On several occasions we have mentioned that climate models that do not assume AGW cannot match the observed warming. Here is an example:
Description
This graph shows two simulations of 20th century global mean temperatures compared with observed temperatures (dotted line). The red line (higher up on the right-hand side graph) shows simulated temperatures including human influences (e.g., greenhouse gases and aerosols), the blue line (lower down on the right-hand side graph) shows simulated temperatures excluding human influences. The graph is adapted from Hegerl et al. (2007) (referred to by the cited source).
From the cited Lindsey (2010) public-domain source: "Reconstructions of global temperature that include greenhouse gas increases and other human influences (red line, based on many models) closely match measured temperatures (dashed line). Those that only include natural influences (blue line, based on many models) show a slight cooling, which has not occurred. The ability of models to generate reasonable histories of global temperature is verified by their response to four 20th-century volcanic eruptions: each eruption caused brief cooling that appeared in observed as well as modeled records." For more information, see attribution of recent climate change.
References:
Hegerl, G., et al. (2007). Chapter 9: Understanding and attributing climate change. In Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (Solomon, S., et al., (eds.)), Cambridge University Press.
Date: 4 May 2010
Source: natural_anthropogenic_models_narrow.png, in: If Earth has warmed and cooled throughout history, what makes scientists think that humans are causing global warming now? part of: Climate Q&A : Blogs. Publisher: Earth Observatory, part of the EOS Project Science Office, located at NASA Goddard Space Flight Center
Author: Rebecca Lindsey
Permission:
(Reusing this file)
Image Use Policy: "Most materials published on the Earth Observatory, including images, are freely available for re-publication or re-use, including commercial purposes, with the following exceptions: *where copyright is indicated, you must obtain the copyright holder’s permission; we usually provide links to the organization that holds the copyright, *images from the SeaWiFS sensor older than five years are in the public domain and can be re-used or re-published for any purpose. Images less than five years old can be re-used only for educational or scientific purposes; any commercial use of such images must be coordinated with GeoEye. We ask that NASA’s Earth Observatory be given credit for its original materials; the only mandatory credit is NASA."
https://en.wikipedia.org/wiki/Attribution_of_recent_climate_change
Description
This graph shows two simulations of 20th century global mean temperatures compared with observed temperatures (dotted line). The red line (higher up on the right-hand side graph) shows simulated temperatures including human influences (e.g., greenhouse gases and aerosols), the blue line (lower down on the right-hand side graph) shows simulated temperatures excluding human influences. The graph is adapted from Hegerl et al. (2007) (referred to by the cited source).
From the cited Lindsey (2010) public-domain source: "Reconstructions of global temperature that include greenhouse gas increases and other human influences (red line, based on many models) closely match measured temperatures (dashed line). Those that only include natural influences (blue line, based on many models) show a slight cooling, which has not occurred. The ability of models to generate reasonable histories of global temperature is verified by their response to four 20th-century volcanic eruptions: each eruption caused brief cooling that appeared in observed as well as modeled records." For more information, see attribution of recent climate change.
References:
Hegerl, G., et al. (2007). Chapter 9: Understanding and attributing climate change. In Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (Solomon, S., et al., (eds.)), Cambridge University Press.
Date: 4 May 2010
Source: natural_anthropogenic_models_narrow.png, in: If Earth has warmed and cooled throughout history, what makes scientists think that humans are causing global warming now? part of: Climate Q&A : Blogs. Publisher: Earth Observatory, part of the EOS Project Science Office, located at NASA Goddard Space Flight Center
Author: Rebecca Lindsey
Permission:
(Reusing this file)
Image Use Policy: "Most materials published on the Earth Observatory, including images, are freely available for re-publication or re-use, including commercial purposes, with the following exceptions: *where copyright is indicated, you must obtain the copyright holder’s permission; we usually provide links to the organization that holds the copyright, *images from the SeaWiFS sensor older than five years are in the public domain and can be re-used or re-published for any purpose. Images less than five years old can be re-used only for educational or scientific purposes; any commercial use of such images must be coordinated with GeoEye. We ask that NASA’s Earth Observatory be given credit for its original materials; the only mandatory credit is NASA."
https://en.wikipedia.org/wiki/Attribution_of_recent_climate_change
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