this panel later complained their contributions were misrepresented in the final report.

Assessments by the [[United Nations]] promote the view that most of the warming since around 1850 is likely human-caused. In February, 2007, the politicized [[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]], but whose members were appointed by their governments, 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. Several members of this panel later complained their contributions were misrepresented in the final report.