Global Warming: Fact or Fiction?

[Aractus]

Then let me clarify. The vast majority of climate scientists agree that CO2 and the other anthropocentric gasses do contribute to climate change.

The Fourth IPCC report (2007) however made statements in the Summary for Policymakers that not every climate scientist agrees with, and did not go through the proper peer-review process that the rest of the paper did. This meant that only a handful of those high up like Mann got to decide ultimately what it said. The statements made within the summary were presented (politically) as scientific consensus when they were not. On the whole however the report is good, and contains information across a wide range of issues within the science.

The Summary should have had equal contribution from scientists representing all sections of the IPCC report, it did not. It only represents "Working Group I" and from the reports I read I the past, only some of those involved in WGI got to participate in the section. Group II and Group III had no involvement whatsoever in it.

Excerpts from Summary for Policymakers.

• Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea level rise for more than a millennium, due to the timescales required for removal of this gas from the atmosphere." [link]
  
• It is very likely that hot extremes, heat waves and heavy precipitation events will continue to become more frequent.
  
• It is likely that increases in greenhouse gas concentrations alone would have caused more warming than observed because volcanic and anthropogenic aerosols have offset some warming that would otherwise have taken place. [link]
  
• It is very unlikely that climate changes of at least the seven centuries prior to 1950 were due to variability generated within the climate system alone. A significant fraction of the reconstructed Northern Hemisphere inter-decadal temperature variability over those centuries is very likely attributable to volcanic eruptions and changes in solar irradiance, and it is likely that anthropogenic forcing contributed to the early 20th-century warming evident in these records.

Many of the statements made were based off the assumption that the planet would warm by 4-8 degrees Celsius or more over the next 100 years, something that is not consensus and has since been revised down.