CO2 is warming the planet.

Judge as of 2010. True: the scientific assessments of the time (for example IPCC AR4 in 2007, and statements by national academies) concluded that rising CO2 concentrations are warming the planet. Mostly true: the assessments attributed warming to greenhouse gases generally, with CO2 as the main one. Mixed: the scientific evidence was substantially divided. Mostly false: CO2 was found to have only a minor role. False: the scientific evidence showed that CO2 does not cause warming.

Set before the research began.

1. E1 Climate Change 2007: The Physical Science Basis (Summary for Policymakers) Intergovernmental Panel on Climate Change (IPCC) · 2007

   “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”

2. E2 The Science of Climate Change: Questions and Answers Australian Academy of Science · August 2010

   “It is known that increasing the atmospheric concentration of the principal anthropogenic greenhouse gas, CO2, leads to higher mean global surface temperatures.”

3. E3 The Science of Climate Change: Questions and Answers Australian Academy of Science · August 2010

   “Human activities are increasing greenhouse gas levels in the atmosphere. It is very likely that most of the recent observed global warming is caused by this increase in greenhouse gases.”

4. E4 IPCC adopts major assessment of climate change science DieselNet · 6 February 2007

   “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations”

The IPCC AR4 Summary for Policymakers (E1, also reported in E4) concluded that most of the warming observed since the mid-20th century was very likely due to increased anthropogenic greenhouse gas concentrations. The Australian Academy of Science's 2010 report states that higher atmospheric concentrations of CO2, the principal anthropogenic greenhouse gas, lead to higher mean global surface temperatures (E2). The same report says it is very likely that most of the recent warming is caused by rising greenhouse gases (E3). Under the criteria, these assessments from the time support the claim that CO2 is warming the planet.