Talk:Climate change

Section on natural systems

I'm interested in discussing improvements to the section of the article on "natural systems." In my opinion, the section presents a good summary of the subject, but I have some criticisms.

The section states that the Arctic will be largely ice-free by 2037. There are, however, other estimates. In IPCC AR4, some models using the SRES A2 emissions scenario projected ice-free summers by the end of the 21st century [1]. According the UK Met Office, recent models project an early "plausible" date of 2025-2030 [2].

I do not agree with how the section covers attribution of climate change. In my view, there is an undue focus on the study by Hansen et al. The section should provide a summary of the literature on attribution, rather than focussing on individual studies. AR4 contains a number of attributions which aren't mentioned, including the contribution of anthropogenic forcing to sea level rise and loss of Arctic sea ice [3].

Hansen et al's work on this issue does not appear to reflect a consensus view (Seneviratne et al., 2012:127). Kevin Trenberth has stated that "James Hansen and I are pushing to get scientists to think about and do statistics on this rather differently, and now we are not part of mainstream in this regard" [4].

The section's summary of extreme events is not consistent with the recent IPCC SREX report. The section states that in the future, there will be more intense droughts and floods. No caveats are given. By contrast, the SREX report is far more cautious in its projections of changes in droughts and floods (IPCC, 2012:11). A number of projected changes in extremes described in the SREX are not mentioned, e.g., increased intensity, duration and frequency of heat waves. Enescot (talk) 06:25, 11 February 2013 (UTC)

I've prepared a draft revision of the "natural systems" section that I would like to discuss. New or revised sentences are italicized:

"Global warming has been detected in a number of natural systems. Some of these changes are described in the section on observed temperature changes, e.g., sea level rise and widespread decreases in snow and ice extent. Anthropogenic forcing has likely contributed to some of the observed changes, including sea level rise, changes in climate extremes (such as the number of warm and cold days), declines in Arctic sea ice extent, and to glacier retreat (Hegerl et al 2007).

(as current revision) In the IPCC Fourth Assessment Report, across a range of future emission scenarios, (as current revision...) contribute 4–6 metres (13 to 20 ft) or more to sea level rise.[125]

Changes in regional climate are expected to include greater warming over land, with most warming at high northern latitudes, and least warming over the Southern Ocean and parts of the North Atlantic Ocean.[123] During the 21st century, glaciers and snow cover are projected to continue their retreat (Meehl et al 2007). Projections of declines in Arctic sea ice vary (Meehl et al 2007). Recent models suggest that Arctic summers could be ice-free (defined as ice extent less than 1 million square km) as early as 2025-2030 (UK Met Office 2012).

Future changes in precipitation are expected to follow existing trends, with reduced precipitation over subtropical land areas, and increased precipitation at subpolar latitudes and some equatorial regions (NOAA GFDL, 2007, p.1). Projections suggest a probable increase in the frequency and severity of some extreme weather events, such as heat waves (IPCC 2012, pp9-13).

Enescot (talk) 09:57, 20 February 2013 (UTC)

In view of the discussion below ("IPCC projection underestimations"), I was thinking of revising the "natural systems" section to include a summary of more recent global sea level rise projections. At present, the section only mentions the 2007 projections from the IPCC 4th Assessment (AR4). A recent (2012) literature assessment was conducted by the US National Research Council. The NRC study includes their own projections of sea level rise and cites projections by Vermeer and Rahmstorf (2009) [5][6]. I was thinking that these two projections could be cited in the section alongside those from AR4. It would probably only require one or two sentences. Alternatively, a graph of the projections could be added. Enescot (talk) 05:54, 6 March 2013 (UTC)

Draft image of sea level rise projections.

I've prepared a draft image of sea level rise projections, shown above. Enescot (talk) 06:49, 16 March 2013 (UTC)

The image for sea level rise mis-states the IPCC AR4 (2007) because it suggests IPCC stated an upper bound for their projection. That's false. The SPM says "Because understanding of some important effects driving sea level rise is too limited, this report does not assess the likelihood, nor provide a best estimate or an upper bound for sea level rise". Also, trying to put all the info in one table instead of breaking the tables into three with a header for the year makes it confusing. I was familiar with the numbers but took several seconds to orient myself. A newbie could easily miss the years on the right hand border. NewsAndEventsGuy (talk) 14:32, 29 March 2013 (UTC)

Thanks for the feedback. If you want to draw a new graph, then the current graph could be replaced. Alternatively, I'd be pleased to redraw the graph in view of your comments. However, I'm not entirely clear on what you have in mind. If the graph is to be broken up into three graphs, then I presume that each graph would have its own set of axes. In my view, it might be more straightforward to omit the 2030 and 2050 projections.

The image description does mention the limitations of the IPCC projections:

"The IPCC (2007) estimates do not include all of the possible contributions from ice sheets (US NRC, 2012, pp.84-85). According to US NRC (2012, p.88), "the IPCC (2007) projections are likely underestimates because they do not account fully for cryospheric processes"."

I've added the SPM text you've quoted to the image description. The comment could also be added to the graph itself. I should note that the other projections shown in the graph are much higher than the IPCC's. Therefore, I think it should be fairly obvious that the high-end IPCC projection is not an upper-bound estimate.

Another point is that graphs often do not include the full range of possible outcomes. An example is the IPCC's graph of temperature projections [7]. Enescot (talk) 09:56, 31 March 2013 (UTC)

I don't do graphics. If you've got the knowhow is that something you could do? I like the layout used in the graphic in this article, which would work well here, I think. NewsAndEventsGuy (talk) 23:32, 1 April 2013 (UTC)

I've found a sea level rise graph by NOAA which could be used to replace the existing graph [8]. The graph's on p.3 of the report. Enescot (talk) 09:26, 16 April 2013 (UTC)

Sea level rise projections for 2100.

I've prepared a new graph of projected sea level rise, shown above. It is based on several studies. Enescot (talk) 07:49, 5 May 2013 (UTC)

Reply to comments on User talk:Enescot#Nit police:

SPhilbrick - problem with citations: On the graph's description page, a few of the Harvard citations did not work. I've corrected them.

NewsAndEventsGuy - AR4 projections: I've responded to comments on the IPCC projections (see above). The image description explains that the IPCC did not project an upper-bound for sea-level rise. I've tried to make my graph similar to others produced by US NRC (figure 5.6, p.94) and NOAA (figure 9, p.11). As I've already stated, many projections do not include an upper-bound estimate. For example, refer to the studies cited in the graph. To repeat an earlier point, it's hard for me to see how AR4's projections could be misinterpreted. The graph shows several studies that project greater sea-level rise than AR4 does. Enescot (talk) 12:55, 5 June 2013 (UTC)

Where an RS gives no upper boundary, I'm opposed to a picture that looks like it does because I do not trust the reader to read the text that says the picture does not actually say what it appears to say at a simple glance. One way to solve this in pictorial form is to give each projection a solid outline, except for those RSs that do not express an upper boundary make that part of the border a dashed line, topped by an arrow and above the arrow add a question mark. That way, the reader instantly sees what the RS says even if the reader, like the preschoolers I know, "just looks at the pictures". NewsAndEventsGuy (talk) 15:23, 5 June 2013 (UTC)

I don't agree with your interpretation of the graph. I believe that my graph is consistent with graphs produced by reliable sources (see my previous post). As I've stated, all the SLR graphs I've looked at do not show the full range of uncertainty. In my experience, uncertainty is usually discussed in the accompanying text.

I agree that using dotted outlines on the graph instead of solid outlines would be an improvement. As for adding arrows, I disagree. I'm not aware of any graphs in reliable sources that are presented like this. Enescot (talk) 10:30, 12 June 2013 (UTC)

Dotted/pink/polkadotted..... the border is irrelevant unless it communicates information. In this case, any border across the top of a bar for IPCC AR4's sea level rise projections is likely to misrepresent what they said, i.e., they explicitly said the numbers they were giving were for only some factors affecting sea level, and did not include other factors, and their numbers did not express an upper limit. You can wrap the bar in roses, but it still needs something to graphically communicate that the RS explicitly says we should not read the top of the bar as an upper limit. I have suggested an arrow and a question mark to graphically depict the text in this RS. Your rebuttal that you have not seen a graph showing this textual info in this manner doesn't really address the issue we have to meet for graphics here. The top question we have to ask is whether our picture accurately explains the RS text. An up arrow and a question mark would do that, IMO. There are probably other ways but a simple bar that misleads folks into thinking IPCC AR4's numbers were intended as an upper limit will not. NewsAndEventsGuy (talk) 12:23, 12 June 2013 (UTC)

I've already said that I disagree with your interpretation of the graph. However, I have prepared a new graph and draft text for discussion:

Revised graph.

revised article text:

"Over the 21st century, the IPCC projects sea level rise of between 18-59 cm. The IPCC do not provide a best estimate of sea level rise, and their upper estimate of 59 cm is not an upper-bound, i.e., by 2100, global mean sea level could rise by more than 59 cm. The IPCC's projections are conservative, and may underestimate future sea level rise (see graph opposite) (US National Research Council, 2010, p.243)."

Enescot (talk) 09:44, 21 June 2013 (UTC)

We appear to be in an infinite loop. Our rules say pics have to show what the RS text shows; your legend has a type of marking for the upper bounds of an estimate; that marking appears in association with AR4; AR4 explicitly says its numbers do not provide an upper boundary. Er go, the pic does not show what the AR4 RS text says. Only a picture that graphically depicts the *lack* of an upper estimate from AR4 will align with that particular RS. I have already suggested various ways to do that. Your only reason for rejecting one of the ideas I proposed is that you have not seen anyone else do that. But our policies do not exclude images for that reason. Rather, our policies say pics should communicate RS text effectively. We seem to be at an impasse. We need a picture that shows no upper limit being expressed in AR4.

X=X+1

RETURN

NewsAndEventsGuy (talk) 15:11, 21 June 2013 (UTC)

As I've said, the graph that I've produced is entirely consistent with two reliable sources: US NRC (2012, figure 5.6, p.94) and NOAA (figure 9, p.11). You may not be satisfied with these graphs, but they still are reliable sources.

Earlier on, I did suggest that the existing graph could be replaced with one by NOAA (Figure ES 1, p.3). This graph does not include the IPCC projections. It is, however, representative of the literature, with projections ranging from 0.2-2.0 m by 2100, relative to 1992. NOAA state: "We have very high confidence (greater than 9 in 10 chances) that global mean sea level (based on mean sea level in 1992) will rise at least 8 inches (0.2 meters) and no more than 6.6 feet (2 meters) by 2100".

Enescot (talk) 12:45, 29 June 2013 (UTC)

PROPOSAL; just omit IPCC AR4 from the image and inclusion of all this more recent work you wish to include will make a great improvement to the article.

DETAILED RESPONSE; Our images have to accurately reflect the source. With respect to our point of disagreement (how to graphically depict IPCC AR 2007 WG1 sea level rise projections), the source to be "reflected" is IPCC AR 2007 WG1. The trouble we're having is that IPCC explicitly said that they were not projecting an upper boundary due in part to what was, at the time, poorly constrained ice sheet behavior.

Your first reference in your last comment appears to deal with the "AR4 no-upper boundary" problem by retroactively calculating an upper boundary. They showed IPCC's numbers, which omitted "rapid dynamical changes in ice flow" and then added what I think is their own number for such rapid changes (17cm). In effect, this image supports my point that we should not just draw out a bar that appears to say IPCC projected an upper boundary at 59cm, because the RSs all agree that is untrue. The way your first reference tried to graphically depict the lack of an upper boundary is not an RS for us to use no approach at all.

Your second link does indeed graphically show IPCC's numbers as though they included an upper boundary for their projection. But the text of that full reference admits "IPCC AR4 estimates did not include, however, potential rapid dynamic response of Greenland and Antarctic Ice Sheets as reflected in our Highest Scenario." So what is this second source an RS for? For one thing, it is an RS for how they dealt with this very problem. But so what? Our rules still say our images have to reasonably represent what is stated in the source. IPCC explicitly refrained from stating an upper boundary on their projection. Even if NOAA did not choose to graphically depict the lack of an upper boundary, if we make a picture of IPCC numbers, we still have to follow our rules, not just blindly endorse NOAA's technical editing decisions.

An up arrow and a question mark is one of the few alternative methods I have suggested. A new idea is to simply omit IPCC from the graphic, and instead deal with IPCC's numbers in text only.

Thanks for caring about adding the more recent research. On the need to do that, I definitely agree!

NewsAndEventsGuy (talk) 12:12, 7 July 2013 (UTC)

I still disagree with your idea of adding arrows to the graph. I also do not agree with your suggestion of omitting the IPCC estimates. The IPCC's estimates are included in both the US NRC and NOAA graphs (figure 9, p.11).

In my opinion, you are placing too much emphasis on the higher end projections of sea level rise. My understanding is that all SLR projections are highly uncertain, including those that project SLR greater than that in AR4. This is discussed in the US NRC and NOAA reports, as well as a literature review by Good et al. For instance, Good et al (p.12) state: "Although there are predictions of sea level rise in excess of IPCC AR4 values, these typically use semi-empirical methods that suffer from limited physical validity".

In my opinion, the NOAA graph (Figure ES 1, p.3) that I suggested previously would be a suitable replacement for the existing graph. It broadly reflects the literature, with each projection assuming a different contribution to SLR from ice sheets. This is discussed in pp.10-14 of the report.

Enescot (talk) 10:04, 9 July 2013 (UTC)

And I am happy to use a modified version of that image, one which includes some manner of graphically depicting IPCC's explicit statement that the largest number in their range did not represent an upper boundary. I am not a graphics guy or I would modify it and post to the article myself. I appreciate your desire to add more recent research to the graph, but not at the expense of an image that casts a false representation of the text in the IPCC RS. Since we've come full circle several times, I would appreciate your taking the next step of DR instead of rehashing the argument for an 7th or 8th time. Even better, maybe others would express an opinion, please? NewsAndEventsGuy (talk) 12:59, 9 July 2013 (UTC)

I haven't read all the above, sorry. My understanding from memory is that the AR4 numbers given in the figure aren't really SLR projections, because they exclude some unknown components [9]. Perhaps they should just be omitted William M. Connolley (talk) 13:20, 9 July 2013 (UTC)

Thanks for joining in and your memory is correct. In my first post in this thread I quoted from where IPCC says they were not projecting an upper boundary. Simply omitting AR4 from the image is also OK with me, but Enescot has (so far) rejected that option. NewsAndEventsGuy (talk) 14:00, 9 July 2013 (UTC)

Omitting AR4 isn't something I'd do lightly, normally its the wrong thing to do. In the case of SLR, though, I think they came in for a certain amount of (justified) stick for omitting important elements. There's also the problem that their estimates are entirely model based - models are fine, of course, but there's a literature on empirical scaling (which some of the other estimates of the figure use, so I'm not complaining that we're ignoring that) which the AR4 ignores. And (although I wouldn't suggest we say this) its clear that the AR4 lower bound is ridiculous - there's no way that anything less than, say, 3mm/yr is believable William M. Connolley (talk) 22:09, 9 July 2013 (UTC)

I think we have our wires crossed. The graph that I've suggested as a replacement (figure 10 on p.12 of the NOAA report) does not include AR4's projections. The projections are by Paris et al, and are based on a literature assessment that includes AR4 projections. The projections by Paris et al range from 0.2-2.0 m by 2100, relative to mean sea level in 1992.

"Our Intermediate-Low [0.5 m] and Lowest Scenarios [0.2 m] are optimistic scenarios of future environmental change assuming rates of ice sheet loss and ocean warming slightly higher or similar to recent observations" – p.13 of report

An alternative would be to have no graph and simply describe projections in text. For example:

"Over the 21st century, the IPCC projects that global mean sea level could rise by 18-59 cm. The IPCC do not provide a best estimate of global mean sea level rise, and their upper estimate of 59 cm is not an upper-bound, i.e., global mean sea level could rise by more than 59 cm by 2100. The IPCC's projections are conservative, and may underestimate future sea level rise [10]. Projections by Paris and others suggest that global mean sea level could rise by 0.2 to 2.0 m by 2100, relative to mean sea level in 1992"

Enescot (talk) 13:25, 16 July 2013 (UTC)

Summary

Thanks for the the back and forth. If I understand correctly, the proposal in this thread has zeroed in on the suggestion to use this image (figure 10 on p.12 of the NOAA report) in place of something. If we do that we will be displaying someone else's graphically misleading IPCC number, but as no one else appears to object, I will at least say this graphic mis-statement softens the misleading impact compared to others we have discussed, so I will probably go along to get along. Before I commit to that, please help me distill the discussion to its essentials. Q1 Remind me please what image you want to take out when this one is put in? Q2 Besides image replacement, are there other open items in this thread? NewsAndEventsGuy (talk) 12:27, 22 July 2013 (UTC)

As I've said, the graph by Paris et al does not include the IPCC's projections. Their low-end projections are their own:

"Our Intermediate-Low [0.5 m] and Lowest Scenarios [0.2 m] are optimistic scenarios of future environmental change assuming rates of ice sheet loss and ocean warming slightly higher or similar to recent observations" – p.13 of report

I do not agree that the graph by Paris et al is misleading. There is nothing unusual about producing projections that span the range in the literature. The IPCC did the same thing when they produced the SRES scenarios.

Q1: The following image would be replaced:

Sea level rise projections for 2100.

I've also suggested an alternative where the graph above would be removed and replaced with the following text:

"Over the 21st century, the IPCC projects that global mean sea level could rise by 18-59 cm. The IPCC do not provide a best estimate of global mean sea level rise, and their upper estimate of 59 cm is not an upper-bound, i.e., global mean sea level could rise by more than 59 cm by 2100. The IPCC's projections are conservative, and may underestimate future sea level rise [22]. Over the 21st century, Paris and others suggest that global mean sea level could rise by 0.2 to 2.0 m, relative to mean sea level in 1992"

Since my last post, I've altered the text above slightly.

Q2: I don't think so.

Enescot (talk) 12:51, 24 July 2013 (UTC)

I can live with the NOAA graph, though I note that the intermediate range NOAA used was simply imported from IPCC ("Our Intermediate-Low Scenario is based on the upper end of IPCC Fourth Assessment Report (AR4) global SLR projections resulting from climate models using the B1 emissions scenarios." NOAA report, p 12). In so doing NOAA blatantly ignored IPCC's explicit statement that it was not to be used as an upper bound, nor a best estimate. While I agree that it is common to summarize the range of the literature, I remain steadfast in my belief that it is uncommon and improper to summarize it falsely, which is what people do when they say or imply IPCC projected only around 59cm +/-, as though that were an IPCC AR4 best estimate or IPCC AR4 upper boundary, because that is misrepresentation of what IPCC AR4 said. NOAA made that error. Using this graph we import that error, but in a blunted way with which I can live if it is only you and me trying to resolve this. NewsAndEventsGuy (talk) 18:44, 24 July 2013 (UTC)

I don't agree with your criticism of the NOAA report. Their scenarios are intended for the purposes of risk assessment. The authors of the report state that "specific probabilities or likelihoods are not assigned to individual scenarios in this report, and none of these scenarios should be used in isolation" (p.1).

My suggested revision is below. New text is in italics. I haven't uploaded the NOAA graph yet:

"... declines in Arctic sea ice extent, and to glacier retreat.[132]

[NOAA graph. Caption: Projections of global mean sea level rise by Paris and others. None of these scenarios is a best estimate of future sea level rise.]

[new text] Over the 21st century, the IPCC projects that global mean sea level could rise by 18-59 cm. The IPCC do not provide a best estimate of global mean sea level rise, and their upper estimate of 59 cm is not an upper-bound, i.e., global mean sea level could rise by more than 59 cm by 2100. The IPCC's projections are conservative, and may underestimate future sea level rise [22]. Over the 21st century, Paris and others suggest that global mean sea level could rise by 0.2 to 2.0 m, relative to mean sea level in 1992 (refer to graph opposite)

On the timescale of centuries to millennia, the melting of..."

Enescot (talk) 13:47, 31 July 2013 (UTC)

Reconsidering.... If I understand right, your proposed RS (a 2012 NOAA report, see link under the subsection heading above) includes a "low" value for sea level rise based on ice sheet behavior holding steady and past SLR rates holding steady, to yield what even the authors called an "optimistic" low-end projection 20cm above 1992 levels. ins>Besides Enescot does anyone think 20cm on top of 1992 levels reflects the bulk of the literature for low estimates? For one thing, see this press coverage of a new PNAS paper. To be fair, I haven't seen the original PNAS paper, and I don't know if they discuss low estimates. I'd just like to know what those more knowledgeable than myself have seen in other current RSs for low projections? NewsAndEventsGuy (talk) 16:40, 31 July 2013 (UTC)

Since no one else has climbed on board, I defer to the silence and change my "object" to "no contest". Go ahead and make your desired change Enescot (talk · contribs), and I will renew my objection, maybe, if the edit inspires other resistance. Thanks for your patience during an extended yet constructive back and forth. NewsAndEventsGuy (talk) 22:58, 4 August 2013 (UTC)

Thanks for the feedback. I'd just like to further respond to some of your comments. I have never suggested that slr of 20 cm is reflective of recent low estimates. I have said that the range of 0.2-2.0 m is comparable to the range in the literature. This is explained in the NOAA report. The IPCC's estimates were subject to a very rigorous process of review, so they are robust estimates. My suggested revision includes the IPCC's own caveats, as well as the more recent comment by the US NRC: "The IPCC's projections are conservative, and may underestimate future sea level rise [11]".

I've previously referred to a review by Good et al (p.12), which states that: "Although there are predictions of sea level rise in excess of IPCC AR4 values, these typically use semi-empirical methods that suffer from limited physical validity"

I believe that this is the relevant PNAS paper [12], which I obtained from [13]. I haven't fully read the paper, but it seems to focus on long-term, multi-century estimates of slr.

The existing revision of the article does mention long-term slr, but it could be improved. At present, it does not mention the commitment to slr from thermal expansion alone. I've put together a draft revision based on US NRC (2011):

"Widespread coastal flooding would be expected if several degrees of warming is sustained for millennia. 2 C of warming (relative to pre-industrial levels) could lead to eventual sea level rise of around 1 to 4 m due to thermal expansion of sea water and the melting of glaciers and small ice caps. Melting of the Greenland ice sheet could contribute an additional 4 to 7.5 m over many thousands of years."

Enescot (talk) 12:05, 6 August 2013 (UTC)

Better and more pictures showing also the temperature scale inside and time frame before

Lots of images interfering with page readability. Click to show.

NASA Global warming map showing main warming at northern hemisphere with most warming at arctis area with +2° and that is not explainable with greenhouse gases but streaming changes and also the base time frame not same comaprison time frame isn´t secured with satellite datas expleining also the difference between NASA-Goddard +0.73° & WMO/UNO +0.53° for middle value Global warming map Global cooling map 1965-1975 vs 1937-1946 Antarctica temps 1957-2006 showing warm up Antarctica temps 1982-2004 showing cool down Arctis ice map for 2008 and 2006 showing much ice left and swimming ice is not inreasing the sea level if molten just the greenland ice shield could increase molten 6-7m but was just rising about +0.2mm/a means just 2cm in 100 years so it`s not dangerous because before to much molten CO2 sources are out and next ice time there and also there was much more temperature increase already than the global middle value increase means on more increese of middle value unclear any more increase there because of different reasons and also polar bears prefere warmer climate there & increased in number near forefold already Methane Map 2011 shows more methane in northern hemisphere but much too less difference for temperature difference explanation NASA Methane Map showing high equatorial methane level in stratosphere carried up by up wind there at sahara desertification area since 1970 and surface near methane increase also in aral sea desertification area NASA CO2 Map mid tropospheric (8km) from July 2003 AIRS map showing CO2 high in northern hemisphere but much too less for explanation of temperature differences

New paragraph about travel-related emissions

In this well-written and good faith series of edits, Watti Renew (talk · contribs) added a paragraph on GHG emissions related to travel. It is well sourced, but travel is just one slice of the emissions pie. I propose this paragraph be relocated to a sub article focused on GHGs or emission sources or mitigation (or a combination). We should talk about the biggest slices of the pie in a few sentences and have an overview paragraph that briefly reviews the colleciton of smaller slices for navigation purposes.

Anyone else have an opinion? NewsAndEventsGuy (talk) 17:13, 23 July 2013 (UTC)

I agree with you. I've moved the information to greenhouse gas#Sectors. Enescot (talk) 12:24, 24 July 2013 (UTC)

FYI, Important discussion about use of POV tags

Posting at this top level GW article to call the attention to all users, of whatever persuasion on this issue....

Since we all sometimes want to add, or remove, POV tags from this tree of articles, please take a moment to visit this important discussion about whether we can remove the POV tag when any discussion has long been dormant. NewsAndEventsGuy (talk) 19:01, 25 July 2013 (UTC)

Some charts are really old

144.160.226.53 posted this comment on 28 May 2013 (view all feedback).

Charts Outdated==

Some charts are really old with data only up to 2004, so almost 10 years old - for this topic there should be newer, current data available. It's especially interesting to see the current development over the past few years; this is really crucial and I'm sure the data is available...

Any thoughts?

We should Update charts

Austin56713 12:40, 26 July 2013 (UTC) — Preceding unsigned comment added by Austin56713 (talk • contribs)

Is this a good chart blue line represents average:

http://www.globalsherpa.org/wp-content/uploads/2012/12/noaa-global-warming-mean-temperature-graph-jan-dec.gif — Preceding unsigned comment added by Austin56713 (talk • contribs) 12:49, 26 July 2013 (UTC)

I agree that some of the charts could be updated. The lead section of the article already contains an up-to-date graph of global mean temperature. I have some more recent data on Earth's energy imbalance [14]. I also know of some other sources of more recent data (e.g., of greenhouse gas emissions by sector and cumulative CO2 emissions by region) but I'll have to dig around for these. Enescot (talk) 12:42, 13 August 2013 (UTC)

New paper in Energy & Environment

This should be added to the article:

http://www.climatedepot.com/2013/08/02/new-satellite-dataset-finds-global-temperatures-decreased-from-1982-2006/

New satellite dataset finds global temperatures decreased from 1982-2006

A new peer-reviewed paper published in Energy & Environment analyzes 24 years of data from the European Meteosat weather satellite and finds global temperatures decreased over the period 1982-2006.

CQ 126 (talk) 03:54, 4 August 2013 (UTC)

Big claims need big evidence and this journal has a reputation for very low standards. This means see FAQ 21 not once but twice. NewsAndEventsGuy (talk) 07:35, 4 August 2013 (UTC)

Linking to climatedepot isn't a good sign. The paper itself is interesting, but probably wrong. Meta-analysis: its published in E&E. If it was any good, it wouldn't be. Slightly less meta: they make no attempt to reconcile their results to either the satellite record, or the surface record (the latter would be more appropriate, since they produce a sfc record). Closer: they don't pay much attention to long-term calibration; and since clouds are such a vital part of this, they're remarkably brief about their cloud-clearing algorithm. And apart from all else, we should certainly not add it now; its too new William M. Connolley (talk) 08:51, 4 August 2013 (UTC)

Agree with NewsAndEventsGuy & William M. Connolley. The article itself is poor, it contradicts pretty much every other article on the subject and it's printed in a low quality magazine edited by a known denier. Extraordinary claims require extraordinary proof. Regards. Gaba ^(talk) 17:27, 4 August 2013 (UTC)

Attribution AGW to nuclear & geothermal heat sources

This thread fails to cite any RSs or suggest improvements based on them, in contradiction of WP:NOTFORUM. Click show to read anyway

Many sources consider Nuclear Electrical Power Generation and Geothermal Heating as NOT contributing to Global Warming. Maybe, indirectly? Do not Nuclear Reactors intensify and increase the rate of exothermic decay of their fuel? They also depend on the ancient Rankine System Steam cycle. Two thirds of the heat is dumped into the environment directly - and all eventually(?). Does not Geothermal Heating increase the rate of heat transfer from the Earth's Core to the Atmosphere (eventually)? Thus all of this excess heat has to be dissipated by radiant cooling from the earth. The main benefit from these energy alternatives is the amount of GHG's that they displace, thus improving the earth's ability to rid itself of the excess heat (or heat transfer)- some of which they are responsible for. Then again there would probably have to be a great deal more geothermal heating to compete with an active volcano season? Pete318 (talk) 18:38, 6 August 2013 (UTC) Essentially this is an issue for the Climate change mitigation article which is briefly summarised in this article. I have not gone into this topic, but would understand that nuclear and geothermal cause some GHG addition: for example, steel and concrete are both carbon intensive. In the longer run they can replace fossil fuels, which are the main contribution to global warming. In my limited understanding, the actual heat contribution is relatively small. Anyway, the topic is covered in this main article, appropriately briefly. If you find good reliable sources which support significant change, they should first be used to update the sub-article. . dave souza, talk 19:36, 6 August 2013 (UTC) (edit conflict)Waste heat is much much smaller than heat trapped by CO2 over long time scales, but comparable over short timescales . this study finds that the annual global heating from waste heat from coal power plants is roughly equivalent to the heating caused by CO2 over that year. However, over the long term (fifty years of operation plus fifty years afterwards) the CO2 proviles 92% of the warming. Think of it like this. In year one, waste heat and CO2 each add one unit. In year 2, waste heat adds one unit, but CO2 adds two units because the first unit of CO2 is still trapping heat. At three years, it's 3 units from CO2 vs. one from waste heat, etc., etc. And then once the plant goes offline most of that CO2 is still contributing to heating the planet! Nuke plants are comparable in waste heat to coal plants (maybe a bit more) but have zero from CO2 so overall nuclear "wins" in terms of limiting global warming. This is a good question though, and the study I linked here might be worth putting into our articles somewhere, because the information wasn't easy to find with real numbers. Sailsbystars (talk) 19:38, 6 August 2013 (UTC) Agree with Dave and Sails NewsAndEventsGuy (talk) 19:41, 6 August 2013 (UTC) I did some calculations a long time ago: http://mustelid.blogspot.co.uk/2005/04/global-warming-is-not-from-waste-heat.html William M. Connolley (talk) 09:04, 7 August 2013 (UTC) As I understand the matter..... (bear with me for a minute with my simplifications).... Global Warming is a matter of planetary heat transfer. Climate change is largely a secondary consequence. Solar energy in > energy stored in energy sinks > heat released from energy sinks > heat radiated from the planet. Carbon enters the equation two ways: (1)carbon based greenhouse gases released to the atmosphere changes the radient/thermal properties of the atmosphere lessening the ability of the planet to cool AND (2) by releasing not only stored energy but stored carbon from fossil fuel sinks. Extensive (to be quantified) Geothermal energy systems increase the rate of heat transfer from one of the thermal sinks - the molten core of the planet. Nuclear power, as I understand the process, accelerates and concentrates the rate of decay with a natural ore/fuel. It contributes to Global Warming and hence Climate Change arising from that phenomena by (a) the greenhouse gases emitted by the manufacturing, construction and maintainance activities associated with power stations AND (b) increasing the rate of heat from a controlled nuclear reaction. The theory is that all energy generated from a power plant ends up in the environment directly or indirectly eventually. Waste heat from steam cycles contribute much more immediately. Global Warming could be a problem without an increase in CO2 if the Earth's Core cooled faster (more volcanic activity) or all of our energy came from nuclear powered steam systems. The CO2 from fossil fuel Power Plants complicates matters by inhibiting the thermal cooling properties of the planet. The fact that society is burning and metabolizing too much carbon is one matter, the increasing amount of energy that an increasing population is using since the industrial revolution is another. A caption for a photograph from the Wiki Article "Nuclear Power" states: "....Unlike fossil fuel power plants, the only substance leaving the cooling towers of nuclear power plants is water vapour and thus does not pollute the air or cause global warming.....". First, water vapour (the vapour condensate is the visible emission from a cooling tower) is a greenhouse gas - albeit a mild one. The condensing vapour adds to the heat load of the atmosphere. It all has to be radiated from the earth sometime. Nuclear Power Plants contribute much less to greenhouse gas emissions, but do contribute (IMHO) to global warming. Does the former offset the latter - a difficult perspective to quantify? These cooling towers that emit H2O may contribute to cloud formation and reflect some incoming solar radiation, but I suspect that this is also difficult to quantify. I don't mean to clutter this Talk page, but why clutter the the others (Climate Change Mitigation, Nuclear Power etc.) as well. maybe the matter can be sorted out here - if need be at all? Pete318 (talk) 18:26, 8 August 2013 (UTC) No, I think dave souza, Sailsbystars, NewsAndEventsGuy and William M. Connolley had it about right. This latest post, Pete318, is full of muddles and strange ideas that don't fit in with normal usage of the terms, or are not consistent with the scientific literature on the subjects. This isn't a help desk, so there are too many points to go through them in detail here. Suffice to say that if any of this was relevant to improving the article, it would have to be accompanied by an impressive list of new references that say it is. --Nigelj (talk) 22:22, 8 August 2013 (UTC) The Talk page is not the Article - a discussion of the logic of the content is not out of place. I enjoy the criticism but comments such as ".....muddles and strange ideas that don't fit in with normal usage of the terms, or are not consistent with the scientific literature on the subjects......" do not address ANY of the points and makes no contribution whatever and clutters the page even more. If there are several points - pick just one at a time? Help Desk???? - Please! Nothing worse than Academic trash talking - delete the entire section and I will discuss elsewhere. Pete318 (talk) 22:42, 8 August 2013 (UTC) For closure....? from [15] Hi, In reply to your comments at TALK:Global warming, the talk page is not an acceptable place for a general discussion of the topic. See WP:NOTFORUM. Instead we have specific talk page guidelines that say article talk pages are for exploring specific ideas to improve articles on the basis of what wikipedia definese as reliable sources. I agree with Nigelj's feedback posted after your comment at the article talk page. NewsAndEventsGuy (talk) 22:51, 8 August 2013 (UTC) A reliable source means more than just a footnote. The citer has to quote the article and discuss the logic of the content. These days, it seems, many contributers appear to just search the internet and find some page or ".pdf" document that agrees with their point and appears credible. In the old days when a publisher would plan for a printing of a text - especially an encyclopedia - the investor would have to set aside a great deal of money before printing. Whether the content was biased or reliable or not, at least the editors had to make sure that it was exactly what they wanted to say - spelling, syntax and grammer included. Many readers may not follow the logic behind the text anyway - make it readable to as many as possible - sell the books! Wiki - aims(?) to do this but how can it without discussion. The Talk Page is the only utility that facilitates this - rules or not? All of my comments were thought out and challenged the logic of the section of the article. "Green" sources of energy may not contribute to Greenhouses Gases in the atmosphere but do(apparently) artifically generate more heat transfer which, logically, would contribute to global warming - not as much a those that produce CO2 as well (obviously! - footnote or not) but still some. If my logic had any basis, then say - politely - ".... interesting point Pete318 - can you track down a specific reference for that point. Check back maybe another poster can find one...." The rebuttal comment was simply ignorant. If the poster had actually read it he/she may have noted - "....that the caption cited from the Nuclear Power article is not referenced!!! and - horrors - it is in the ARTICLE not the TALK Page!!!.....". Most of my other points come from standard principles in textbooks, but it is a discussion of logic. This ("your"(plural)) page has a flaw in logic with both the Geothermal and Nuclear Power context! Thank you for taking the time to politely reply. However I am learning from my experience with wiki that logic is not absolute. If a participant becomes abrupt or rude that is worse than being them being inaccurate - bail out of the Talk page! Nice of you, but you cannot repair the insult by proxy. Let the posters jealous of their cyper-turf have their day. He/she probably meant no offence, none taken - just annoyed. Thanks again. [Maybe have a new format: ARTICLE TALK FORUM - go to a forum with your point first - if it makes it past there go to Talk with the cited details - then agree on the ARTICLE content?] Pete318 (talk) 18:18, 9 August 2013 (UTC) Pete318 (talk) 18:23, 9 August 2013 (UTC)

Rudyfoto links are broken.

The links get a 500 server error, and have been doing so since March. Should the links to them in the FAQ be removed? Sorry if this has already been discussed. 74.128.43.180 (talk) 18:44, 13 August 2013 (UTC)