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Frequently asked questions

To view an answer, click the [show] link to the right of the question. To view references used by an answer, you must also click the [show] for references at the bottom of the FAQ.

Q1: Is there really a scientific consensus on climate change?

A1: Yes. The IPCC findings of recent warming as a result of human influence are explicitly recognized as the "consensus" scientific view by the science academies of all the major industrialized countries. No scientific body of national or international standing presently rejects the basic findings of human influence on recent climate. This scientific consensus is supported by over 99% of publishing climate scientists.^[1]

Q2: How can we say climate change is real when it's been so cold in such-and-such a place?

A2: This is why it is termed "global warming", not "(such-and-such a place) warming". Even then, what rises is the average temperature over time – that is, the temperature will fluctuate up and down within the overall rising trend. To give an idea of the relevant time scales, the standard averaging period specified by the World Meteorological Organisation (WMO) is 30 years. Accordingly, the WMO defines climate change as "a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer)."^[2]

Q3: Can't the increase of CO₂ be from natural sources, like volcanoes or the oceans?

A3: While these claims are popular among global warming skeptics,^[3]^[4] including academically trained ones,^[5]^[6] they are incorrect. This is known from any of several perspectives:

Current human emissions of CO₂ are at least 100 times larger than volcanic emissions. Measurements of CO₂ levels over the past 50 years do not show any significant rises after eruptions.^[7] This is easily seen in a graph of CO₂ concentrations over the past 50 years: the strongest eruption during the period, that of Mount Pinatubo in 1991, produced no increase in the trend.
Isotopic analysis of atmospheric carbon dioxide shows the observed change in the ratio of carbon isotopes reflects the isotopic ratios in fossil fuels.^[8]
Atmospheric oxygen content is decreasing at a rate that agrees with the amount of oxygen being used to burn fossil fuels.^[9]
If the oceans were giving up some of their carbon dioxide, their carbon dioxide concentration would have to decrease. But instead we are measuring an increase in the oceans' carbon dioxide concentration, resulting in the oceans becoming more acidic (or in other words, less basic).^[10]

Q4: I think the article is missing some things, or has some things wrong. Can I change it?

A4: Yes. Keep in mind that your points need to be based on documented evidence from the peer-reviewed literature, or other information that meets standards of verifiability, reliability, and no original research. If you do not have such evidence, more experienced editors may be able to help you find it (or confirm that such evidence does not exist). You are welcome to make such queries on the article's talk page but please keep in mind that the talk page is for discussing improvements to the article, not discussing the topic. There are many forums that welcome general discussions of global warming, but the article talk page is not such a forum.

Q5: Why haven't the graphs been updated?

A5: Two reasons:

There are many images used in the articles related to global warming, and there are many reasons why they may not be updated with the latest data. Some of the figures, like the Global Warming Map, are static, meaning that they are intended to show a particular phenomenon and are not meant to be updated frequently or at all. Others, like the Instrumental Temperature Record and Northern Hemisphere Sea Ice Extent Anomalies, use yearly data and thus are updated once per year—usually in mid- to late-January, depending upon when the data is publicly released, and when a volunteer creates the image. Still others, like Mauna Loa Carbon Dioxide, use monthly data. These are updated semi-regularly.
However, just because an image is 6 months or a year old does not mean it is useless. Robert A. Heinlein is credited with saying, "Climate is what you expect, weather is what you get", meaning that climate is defined as a long-term average of weather, usually about 30 years. This length was chosen to eliminate the year-to-year variations.^[11] Thus, in terms of climate change, any given year's data is of little import.

Q6: Isn't climate change "just a theory"?

A6: People who say this are abusing the word "theory" by conflating its common meaning with its scientific meaning. In common usage, "theory" can mean a hunch or guess, but a scientific theory, roughly speaking, means a coherent set of explanations that is compatible with observations and that allows predictions to be made. That the temperature is rising is an observation. An explanation for this (also known as a hypothesis) is that the warming is primarily driven by greenhouse gases (such as CO₂ and methane) released into the atmosphere by human activity. Scientific models have been built that predict the rise in temperature and these predictions have matched observations. When scientists gain confidence in a hypothesis because it matches observation and has survived intense scrutiny, the hypothesis may be called a "theory". Strictly speaking, scientific theories are never proven, but the degree of confidence in a theory can be discussed. The scientific models now suggest that it is "extremely likely" (>95%) to "virtually certain" (>99%) that the increases in temperature have been caused by human activity as discussed in the IPCC Fifth Assessment Report. Global warming via greenhouse gases by human activity is a theory (in the scientific sense), but it is most definitely not just a hunch or guess.

Q7: Does methane cause more warming than CO₂?

A7: It's true that methane is more potent molecule for molecule. But there's far less of it in the atmosphere, so the total effect is smaller. The atmospheric lifetime of methane (about 10 years) is a lot shorter than that of CO₂ (hundreds to thousands of years), so when methane emissions are reduced the concentration in the atmosphere soon falls, whereas CO₂ accumulates in the atmosphere over long periods. For details see the greenhouse gas and global warming potential articles.

Q8: How can you say there's a consensus when lists of "skeptical scientists" have been compiled?

A8: Consensus is not the same as unanimity, the latter of which is impractical for large groups. Over 99% of publishing climate scientists agree on anthropogenic climate change.^[1] This is an extremely high percentage well past any reasonable threshold for consensus. Any list of "skeptical scientists" would be dwarfed by a comparably compiled list of scientists accepting anthropogenic climate change.

Q9: Did climate change end in 1998?

A9: One of the strongest El Niño events in the instrumental record occurred during late 1997 through 1998, causing a spike in global temperature for 1998. Through the mid-late 2000s this abnormally warm year could be chosen as the starting point for comparisons with later years in order to produce a cooling trend; choosing any other year in the 20th century produced a warming trend. This no longer holds since the mean global temperatures in 2005, 2010, 2014, 2015 and 2016 have all been warmer than 1998.^[12] More importantly, scientists do not define a "trend" by looking at the difference between two given years. Instead they use methods such as linear regression that take into account all the values in a series of data. The World Meteorological Organisation specifies 30 years as the standard averaging period for climate statistics so that year-to-year fluctuations are averaged out;^[2] thus, 10 years isn't long enough to detect a climate trend.

Q10: Wasn't Greenland much warmer during the period of Norse settlement?

A10: Some people assume this because of the island's name. In fact the Saga of Erik the Red tells us Erik named the new colony Greenland because "men will desire much the more to go there if the land has a good name."^[13] Advertising hype was alive and well in 985 AD.

While much of Greenland was and remains under a large ice sheet, the areas of Greenland that were settled by the Norse were coastal areas with fjords that, to this day, remain quite green. You can see the following images for reference:

A map of the Eastern Settlement
A satellite image of that area today
A map of the Western Settlement
A satellite image of that area today
A zoom in on the general area where the Brattahlíð (Erik the Red's farm) and Garðar farms were located

Q11: Are the IPCC reports prepared by biased UN scientists?

A11: The IPCC reports are not produced by "UN scientists". The IPCC does not employ the scientists who generate the reports, and it has no control over them. The scientists are internationally recognized experts, most with a long history of successful research in the field. They are employed by various organizations including scientific research institutes, agencies like NASA and NOAA, and universities. They receive no extra pay for their participation in the IPCC process, which is considered a normal part of their academic duties.

Q12: Hasn't global sea ice increased over the last 30 years?

A12: Measurements show that it has not.^[14] Claims that global sea ice amounts have stayed the same or increased are a result of cherry picking two data points to compare, while ignoring the real (strongly statistically significant) downward trend in measurements of global sea ice amounts.

Arctic sea ice cover is declining strongly; Antarctic sea ice cover has had some much smaller increases, though it may or may not be thinning, and the Southern Ocean is warming. The net global ice-cover trend is clearly downwards.

Q13: Weren't scientists telling us in the 1970s that the Earth was cooling instead of warming?

A13: They weren't – see the article on global cooling. An article in the Bulletin of the American Meteorological Society has reviewed the scientific literature at that time and found that even during the 1970s the prevailing scientific concern was over warming.^[15] The common misperception that cooling was the main concern during the 1970s arose from a few studies that were sensationalized in the popular press, such as a short nine-paragraph article that appeared in Newsweek in 1975.^[16] (Newsweek eventually apologized for having misrepresented the state of the science in the 1970s.)^[17] The author of that article has repudiated the idea that it should be used to deny global warming.^[18]

Q14: Doesn't water vapour cause 98% of the greenhouse effect?

A14: Water vapour is indeed a major greenhouse gas, contributing about 36% to 70% (not 98%) of the total greenhouse effect. But water vapour has a very short atmospheric lifetime (about 10 days), compared with decades to centuries for greenhouse gases like CO₂ or nitrous oxide. As a result it is very nearly in a dynamic equilibrium in the atmosphere, which globally maintains a nearly constant relative humidity. In simpler terms, any excess water vapour is removed by rainfall, and any deficit of water vapour is replenished by evaporation from the Earth's surface, which literally has oceans of water. Thus water vapour cannot act as a driver of climate change.

Rising temperatures caused by the long-lived greenhouse gases will however allow the atmosphere to hold more vapour. This will lead to an increase in the absolute amount of water vapour in the atmosphere. Since water vapour is itself a greenhouse gas, this is an example of a positive feedback. Thus, whereas water vapour is not a driver of climate change, it amplifies existing trends.

Q15: Is the fact that other solar system bodies are warming evidence for a common cause (i.e. the sun)?

A15: While some solar system bodies show evidence of local or global climate change, there is no evidence for a common cause of warming.

A 2007 National Geographic article described the views of Khabibullo Abdusamatov, who claims that the sun is responsible for global warming on both Earth and Mars.^[19] Abdussamatov's views have no support in the scientific community, as the second page of the National Geographic article makes clear: "'His views are completely at odds with the mainstream scientific opinion,' said Colin Wilson, a planetary physicist at England's Oxford University. [...] Amato Evan, a climate scientist at the University of Wisconsin, Madison, added that 'the idea just isn't supported by the theory or by the observations.'"^[20]
There is no reliable source claiming that Jupiter is warming. However, observations of the Red Spot Jr. storm suggest Jupiter could be in a period of global climate change.^[21]^[22] This is hypothesized to be part of an approximately 70 year global climate cycle, characterized by the relatively rapid forming and subsequent slow erosion and merging of cyclonic and anticyclonic vortices that help transfer heat between Jupiter's poles and equator. The cycle works like this: As the vortices erode, heat exchange is reduced; this makes the poles cool down and the equatorial region heat up; the resulting temperature difference destabilizes the atmosphere, leading to the creation of new vortices.^[23]^[24]
Pluto has an extremely elliptical orbit with a period of about 248 years. Data are sparse, but two data points from 1988 and 2002 indirectly suggest that Pluto warmed between those two dates.^[25] Pluto's temperature is heavily influenced by its elliptical orbit – it was closest to the sun in 1989 and has slowly receded since. Because of thermal inertia, it is expected to warm for a while after it passes perihelion (similar to how a sunny day's warmest temperatures happen during the afternoon instead of right at noon). No other mechanism has so far been seriously suggested. Here is a reasonable summary, and this paper discusses how the thermal inertia is provided by sublimation and evaporation of parts of Pluto's atmosphere. A more popular account is here and in Wikipedia's own article.

Q16: Do scientists support climate change just to get more money?

A16: No,

Scientists participate in international organizations like the IPCC as part of their normal academic duties. They do not receive any extra compensation beyond possibly for direct expenses.
Scientific grants do not usually award any money to a scientist personally, only towards the cost of his or her scientific work.
There is not a shortage of useful things that scientists could study if they were not studying global warming.
- Understanding our climate system better brings benefits independent of global warming. For instance, more accurate weather predictions save a lot of money (on the order of billions of dollars a year), and everyone from insurance agents to farmers wants climate data.^[26]^[27] Scientists could get paid to study climate even if global warming did not exist.

Q17: Doesn't the climate vary even without human activity?

A17: It does, but the fact that natural variation occurs does not mean that human-induced change cannot also occur. Climate scientists have extensively studied natural causes of climate change (such as orbital changes, volcanism, and solar variation) and have ruled them out as an explanation for the current temperature increase. Human activity is the cause at the 95 to 99 percent confidence level (see the IPCC Fifth Assessment Report for details). The high level of certainty in this is important to keep in mind to spot mention of natural variation functioning as a distraction.

Q18: Should we include the view that climate change will lead to planetary doom or catastrophe?

A18: This page is about the science of climate change. It doesn't talk about planetary doom or catastrophe. For a technical explanation, see catastrophic climate change, and for paleoclimatic examples see PETM and great dying.

Q19: Is an increase in global temperature of, say, 3 degrees Celsius (5.4 degrees Fahrenheit) important?

A19: Though it may not sound like much, a global temperature rise of 3 degrees Celsius (5.4 degrees Fahrenheit) is huge in climate terms. For example, the sea level rise it would produce would flood coastal cities around the world, which include most large cities.

Earth's climate has varied significantly over geological ages. The question of an "optimal temperature" makes no sense without a clear optimality criterion. Over geological time spans, ecosystems adapt to climate variations. But global climate variations during the development of human civilization (i.e. the past 12,000 years) have been remarkably small. Human civilization is highly adapted to the current stable climate. Agricultural production depends on the proper combination of soil, climate, methods, and seeds. Most large cities are located on the coast, and any significant change in sea level would strongly affect them. Migration of humans and ecosystems is limited by political borders and existing land use. In short, the main problem is not the higher absolute temperature but the massive and unprecedentedly fast change in climate and the related effects on human societies. The IPCC AR6 WG2 report has a detailed discussion of the effects of rapid climate change.

Q20: Why are certain proposals to change the article discarded, deleted, or ignored? Who is/was Scibaby?

A20: Scibaby is/was a long term abusive sock-master (or coordinated group of sock masters) who has created 1,027 confirmed sock puppets, another 167 suspected socks, and probably many untagged or unrecognized ones. This page lists some recent creations. His modus operandi has changed over time, but includes proposing reasonably worded additions on the talk page that only on close examination turn out to be irrelevant, misinterpreted, or give undue weight to certain aspects. Scibaby is banned, and Scibaby socks are blocked as soon as they are identified. Some editors silently revert his additions, per WP:DENY, while others still assume good faith even for likely socks and engage them.

Q21: What about this really interesting recent peer-reviewed paper I read or read about, that says...?

A21: There are hundreds of peer-reviewed papers published every month in respected scientific journals such as Geophysical Research Letters, the Journal of Climate, and others. We can't include all of them, but the article does include references to individual papers where there is consensus that they best represent the state of the relevant science. This is in accordance with the "due weight" principle (WP:WEIGHT) of the Neutral point of view policy and the "Wikipedia is not an indiscriminate collection of information" principle (WP:IINFO) of the What Wikipedia is not policy.

Q22: Why does the article define "climate change" as a recent phenomenon? Hasn't the planet warmed and cooled before?

A22: Yes, the planet has warmed and cooled before. However, the term "climate change" without further qualification is widely understood to refer to the recent episode and often explicitly connected with the greenhouse effect. Per WP:COMMONNAME, we use the term in this most common meaning. The article Climate variability and change deals with the more general concept.

Q23: Did the CERN CLOUD experiment prove that climate change is caused not by human activity but by cosmic rays?

A23: No. For cosmic rays to be causing global warming, all of the following would have to be true, whereas only the italicized one was tested in the 2011 experiment:^[28]

Solar magnetic field must be getting stronger
The number of cosmic rays reaching Earth must be dropping
Cosmic rays must successfully seed clouds, which requires:

Cosmic rays must trigger aerosol (liquid droplet) formation,
These newly-formed aerosols must grow sufficiently through condensation to form cloud-condensation nuclei (CCN),
The CCN must lead to increased cloud formation, and
Cloud cover on Earth must be declining.

Perhaps the study's lead author, Jasper Kirkby, put it best: "...it [the experiment] actually says nothing about a possible cosmic-ray effect on clouds and climate, but it's a very important first step."^[29]

Q24: I read that something can't fix climate change. Is this true?

A24: Yes, this is true for all plausible single things including: "electric cars", "planting trees", "low-carbon technology", "renewable energy", "Australia", "capitalism", "the doom & gloom approach", "a Ph.D. in thermodynamics". Note that it is problematic to use the word "fix" regarding climate change, as returning the climate to its pre-industrial state currently appears to be feasible only over a timeframe of thousands of years. Current efforts are instead aimed at mitigating (meaning limiting) climate change. Mitigation is strived for through the combination of many different things. See Climate change mitigation for details.

References

^ ^a ^b Powell, James (20 November 2019). "Scientists Reach 100% Consensus on Anthropogenic Global Warming". Bulletin of Science, Technology & Society. 37 (4): 183–184. doi:10.1177/0270467619886266. S2CID 213454806. Retrieved 15 November 2020.
^ ^a ^b "Commission for Climatology Frequently Asked Questions". World Meteorological Organization. Archived from the original on 5 May 2020. Retrieved 14 July 2020.
^ Harris, Tom. "Scientists who work in the fields liberal arts graduate Al Gore wanders through contradict his theories about man-induced climate change". National Post. Archived from the original on 30 August 2011. Retrieved 11 January 2009 – via Solid Waste & Recycling. {{cite web}}: |archive-date= / |archive-url= timestamp mismatch; 4 February 2012 suggested (help)
^ Arriola, Benj. "5 Good Arguments Why GlobalWarming is NOT due to Man-made Carbon Dioxide". Global Warming Awareness Blog. Retrieved 11 January 2009.
^ Ahlbeck, Jarl. "Increase of the Atmospheric Carbon Dioxide Concentration due to Ocean Warming". Retrieved 11 January 2009.
^ Kirby, Simon (11 April 2007). "Top scientist debunks global warming". Herald Sun. Retrieved 11 January 2009.
^ Brahic, Catherine (16 May 2007). "Climate myths: Human CO2 emissions are too tiny to matter". New Scientist. Retrieved 11 January 2009.
^ "More Notes on Global Warming". Physics Today. May 2005. Retrieved 10 September 2007.
^ Battle, M.; et al. (2000). "Global Carbon Sinks and Their Variability Inferred from Atmospheric O2 and d13C". Science. 287 (5462): 2467–2470. doi:10.1126/science.287.5462.2467.
^ The Royal Society (2005). "Ocean acidification due to increasing atmospheric carbon dioxide". Retrieved 9 May 2012.
^ "Met Office: Climate averages". Met Office. Archived from the original on 24 February 2009. Retrieved 23 January 2009.
^ Climate Central (18 January 2017). "2016 Was the Hottest Year on Record". Climate Central. Retrieved 1 February 2017.
^ The Saga of Erik the Red, 1880, English translation by J. Sephton, from the original Eiríks saga rauða.
^ "Cold Hard Facts". Tamino. 8 January 2009. Retrieved 21 January 2009.^{[dead link‍]}
^ Peterson, T. C.; et al. (2008). "The Myth of the 1970s Global Cooling Scientific Consensus". Bulletin of the American Meteorological Society. 89 (9): 1325. Bibcode:2008BAMS...89.1325P. doi:10.1175/2008BAMS2370.1.
^ Gwynne, Peter (28 April 1975). "The Cooling World". Newsweek. p. 64.
^ Verger, Rob (23 May 2014). "Newsweek Rewind: Debunking Global Cooling". Newsweek.
^ Gwynne, Peter (21 May 2014). "My 1975 'Cooling World' Story Doesn't Make Today's Climate Scientists Wrong". insidescience.org.
^ Ravilious, Kate (28 February 2007). "Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says". National Geographic News. Archived from the original on 2 March 2007. Retrieved 6 March 2008.
^ Ravilious, Kate (28 February 2007). "Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says (page 2)". National Geographic News. Archived from the original on 2 March 2007. Retrieved 6 March 2008.
^ Marcus, Philip; Shetty, Sushil; Asay-Davis, Xylar (November 2006). Velocities and Temperatures of Jupiter's Great Red Spot and the New Red Oval and Implications for Global Climate Change. American Physical Society. Retrieved 9 May 2007.
^ Goudarzi, Sara (4 May 2006). "New Storm on Jupiter Hints at Climate Change". Space.com. Retrieved 9 May 2007.
^ Philip, Marcus S. (22 April 2004). "Prediction of a global climate change on Jupiter" (PDF). Nature. 428 (6985): 828–831. Retrieved 9 May 2007.
^ Yang, Sarah (21 April 2004). "Researcher predicts global climate change on Jupiter as giant planet's spots disappear". University of California, Berkeley. Retrieved 9 May 2007.
^ Elliot, J. L.; et al. (10 July 2003). "The recent expansion of Pluto's atmosphere". Nature (424): 165–168. doi:10.1038/nature01762.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Foerster, Jim. "What's The Difference Between Private Weather Companies And The National Weather Service?". Forbes.
^ Eilts, Mike (27 November 2018). "The Role of Weather—and Weather Forecasting—in Agriculture". DTN.
^ "What do the CERN experiments tell us about global warming?". Skeptical Science. 2 September 2011.
^ Brumfiel, Geoff (23 August 2011). "Cloud Formation May Be Linked to Cosmic Rays". Scientific American.

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Sarah McBroom (March 27, 2007). "Conservapedia.com -- an encyclopedic message from the right". Scripps Howard News Service.
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Lawrence Solomon (July 8, 2008). "Wikipropaganda On Global Warming". CBS News.
"Topics that spark Wikipedia 'edit wars' revealed". BBC News. July 18, 2013.
Cary Institute of Ecosystem Studies (August 15, 2015). "On Wikipedia, politically controversial science topics vulnerable to information sabotage". Science Daily.

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Neutrality

The existence of global warming is a debatable topic, and this article is saying that it is real, so it has a non-neutral point of view. Keep in mind that not everybody believes global warming is real. - ZLEA (talk) 19:02, 1 February 2017 (UTC)[reply]

The WP:TPG requires neutral section headings and says no one has exclusive claim to them, so ironically it was necessary to change it to a neutral form. Not everyone believes smoking is bad for you either. At this point, these views can still be reported on Wikipedia, but fall under the provisions of WP:FRINGE. For example, see Climate change denial. NewsAndEventsGuy (talk) 19:09, 1 February 2017 (UTC)[reply]

@ZLEA: please read the FAQ at the top of the page before asking questions already covered there. --McSly (talk) 19:17, 1 February 2017 (UTC)[reply]

The POV that global warming is not real is a fringe view that is not backed up by climate scientists at large. As McSly mentioned, see the FAQ. Dustin (talk) 22:04, 1 February 2017 (UTC)[reply]

Global warming has occurred for more than 10,000 years. The debate here is about specific man made catastrophic global warming theories. The lower troposphere satellite measurements and the tidal gauges show that no such thing has occurred. Good luck getting that into wikipedia though — Preceding unsigned comment added by 2600:100A:B127:6565:C1DF:EAD3:AD99:C354 (talk) 12:12, 14 March 2017 (UTC)[reply]

The first claim is wrong. The second claim is unsupported opinion. The third one is both a straw man and most likely based on the selective reading of unreliable blogs cherry-picking and misrepresenting data. Do you have any source to support these? --Stephan Schulz (talk) 12:20, 14 March 2017 (UTC)[reply]

As an aside, bear in mind that most veteran Wikipedia editors, as well as most people in the world, are bored with any claim that there is an "argument" surrounding global warming's existence. In all probability nobody can be bothered arguing with you any more, not because they cannot counter your claims, but because the article as it stands does that already. If you're not convinced by science, nobody can be bothered wasting their time with you.

Saying many people don't believe global warming is real isn't a reliable source of scientific inquiry. It's as nonsensical as saying, "Many people don't believe that Belgium is a real location, so you should make it clear that there is still some argument about this." A neutral point of view means sticking to factual data. Comb through the references to this article, especially the FAQ, if you're unconvinced that this topic isn't verified extensively.

As dismissive as it seems, people have better things to do than engage in constant fringe theories. This discussion page is about how to improve the article, with up-to-date data, copy editing and the likes. If you feel that a specific part of the article is not up to standard, please point it out and express your frustration. The lead section of this article is suitably sourced, so your complaint that it isn't neutral does not hold weight.Vision Insider (talk) 04:16, 27 March 2017 (UTC)[reply]

Fixing the lead

The lead to this article has gotten terribly bloated. Not only is there too much text, but the lead has three (3) illustrations of the temperature trend and two (2) illustrations of emissions. (In the body there are even more graphs of the temperature anomalies.) I'm tempted to take a meataxe to the whole thing but given this is a FA I'm slightly hesitant. Thoughts? Shock Brigade Harvester Boris (talk) 21:32, 4 February 2017 (UTC)[reply]

Get rid of all figures in the lead except the graph of temp since 1880. Isambard Kingdom (talk) 21:43, 4 February 2017 (UTC)[reply]

Would someone who knows how please look up the date it was granted FA status, and then post a DIFF to that version? There might be something to be said for just reverting to that basic text, with a few updates to AR5 etc. NewsAndEventsGuy (talk) 23:40, 4 February 2017 (UTC)[reply]

Good point. The article was approved as an FA in mid-May 2006. This is what it looked like on its first day with the coveted gold star. A tight and very readable lead with just one graph, showing the surface temperature trend since 1880. (User:Isambard Kingdom, did you cheat?) The lead in that version could be adapted to the present article with only minor changes. Shock Brigade Harvester Boris (talk) 00:21, 5 February 2017 (UTC)[reply]

No, I didn't cheat! Ha. The present lead section looks good with just one graphic. Makes the point very clearly. Isambard Kingdom (talk) 01:40, 17 March 2017 (UTC)[reply]

Do it! NewsAndEventsGuy (talk) 00:28, 5 February 2017 (UTC)[reply]

Agree, i particularly doesn't like the video and single year anomaly, i would keep a long term temperature graph and a trend map maybe with a better color table, this one looks better if it can be used: http://berkeleyearth.org/wp-content/uploads/2017/01/Trend_Map_since_19701.png Giorgiogp2 (talk) 10:25, 6 February 2017 (UTC)[reply]

I was brave enough to kill the video. I quite like the single year anomaly, or rather I like the map, because I think a pic of the geographical variation is a valuable antidote to the "global average" idea we so often get.

I propose that the emissions pix are secondary. I don't really like either, but I think one or the other should lead the "causes" section... actually I'll just do it, revert me if you don't agree William M. Connolley (talk) 21:25, 14 February 2017 (UTC)[reply]

On my screen, the "TOC" is now rather long and horrible. Does anyone know how to fold it into 2-column format? William M. Connolley (talk) 21:35, 14 February 2017 (UTC)[reply]

I'm done for now. Comments? William M. Connolley (talk) 22:07, 14 February 2017 (UTC)[reply]

feel like someone just crammed their rebreather mouthpiece between my lips....in the nick of time, too. NewsAndEventsGuy (talk) 00:46, 15 February 2017 (UTC)[reply]

Global warming in the news, again

It appears that recent political events may have pushed global warming, or more accurately, global warming denial into the news again. http://www.theguardian.com/environment/climate-consensus-97-per-cent/2017/feb/05/mail-on-sunday-launches-the-first-salvo-in-the-latest-war-against-climate-scientists

"the denial industry has lost the battle on the science. There are no reputable scientists who discount the enormous human influence on our Earth’s climate. Because they have lost that battle, they are manufacturing doubt about the science." --Nigelj (talk) 23:26, 5 February 2017 (UTC)[reply]

Shouldn't this go at the climate change denial article rather than here? Dmcq (talk) 23:49, 5 February 2017 (UTC)[reply]

Actually the world's leading expert in the trend of global temperature, John Christy, disagrees with you. As do the satellite measurements and tidal gauges — Preceding unsigned comment added by 2600:100A:B127:6565:C1DF:EAD3:AD99:C354 (talk) 12:18, 14 March 2017 (UTC)[reply]

Thanks for the laugh! . . dave souza, talk 16:37, 14 March 2017 (UTC)[reply]

Global Warming

Global warming is a term to describe the increase in global temperature which is believe to be permanently changing the earth’s climate. An issue that is not getting the immediate response it needs. Scientist believe the main cause of this warming is the continuous use of burning fossil fuels and coal. In outcomes the gases that are being produce are trapped in the atmosphere and blocking heat from escaping. Thus causing the earth to heat up and have negative results on its climate. Irregular seasonal patterns develop and increase of CO2 into the air is not controlled, which in large quantities can be a poison to the human population. If there is no stopping to burning fossil fuels and no methods of decreasing the change. Then the climate will keep responding to the increase of the warm temperature and civilizations would change dramatically.2601:280:C301:1060:4809:BE3E:60A7:56B5 (talk) 21:25, 6 March 2017 (UTC)[reply]

While I think you've got it broadly right, this page is for detailed discussion of improvements to the article, on the basis of reliable published sources. Look on the bright side, the current changes are unlikely to be permanent: they'll probably unwind in a few thousand years, and CO₂ levels are very unlikely to get to the point of being poisonous. Though they will disrupt life essentials such as food, water supply, and dry land. However, wp:not a forum dave souza, talk 22:10, 6 March 2017 (UTC)[reply]

Although CO2 may not reach human-toxicity levels outright, there's active research into the possibility of turning the oceans anoxic, which may then outgas Hydrogen sulfide, leading to mass extinction of oxygen-breathing lifeforms (like us). Surprisingly, while the article mentions species extinction, it does not really touch on mass extinction, much less this H2S theory. Maybe we should incorporate it? See for example Global Warming Led To Atmospheric Hydrogen Sulfide And Permian Extinction in ScienceDaily. NewsAndEventsGuy (talk) 23:09, 6 March 2017 (UTC)[reply]

I don't think anyone is talking about the current climate changes turning the oceans anoxic. Plus the current extinctions have more to do about pressure from the human population than climate change, though climate change will also contribute to part of it. Where did you or the original poster get these apocalyptic ideas of the end of civilization and anoxic oceans from? What's happening is quite bad enough without exaggerating it. Dmcq (talk) 23:37, 6 March 2017 (UTC)[reply]

Dmcq, I'll grant that this isn't (yet) a solid bullet point in IPCC assessment reports. Most recently they said

"It is very likely that the dissolved oxygen content of the ocean will decrease by a few percent during the 21st century. CMIP5 models suggest that this decrease in dissolved oxygen will predominantly occur in the subsurface mid-latitude oceans, caused by enhanced stratification, reduced ventilation and warming. However, there is no consensus on the future development of the volume of hypoxic and suboxic waters in the open ocean because of large uncertainties in potential biogeochemical effects and in the evolution of tropical ocean dynamics. {6.4.5, Figure 6.30}did you read the link I provided from Science Daily?" AR5, WG1, Chapter 6, pg 469

On the other hand, regulars here all know that individual papers lead the IPCC assessment reports. For background at least, is "Suffocating the Ocean" by Moises Velasquez-Manoff and published by Pacific Standard. I'm not saying the eggheads are certain about this outcome, only that some are talking about it as remote but plausible.

NewsAndEventsGuy (talk) 19:42, 7 March 2017 (UTC)[reply]

No acceleration in the rate of global warming during the industrial age has been detected

a result of the labours unfinished of Testew and Cunard

The following discussion has been closed. Please do not modify it.

The tidal gauges show no acceleration in the rate of sea level rise which was reluctantly admitted by the IPCC https://www.ipcc.ch/ipccreports/tar/wg1/409.htm The lower troposphere satellite measurements actually show a decrease in the rate warming for the last 20 years compared to the previous 20 despite human co2 production doubling http://www.nsstc.uah.edu/climate/2017/february/022017_tlt_update_bar.png The only evidence of an increase in the rate of warming come from estimates such as the GISS which has laughable methodology

I don't expect this to get in the article but there it is — Preceding unsigned comment added by 2600:100A:B127:6565:C1DF:EAD3:AD99:C354 (talk) 12:17, 14 March 2017 (UTC)[reply]

If this article is to promote the catastrophic man made global warming theories then it should mostly be about "feedback loops" because that's where the vast majority of the theorized future warming is supposed to come from. The actual greenhouse effect of co2 is very small — Preceding unsigned comment added by 2600:100A:B127:6565:C1DF:EAD3:AD99:C354 (talk) 12:23, 14 March 2017 (UTC)[reply]

I see the anti science editors have flagged my comments....but have not disputed any of it — Preceding unsigned comment added by 2600:100A:B127:6565:C1DF:EAD3:AD99:C354 (talk) 14:43, 14 March 2017 (UTC)[reply]

Meanwhile, elsewhere

In case you missed it: https://en.wikipedia.org/enwiki/w/index.php?title=Wikipedia:No_original_research/Noticeboard&diff=770351546&oldid=769648085 William M. Connolley (talk) 23:17, 14 March 2017 (UTC)[reply]

2016 1.1 deg C ref

16 of 17 in "warmest years" is more than a single pop fact over a single hot year. And 2016 seems to have varying temp reports, from the .99 on NASA CC to 1.1 here in this more recent RTE article.cite news|url=https://www.rte.ie/news/ireland/2017/0321/861284-record-global-average-temperature/ |title=2016 made history with a record global average temperature |publisher=RTE |date=March 21, 2017 |accessdate=March 22, 2017 B137 (talk) 06:32, 22 March 2017 (UTC)[reply]

This page is for discussing changes that might improve the article. Have you got a more specific suggestion thanks? Dmcq (talk) 11:17, 22 March 2017 (UTC)[reply]

Your chart

The temperature drop due to the Krakatoa eruption of 1883 is not reflected. Best guess is that the global temperature of that year dropped by about 1.5 C. That year was called "the year without a summer" as was another year in the early 1800's due to another volcanic eruption. Just making sure that when people look it up to confirm they get the right "year without a summer".

As the chart used in the article does not show a temperature drop of that magnitude, it is CRAP.

I have not checked but, if it does not show the impact of Krakatoa, it probably does not show the impact of other major volcanic eruptions since then.

My advise is that you get a better chart from competent sources.71.174.137.143 (talk) 05:31, 30 March 2017 (UTC)[reply]

Provide a source for that global average temperature fell by 1.5C. The figures in the article say that Summer average temperatures fell by up to> 1.2C in the Northern hemisphere. The eruptions of Krakatoa, Santa Maria, Agung, El Chicon and Pinatubo can all be seen in that record but the effects are more spread out in time over the world than you seem to think. Dmcq (talk) 08:28, 30 March 2017 (UTC)[reply]

If you are trying to imply that a "year without a summer" has the same average temperature as the years surrounding it, then I can only say that you need to stay away from this article as you have a bias. Besides which early temperature data has a wide plus or minus error of about 1 degree (which gets bigger the further back you go as instruments get more primitive). That CAN mean that the temperature of 100 plus years ago was on par or even higher then that of today based on instrument and recording errors. Additionally recent satellite data shows that the earth's temperature for the past 18 years has been stable to within a tenth of degree. That chart shows a spike at the end which does not exist. It is CRAP.

In short, that chart does not show the "year without a summer", it does not have error bars and it has a spike at the end that is not supported by ANY type of temperature data,

and repeating myself. The current chart is CRAP and you need to get rid of it or put in a disclaimer that it is CRAP. Find another from someone who can actually prepare a proper chart.71.174.137.143 (talk) 15:14, 30 March 2017 (UTC)[reply]

It is very obvious that Dmcq is not trying to imply that. You are applying the straw man fallacy.

Please consider that there is another hemisphere except the Northern one, and three other seasons except summer, making the Northern summer figure one of eight. Also, please consider that the Northern summer figure is probably the most extreme of the eight, otherwise another one would be used in its place. You fell for the availability heuristic and ignored that besides the figure you do know, there are other figures you do not know.

To make matters worse, you overlooked that the chart is labeled "Global Land-Ocean Temperature Index". According to 1883 eruption of Krakatoa, "average Northern Hemisphere summer temperatures fell by as much as 1.2 °C" (not 1.5). Are you sure that the scope is the same for both figures? Land and ocean?

Just provide a source for your claim of a global temperature change of 1.5°C for the whole year in land and ocean or stop bickering, OK? --Hob Gadling (talk) 15:59, 30 March 2017 (UTC)[reply]

Considering that there were no regular temperature records outside North America and Northern Europe at the time, do you want to really go and say that the rest of the world was unaffected by Krakatoa when there is minimal data either way? Europe and North America are the furthest areas of the planet from Krakatoa. Krakatoa was located in the SOUTHERN hemisphere and on the other side of the planet from both Europe and North America. It stands to reason that the closer you are to the eruption the greater the effects, at least on the short term. To even imply that the Southern hemisphere was not effected by Krakatoa, which is itself in the Southern hemisphere, is a dogshit argument. — Preceding unsigned comment added by 71.174.137.143 (talk) 16:48, 30 March 2017 (UTC)[reply]

I'd like to point out that there are probably ZERO comparable mid-Ocean temperature readings from that time. To be comparable, they need to be done on the same spot, at the same time of day and on the same date of the year. I find it difficult to believe that a ship stopped at some location in the middle of the Pacific on the 13 of May, at 7 PM on multiple years to take a temperature reading. (take your pick of dates and times if you don't like mine). As a matter of fact even today that type of data is hard to get and usually involves either satellite data or buoys. Unfortunately buoys need to be ANCHORED in place to take that kind of ACCURATE data, otherwise they will drift because of ocean currents, prevailing winds, and storms. Are you aware of ANY buoys of this type that have an anchor line stretching 10-15,000 feet to the bottom of the ocean, in order to keep them in place, whose job is to take temperature readings? I'm not!71.174.137.143 (talk) 18:14, 30 March 2017 (UTC)[reply]

I have long wondered: does smugness derive from idiocy? Or is it the other way around? ~ J. Johnson (JJ) (talk) 21:52, 30 March 2017 (UTC)[reply]

I think it's a feedback loop leading to shrill meaningless noise. --Hob Gadling (talk) 22:45, 30 March 2017 (UTC)[reply]

"do you want to really go and say that the rest of the world was unaffected by Krakatoa" You just don't get it. You are misrepresenting what I said, and I will not read beyond your first sentence. Go away. EOD. --Hob Gadling (talk) 22:45, 30 March 2017 (UTC)[reply]

I notice nobody has addressed the point that the chart does NOT show that drop in temperature in the "year without a summer" (whether that drop is 1.2 or 1.5 degrees). Since it miserably fails to show the temperature drop which has been admitted to above, it is CRAP.

I also notice that nobody has addressed the fact that temperature measurements 100 years ago had an error range of about 1 degree, which make all the squigles in the first half of the chart pretty much CRAP, making the chart itself CRAP.

Additionally I continue to notice that nobody had addressed the spike at the very end of the chart, when satellite data shows pretty much no change in the earths temperature for the past 18 years. Satellite date shows that for the past 18 years the earths temperature has stayed the same to within a tenth of a degree, again making the chart CRAP. Sorry! THERE IS NO SPIKE! IT IS CRAP!

Instead I get an argument about Krakatoa negligible effects in the Southern hemisphere, when Krakatoa itself is in the Southern hemisphere and by all odds had a greater effect on the Southern hemisphere then on the Northern one.71.174.137.143 (talk) 02:35, 31 March 2017 (UTC)[reply]

this sentence in the intro

Many of the observed changes since the 1950s are unprecedented over tens to thousands of years.[6]

The last ice age ended about 10,000 BC so the statement that the observed changes over the past "tens" of thousands of years are unprecedented is garbage, or does anyone think that going from an ice age to a non-ice age period is NOT comparable to the piddling little change since 1950.

The LITTLE ice age that bottomed in the 1300's caused widespread famine across Europe and probably the world. Recent research shows that 1/3 of villages in northern Europe vanished, because everyone either starved to death or moved south. That also seems MORE of a change then the changes since 1950.

Lastly one of the many MINI ice ages bottomed in the late 1800's so of course there will be a warming period afterwards, and even with the CRAP chart you are using, there is not much difference between 1880 and 1950 and 1950 and today. If the current theory on Global Warming caused by CO2 emissions is true then there should be a much higher change since 1950. What we have here is a theory FAIL.

As a matter of fact, there are predictions that after hitting a top we may now be heading for another bottom to a mini ice age. This is based on sunspot activity as an indicator of solar activity now showing decreased solar energy, resulting in less sunlight and a cooler Earth.

If there is a temperature cycle then there is a bottom and a top. The following is what it looks like at a LITTLE Ice Age bottom, while today we may be at a top.

https://www.eh-resources.org/little-ice-age/

The Baltic Sea froze over, as did most of the rivers in Europe. Winters were bitterly cold and prolonged, reducing the growing season by several weeks. These conditions led to widespread crop failure, famine, and in some regions population decline.71.174.137.143 (talk) 06:03, 30 March 2017 (UTC)[reply]

The sentence is from the summary of the ~1000 page report, If you want to talk about that sentence, you'll need to refer to the details in the detailed report. If you want to continue with the bowel movement claim, you'll need to provide citations to what Wikipedia calls a WP:Reliable source. NewsAndEventsGuy (talk) 08:44, 30 March 2017 (UTC)[reply]

Agree about the citations. But they pointed out a real problem with the start of the article, people shouldn't be dismissed so quickly. Perhaps it should be rewritten so it is not misread so easily. It says 'tens to thousands of years' not 'tens of thousands of years'. Up to ten thousand years ago is 'thousands of years'. I think I'll go and change it to just say 'thousands of years'.

Yes there were some predictions about fifty years ago based on cycles that we might be headed to another ice age, but the science has firmed up quite a bit since, see History of climate change science and you'll see the how the basic science has been around since 1896. The changes are not piddling. Compared to the average temperature over the last two thousand years recent yearly global temperatures are further away from the mean than the worst of the little ice age was. People in air conditioned houses may not notice but high temperatures can kill as well and it is predicted to go up a lot more. Dmcq (talk) 09:14, 30 March 2017 (UTC)[reply]

The language from the citation does not even match the "tens of thousands of years" quoted in the article. Your own source does not match that line. It is therefore CRAP. Read the actual language which is part of the citation. Whoever put that language in the article needs to go back to school in order to learn to read.71.174.137.143 (talk) 15:25, 30 March 2017 (UTC)[reply]

High temperatures can kill has got to be one of the stupidest comments I have ever heard. By that quote people going to Florida for the winter go there to die. Same for those retirees who retire to Mexico because they can get a maid on a Social Security income.

Recent temperatures are likely LOWER or at least no different then those of 1000 years ago and 2000 years ago. Both periods saw commercial wine making in England. In modern times that has recently started up again. That activity was not possible in England during the LITTLE Ice age period of about 1300-1700's as grapes do not do well in the cold.71.174.137.143 (talk) 15:36, 30 March 2017 (UTC)[reply]

If you were able and willing to read what people write, you would be smarter. Try it.

For your benefit, I will repeat Dmcq's key sentence for you:

"It says 'tens to thousands of years' not 'tens of thousands of years'."

Now read the rest. Slowly and carefully. After that, would you please stop Dunning-Krugering? --Hob Gadling (talk) 16:07, 30 March 2017 (UTC)[reply]

OK! I misread it! but that still does not change the fact that the temperature of the earth 1,000 years ago was most likely warmer then it is today. 1000 years ago the Vikings were calling Greenland "GREEN" land, and Newfoundland VINland after the grape vine. Greenland in not GREEN today and grapes don't do well in Newfoundland. The sentence is still hyperbole and not backed by any evidence. What evidence exists shows that it is in error.71.174.137.143 (talk) 16:54, 30 March 2017 (UTC)[reply]

Well, there we are: complete and utter refutation of a century of science. Who can argue with that? Who would have thought it was so simple? Why should a few little errors matter? Never mind that a real estate developer or two were involved. I'm sure those simple-minded Vikings had not invented "fluff" back then. ~ J. Johnson (JJ) (talk) 22:01, 30 March 2017 (UTC)[reply]

The intended meaning of that sentence in the IPCC report is tens TO thousands of years not tens of thousands of years, reflecting the situation that for some of observed changes being talked about, useful records only extend a few decades before the 1950s, for others it is a few centuries before the 1950s, and for a few it is a few millennia. We (disclosure: I was an author of the report) avoided writing that most of the observed changes since the 1950s were unprecedented over the last several thousands of years because for most of the observed changes we don't have useful records that long. Some rewording is needed. TimOsborn (talk) 23:58, 30 March 2017 (UTC)[reply]

The cited source is IPCC AR5 WG1 SPM which reads "decades to millenia"; I'm just fine with our text "tens to thousands of years" but it might read better if it said "some of the observed changes are unprecedented over thousands of years". We may want to cite the section of the full report that says so. I have not attempted to dig that up. NewsAndEventsGuy (talk) 01:07, 31 March 2017 (UTC)[reply]

At most it is about 1,000 i.e. the warm period in the middle of the last 2 Little Ice ages, one marking the end of the Roman Empire and a huge but unknown drop in Europe's population, while the later one is marked by a 30-40% drop in the population of the Northern hemisphere, largely made up of the Mongol Empire (that includes China, as China was a Mongol conquest) and Europe. It is now warm enough that you can grow grapes commercially in England now, it was the same 1,000 years ago and it was the same 2,000 years ago.71.174.137.143 (talk) 02:50, 31 March 2017 (UTC)[reply]

How about a section on the "BENEFICIAL EFFECTS of GLOBAL WARMING"

a short list can include the fact that increasing carbon dioxide in the atmosphere is beneficial to plants and food production. One account I came across states that at current levels of CO2 many plants are literally starving since they evolved in the distant past when the earth had more CO2 in the atmosphere. Many of the worlds worst famines and population drops were during the bottoms of the LITTLE and MINI Ice ages.

Lets not forget that famines cause mass population migrations in search of food resulting in wars. Hell! The largest empire in History was created by the Mongols who decided to move south in the 1300'and 1400's during the bottom of latest LITTLE ice age. The Roman Empire collapsed during the one before that as NORTHERN tribes moved south to escape the cold and find food. The bottom of that little ice age was around 500 AD. It's even possible that the Persian Invasions of Greece was due to search for arable land due to another Little Ice age bottoming out at that time. There is no historical evidence either way, but numbers match as Little Ice ages happen every 700-1,000 years based on the grand total of TWO that we have any kind of reliable records for.

Here's some numbers

http://www2.sunysuffolk.edu/mandias/lia/little_ice_age.html

Lamb (1966) points out that the growing season changed by 15 to 20 percent between the warmest and coldest times of the millenium. That is enough to affect almost any type of food production, especially crops highly adapted to use the full-season warm climatic periods. During the coldest times of the LIA, England's growing season was shortened by one to two months compared to present day values. The availability of varieties of seed today that can withstand extreme cold or warmth, wetness or dryness, was not available in the past. Therefore, climate changes had a much greater impact on agricultural output in the past.

The effect of the LIA on Swiss farms was also severe. Due to the cooler climate, snow covered the ground deep into spring. A parasite, known as Fusarium nivale, which thrives under snow cover, devastated crops. Additionally, due to the increased number of days of snow cover, the stocks of hay for the animals ran out so livestock were fed on straw and pine branches. Many cows had to be slaughtered.

In Norway, many farms located at higher latitudes were abandoned for better land in the valleys. By 1387, production and tax yields were between 12 percent and 70 percent of what they had been around 1300. In the 1460's it was being recognized that this change was permanent. As late as the year 1665, the total Norwegian grain harvest is reported to have been only 67 - 70 percent of what it had been about the year 1300 (Lamb, 1995.)

Is short

If there is significant global warming due to human activity, we should THANK GOD, because if there isn't then a shorted growing season during the next LITTLE ice age will see the earths food production drop resulting in massive famines and wars. If anyone is in favor of a few billion deaths please let me know.71.174.137.143 (talk) 17:30, 30 March 2017 (UTC)[reply]

What an impressive pile of cow flop. It would indeed be a short list, possibly of a negative length. These notions of "beneficial to plants", shorter shipping routes through the arctic, less snow in the winter, have all been pushed by the fossil fuel industry, but are quite illusory. Arguing that the colder temperatures during the Little Ice Age means warmer temperatures now are therefore better is ridiculous. Higher tempeatures tend to increase desrtification, but more importantly: changes in precipation patterns upset established ecologies, and tend to lead to flooding and erosion. Any increase of productivity in the higher Norwegian and Swiss valleys will hardly compensate for the loss of some of the world's best arable land on various river deltas. I could go on, but most of the folks here know this. And I forgot, you are just a blathering idiot. Most likely you didn't notice: Wikipedia is not a blog. ~ J. Johnson (JJ) (talk) 21:45, 30 March 2017 (UTC)[reply]

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