Talk:Global warming

AGU is considering updating its position on climate change

The American Geophysical Union (AGU) is considering updating its 2003 position on the Human Impacts on Climate.[1] Some wish to see the AGU make a stronger statement. Others want the AGU to consider its position based on new skeptical science. Below is my comment to the AGU. Editors can use these links as a resource in improving the article. Specifically, the section on climate sensitivity needs work. While I respect Lord Monckton, he is a journalist. When possible, I believe it is preferable for an encyclopedia to cite peer-reviewed science over the work of a journalist. Two important peer-reviewed papers were published in 2007 which call into question the climate sensitivity estimates used by IPCC. Other issues are also important, such as the conflict of interest and the Hockey Stick Controversy. Here is my comment to AGU with a few added references:

I agree with Fred Singer that the AGU has two choices - to follow the IPCC or to examine the scientific evidence independently. There are good reasons to examine the evidence independently.

1. A flurry of papers published in 2007 and 2008 have changed the scientific climate change landscape. These papers were published after the cutoff date for the IPCC's Fourth Assessment Report. I will mention just a few important papers, including two on climate sensitivity: One by Stephen Schwartz of Brookhaven National Lab and one by Petr Chylek of Los Alamos National Lab. Chylek and Schwartz approached the question differently. Chylek had new data on aerosols and arrived at an estimate at the low end of the IPCC range.[2] Schwartz took a new and compelling approach and arrived at an estimate even lower.[3] Another key paper, by Roy Spencer and co-authors, examined a newly discovered negative feedback over the tropics.[4] They identified this negative feedback as possibly being the "Infrared Iris" effect hypothesized by Richard Lindzen. If confirmed, this discovery may explain why the Earth has not warmed as much as AGW theory projected over the last 30 years.

2. An independent review is also warranted because the IPCC put key authors in charge of reviewing their own papers. The authors are in a position to keep alternative viewpoints from being presented. This is not an independent review. Roger Pielke of CIRES has pointed out the problems with this approach and detailed the neglect of key research findings when they were contrary to the conclusions of the IPCC authors/reviewers.

• http://climatesci.org/2007/09/01/the-2007-ipcc-assessment-process-its-obvious-conflict-of-interest/
• http://climatesci.org/2007/11/30/climate-metric-reality-check-1-the-sum-of-climate-forcings-and-feedbacks-is-less-than-the-2007-ipcc-best-estimate-of-human-climate-forcings/
• http://climatesci.org/2007/06/20/documentation-of-ipcc-wg1-bias-by-roger-a-pielke-sr-and-dallas-staley-part-i/
• http://climatesci.org/2007/07/20/documentation-of-ipcc-wg1-bias-by-roger-a-pielke-sr-and-dallas-staley-part-ii/

3. The IPCC has not spent any time or effort in validating the General Circulation Models used to project future climate. The IPCC has discussed ocean heat content but has not used this important metric in model validation. Nor has the IPCC spent any time or effort in researching or using the principles of scientific forecasting. At least three peer-reviewed journals are dedicated to scientific forecasting, but the IPCC seem to be completely unaware of this literature. We now have enough data to conduct computer model validity tests. Some of these should be done using ocean heat content. Any resulting projections should meet the principles involved in scientific forecasting. Here are links to initial work in these areas.

• http://sciencepolicy.colorado.edu/prometheus/archives/prediction_and_forecasting/001376letter_to_nature_geo.html
• http://climatesci.org/2008/05/21/can-the-ipcc-model-projections-of-global-warming-be-evaluated-from-just-several-years-of-data/
• http://forecastingprinciples.com/Public_Policy/WarmAudit31.pdf

4. The IPCC continues to promote "hockey stick" graphs of paleoclimate reconstructions. The IPCC claims these reconstructions are independent confirmations of the original MBH reconstructions debunked by Steve McIntyre and Ross McKitrick. However, the National Academy of Sciences investigated and agreed with McIntyre and McKitrick that strip bark trees such as bristlecone pines are not temperature proxies and should not be used in reconstructions. The new, supposedly "independent," reconstructions promoted by the IPCC all use strip bark trees or other non-temperature proxies. It is time for an independent review of this controversy as well. Ron Cram 16:03, 25 December 2008 (UTC)

Undone Joel M. Kaufmann's edit

I have undone Joel M. Kaufmann's recent edit (see diff) because it is far different from expected Citizendium style. If you wish to make comments on an article on the Citizendium, you can do so on the talk page. Posting these first-person critical comments in bold, inline in the article is not appropriate, especially as some of the comments suggest that other authors of this article have been engaged in "confusing the unwary" and acting "fraudulently". The edit was also marked as 'minor' but quite clearly was not. --Tom Morris 23:01, 6 January 2009 (UTC)

What caused it

I skimmed the article without finding anything which explains how "greenhouse gases" have contributed to the modern period of global warming. Do I need to look harder, or is this a chance for us to improve the writing?

Also, I'm very curious about what has caused other periods of global warming, particularly the warm periods between the ice ages. And what caused the ice ages to stop (or start), if human industry did not contribute substantially to "greenhouse warming"?

I'd like to see a little more about the sun's output. I don't have any degrees in science, but I've read some non-technical articles about solar variation affecting the absorption of cosmic rays in the earth's atmosphere. Cosmic rays are apparently related to cloud formation, which in turn influences terrestrial warming.

• Am I describing this theory correctly?
• Does the theory have enough credibility to be mentioned in the article?

I'm also concerned about the politicization of the science here. I see a polarization into two camps:

1. Supporters of the Kyoto Protocol and proponents of the Greenhouse Theory of human-caused global warming
2. Opponents of the Greenhouse Theory and opponents of the Kyoto Protocol

Both camps say they are motivated by the science to support (or oppose) the treaty. Could one side be "lying"? If it's possible for a side to be less than candid about its motivation, how should the encyclopedia describe this situation? --Ed Poor 17:54, 24 January 2009 (UTC)

Small changes

I again stuck my neck out and added a few things to this hotly-debated article. I added a reference to a recent book written by skeptics, not because I like the book or agree with it (I didn't read it), but because I feel that CZ should not ignore the view of the skeptics. To counterbalance somewhat I also linked to the official APS statement that supports the IPCC. (If somebody wants to know, I'm not a skeptic or believer. One thing I'm sure of: the world will run out of fossil fuels and then the CO₂ emission will stop).--Paul Wormer 15:36, 21 November 2009 (UTC)

Period in question

Temperature is up since 1850, or since 1906, or since the mid-twentieth century.

From 1850 to 2010, the increase could be due to a "recovery" from the Little Ice Age, or AGW, or both. But are we talking about the last 160 years, the last 104 years, or the last 60 years?

This is not a quibble. There is a healthy controversy -- among climate scientists -- as to what portion of the warming in the various periods is natural or man-made.

And I'm going to segue from this lack of clarity about the time period being discussed, to the utter lack of objectivity about the causes of global warming. Advocates of the Kyoto Protocol (global warming treaty) all support the AGW theory. On the other hand, AGW skeptics generally oppose the Kyoto Protocol. (Each side says it's simply following the science and that the other side is politically motivated.)

I hope we can explain clearly the physical forces involved in:

• the AGW: ups and downs in "greenhouse gases" like CO2 correlate with subsequent ups and downs in worldwide near-surface air temperature, and therefore must be the cause
• other theories: e.g., that variations in the sunspot cycle correlate closely with 20th century variations in near-surface air temperature, and therefore must be the cause

I also hope that we won't try to do "science by ballot box" but will explain the actual theories. For example, CO2 is analogous to the glass in a greenhouse, keeping "in" heat in the form of infrared rays by bouncing them back from the middle atmosphere to the ground again. Another example, variations in sunspots affect the solar wind which determines the extent to which cosmic rays penetrate the earth's atmosphere, which in turn affects cloud formation, and the height and extent of cloud cover determines how much infrared radiation reaches the earth's surface to heat it up.

I'd like our articles about climate to focus more on the science itself, rather than on the number (or prominence) of people and organizations who endorse or reject any particular theory. --Ed Poor 02:39, 15 April 2010 (UTC)