Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Twitter Facebook YouTube Pinterest MeWe

RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


Sun & climate: moving in opposite directions

What the science says...

Select a level... Basic Intermediate Advanced

The sun's energy has decreased since the 1980s but the Earth keeps warming faster than before.

Climate Myth...

It's the sun

"Over the past few hundred years, there has been a steady increase in the numbers of sunspots, at the time when the Earth has been getting warmer. The data suggests solar activity is influencing the global climate causing the world to get warmer." (BBC)

Over the last 35 years the sun has shown a cooling trend. However global temperatures continue to increase. If the sun's energy is decreasing while the Earth is warming, then the sun can't be the main control of the temperature.

Figure 1 shows the trend in global temperature compared to changes in the amount of solar energy that hits the Earth. The sun's energy fluctuates on a cycle that's about 11 years long. The energy changes by about 0.1% on each cycle. If the Earth's temperature was controlled mainly by the sun, then it should have cooled between 2000 and 2008. 

TSI vs. T
Figure 1: Annual global temperature change (thin light red) with 11 year moving average of temperature (thick dark red). Temperature from NASA GISS. Annual Total Solar Irradiance (thin light blue) with 11 year moving average of TSI (thick dark blue). TSI from 1880 to 1978 from Krivova et al 2007. TSI from 1979 to 2015 from the World Radiation Center (see their PMOD index page for data updates). Plots of the most recent solar irradiance can be found at the Laboratory for Atmospheric and Space Physics LISIRD site.


The solar fluctuations since 1870 have contributed a maximum of 0.1 °C to temperature changes. In recent times the biggest solar fluctuation happened around 1960. But the fastest global warming started in 1980.

Figure 2 shows how much different factors have contributed recent warming. It compares the contributions from the sun, volcanoes, El Niño and greenhouse gases. The sun adds 0.02 to 0.1 °C. Volcanoes cool the Earth by 0.1-0.2 °C. Natural variability (like El Niño) heats or cools by about 0.1-0.2 °C. Greenhouse gases have heated the climate by over 0.8 °C.

Contribution to T, AR5 FigFAQ5.1

Figure 2 Global surface temperature anomalies from 1870 to 2010, and the natural (solar, volcanic, and internal) and anthropogenic factors that influence them. (a) Global surface temperature record (1870–2010) relative to the average global surface temperature for 1961–1990 (black line). A model of global surface temperature change (a: red line) produced using the sum of the impacts on temperature of natural (b, c, d) and anthropogenic factors (e). (b) Estimated temperature response to solar forcing. (c) Estimated temperature response to volcanic eruptions. (d) Estimated temperature variability due to internal variability, here related to the El Niño-Southern Oscillation. (e) Estimated temperature response to anthropogenic forcing, consisting of a warming component from greenhouse gases, and a cooling component from most aerosols. (IPCC AR5, Chap 5)

Some people try to blame the sun for the current rise in temperatures by cherry picking the data. They only show data from periods when sun and climate data track together. They draw a false conclusion by ignoring the last few decades when the data shows the opposite result.


Basic rebuttal written by Larry M, updated by Sarah

Update July 2015:

Here is a related lecture-video from Denial101x - Making Sense of Climate Science Denial


This rebuttal was updated by Kyle Pressler in 2021 to replace broken links. The updates are a result of our call for help published in May 2021.

Last updated on 2 April 2017 by Sarah. View Archives

Printable Version  |  Offline PDF Version  |  Link to this page

Argument Feedback

Please use this form to let us know about suggested updates to this rebuttal.

Related Arguments

Further viewing

Related video from Peter Sinclair's "Climate Denial Crock of the Week" series:

Further viewing

This video created by Andy Redwood in May 2020 is an interesting and creative interpretation of this rebuttal:


Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  Next

Comments 101 to 150 out of 1270:

  1. sandy winder I said nothing about what climate IS. We are all pretty much aware of what it DOES. The best climatologist is a meteorologist with a PHD (presumed). They do quite well on both short term and long term predictions (it's mid-term where they run into trouble). But there is little understanding of what really drives climate and that is what I refer to. The GHG hypothesis came and went and came back again, the level of uncertainty is quite high. They only recently discovered how vulcanism drives ENSO. There are a lot of assumptions made by predictors and most are highly questionable which is why there is not a single climate model that works.
  2. You appear to be confusing prediction with science and weather with climate. The GHG 'hypothesis' is hardly that. It is like saying that the sun heats the earth is also only a hypothesis. It is true that the predictors can not be 100% sure of what the climate will be like in a 100 hundred years any more than they can tell what the weather will be like in 100 days. But they are just as likely to be guilty of underestimating the climate changes as overestimating them.
  3. ///The as yet unanswered question is: what causes these ice ages to start and stop? Until we can answer this question with high accuracy we know nothing about what climate is or how it works./// Wrong question because the perspective is wrong. History shows us that ice ages are the climatic dominant feature and that warm periods are the anomalies. The question is "What causes the warm periods"?
  4. Mizimi You are talking about glacations within an ice age and yes the interglacials are longer than the glacations but there are only 4 known ice ages and they comprise only about 10% of the earths known history. I am not looking at just the 4th ice age but all of earth history when I say that hotter is normal. sandy I do not disagree with what you say except that the GHG hypothesis can not be viewed as theory due to lack of testing. It has not made accurate predictions because of the overestimated sensitivity. In other words the earth is not very sensitive to CO2 as a GHG. If it was we would have looked like Venus during the Mesozoic. So the simple answer is that the IPCC has seriously overestimated the sensitivity to CO2 while doing the opposite for TSI.
  5. Glacial-Interglacial cycles
  6. QM: Point taken, however if you plot proxy temps from Cambrian to present you get a downward trend in GMT from around 21C GMT to present 13.8C. Also latest thinking on Venus proposes the lack of a magnetic field has allowed water vapour to be dissociated by UV and the lighter H atoms stripped away by solar wind effects thus eventually depriving the planet of any water and therefore no oceanic component to modulate heat tranfer.....connect to the impending reversal/decline of our magnetic field??? Regarding climate sensitivity to CO2 modulation: This seems to me to be considerably overstated. Again, paleoclimate proxies indicate far higher CO2 levels than now without any thermal runaway. During the Carboniferous period CO2 levels were around 800ppm yet the GMT was apparently only 14C. Later, in the Mesozoic, CO2 jumped to circa 1800ppm and the GMT rose to around 17.5C...hardly supporting the idea of thermal runaway or tipping.
  7. A rider....I appreciate proxy data is pretty anecdotal; but regardless of the absolute conditions pertaining at those times we DO see a trend which does not support a positive,continuous feedback causing catastrophe. The carboniferous period actually teaches us a valuable lesson about how biomass substantially impacts CO2 levels: without the CO2 locked up during that period in oil/gas/coal we wouldn't be having this debate..........
  8. Pep Interesting site. They mention CO2 as a GHG released from the ocean but did not mention CH4 that was released at the same time. Now why is that? They also fail to explain why the cycles do not have the same effect because they are ignoring other cycles that happen to overlap. Read "The Solar Jerk". Mizimi I agree that the earth has cooled and that the overall trend is one of cooling (each thermal maximum is shorter and less intense) but short term (for the earth) is slowly coming out of Ice Age 4 and temperature slope for the last 5 million years is positive (there will likely be another glacation or two but it is really unpredictable).
  9. Possibly because the interest rest with CO2, ice cores, and ocean on this NOAA site so it covered the bases. National Oceanic and Atmospheric Administration, the second GHG Search NOAA
  10. Pep Interesting presentation on how it's important. It shows how strong it is as a GHG. For many years now paleoclimatologists have felt that it was the feedback that produces increased warming, not CO2, and I agree with them. The CO2 article is misleading because they say it follows temps closely but do not mention the lag which various papers put anywhere from 200 -/+ 800 to 1000 +/- 300. Afterall, they are biofeedbacks not cause, and CH4 is way stronger as a GHG than CO2. I think that the manner in which they present these GHGs is misleading.
  11. Atmospheric lifetime has to be accounted for, hydroxyl oxidation of CH4.
  12. Pep See Mizimi comments for formula.
  13. I wouldn’t worry about cows but methane hydrates are a concern. As a side note: I can’t say CO2 doesn’t contribute to warming, more likely so. Absorbs infrared energy. I agree to disagree in other words.
  14. Pep We had been discussing CH4 and tropospheric clouds in a recent article on how they form with Mizimi. Unfortunately I don't remember where I put the link to the article but I don't think it was flying cows. I believe it may have been about methane hydrates but now I can't remember. :)
  15. Good one, so when do they arrive back home? I’ll watch this thread for the link, and thank you.
  16. Pep I found the original story (I still can't remember where I put the lik originally). Strange Clouds Spotted at the Edge of Space By Jeremy Hsu, Staff Writer, posted: 01 September 2008 08:50 am ET, 30 Comments A brief opening quote: “The noctilucent or “night-shining” clouds are at an altitude of 47 to 53 miles (76 to 85 km), where meteors and bright aurora lights are not uncommon and the atmosphere gives way to the blackness of space.” and from the body of the article: “Another likely source of water vapor is methane oxidation” It's an interesting read. :)
  17. Pep I actually do not disagree with AGW, it is a valid hypothesis. What or more specifically who I disagree with, are alarmists who twist the works of skeptics and totally neutral scientists either into a denial or falsely supporting AGW, and activists who seem to worship their word as gospel. Dr. Hansen is without any doubt an alarmist from his "or we are all toast" statement, rendering his judgement clouded in my view. And since he is the primary author at Real Climate, it in turn is alarmist, so I don't go there anymore. My issue with CO2 is purely one of sensitivity. I see other causes that are stronger than CO2 induced AGW simply because AGW is weaker than originally thought and the emphasis on CO2 in particular is distracting the science and preventing finding the actual problem. I don't know if it is a blind faith, cognitive disonnance, an agenda or something else. I was taught to question everything that did not seem logical and that had stood me well in an engineering environment (I am now retired) so I do not understand their irrational behavior. If you are interested in what I think is happening see the volcanos thread, which I feel is related to this thread via Dr. Rhodes Fairbridge's (non-peer reviewed) solar hypothesis.
  18. Pep For some reason the link I posted for you is dead. I probably made another typo so here is the text, just copy and paste:
  19. Great posts, we think alike. The real climate fear from actual science is swift change, which the world past shows how volatile it truly is. CO2 views as an industry and population agenda. Ultimately humans have a natural tendency to tackle problems viewed solvable, especially when the problem involves their back end. The "other climate” mentioned have been known for quite a while but CO2 was narrowed which is ludicrous. The world itself will never be narrow.
  20. /// QM:In other words the earth is not very sensitive to CO2 as a GHG. If it was we would have looked like Venus during the Mesozoic. So the simple answer is that the IPCC has seriously overestimated the sensitivity to CO2 while doing the opposite for TSI. /// No we would not have looked like Venus during the Mesozoic because Venus and the earth are different in many ways. For one thing Venus is nearer the sun. It has no magnetic field to protect the atmosphere and it has no plate tectonics or satellite. But carbon dioxide has the same properties on Venus as it does on earth. I would though like to see some evidence that the IPCC has overestimated sensitivity to CO2.
  21. sandy I suggest that you read Spencer's work on sensitivity. It is linked here somewhere, possibly in the "sensitivity" thread. The fact is that CO2 and all other GHGs are feedbacks to solar energy. Change the solar input and the feedback changes with it. So when you see an increase in temp from GHG it is caused by changes in solar output. The case for venus is a bit more complicated but as that isn't the subject I kept it on a simplified level, using it the same way that the alarmists have (they claim we will look like venus if we don't take action, so I used their absurd notion).
  22. PS I am glad that the absurdity was not lost on you.
  23. About overestimating in climate models after all we created them, there are errors and room for debate.
  24. Pep I cant open that site. Is there a typo maybe?
  26. On Venus: When the Galileo satellite passed by, it collected a lot of interesting data. Including the fact that at IR levels, the atmosphere appears strongly absorbing IR. This is attributed to the SO2 clouds. There is further thought that the 'greenhouse' effect on Venus is caused by high level SO2 clouds rather than lower level CO2, and that most of the solar energy absorbed is via SO2. Any water vapour present would have been dissociated by UV and 'blown away' by the solar wind due to the lack of a magnetic field, thus stripping the planat of water. Currently there is a project to carry out a detailed 2 year investigation of Venus' climate and compare its' evolution with our own.
  27. Pep Thanks, that works. Mizimi They have determined that some volcanos also eject high amounts of SO2 on earth. It was mentioned in one of the articles that I linked on the volcanos thread here.
  28. July by Beck on 180 yrs of chemical CO2 analysis...showing previous values of CO2 from 1800'2 have been "beck's 180 year analysis of CO2"....lots of info.
  29. Millions tons of SO2 in the stratosphere, Mt. Pinatubo was a great example. Now it’s overestimated or was. The scare tactic is dying.
  30. Here is the "180_years" PDF.
  31. Pep That was an interesting read, even if it was a draft copy. I found the sections on ENSO and other ocean oscillations particularly of interest. Thank you.
  32. I would take 180 years with a grain of salt. :) welcome
  33. Pep Actually I have not read it yet and I don't know if its the same as what Mizimi read but I will take a look at both links later.
  34. The site contains the full extract; the other is an abstract of the pertinent findings. One possible way to check 'accuracy' is to check out the annual coal tonnages around the 1850-1960 periods as oil did not supplant coal until after this period. I rather suspect (!!)a surprise, especially since coal-burning appliances were notoriously inefficient in those times. Equally much wood was burnt during this period? rather a lot I think, and in very inefficient ways.
  35. Mizimi In rural America, coal and wood still warm many homes, albeit the systems have become somewhat more sophisticated than they were when I was growing up. I would like to use a windmill here but they are quite expensive. I'm waiting for the prices to come down.
  36. R. Keeling has posted a rebuttal and Beck has posted a reply so the debate has begun.
  37. A theory must do two things it must explain what has been observed and it must be useful to predict the result of future experiments. A theory that fails in either way is discarded. In both cases the AGW by CO2 hypothesis has some big trouble. Please don't try to make it a theory. We need it to be much better, but I don't know if it needs to be discarded.
  38. WA I agree. BTW Have you had a chance to view any of the articles that I linked to on the volcanos thread? Every time I look for newer articles I run across another one on climate sensitivity to something or another. Spencer says it lower to CO2, Kay says it higher for TSI and the last article I posted a link to in volcanos says it's plate tectonics.
  39. sorry, my s key must be sticking in the up position.
  40. Pep I just finished reading the short version Beck draft. What did you find objectionable? Mizimi What web site are they posting this argument on?
  41. Yeah I've been looking. I think we may be running headlong in the wrong direction. The satellite data that was supposed to prove a positive feedback from CO2 causing increased water vapor in fact show the opposite. I don't say we are certain but it is starting to look like there is no way CO2 can be a large climate driver. Coupled with the paleo record clearly saying it isn't...
  42. The evolution of C4 plants happened around the Miocene/Pliocene interface when CO2 levels were lower than today and C4 plants began to develop.. C3 plants cannot cope with low CO2, they require 180 -220ppm for successful growth. Experiments indicate a 58% reduction in photosynthesis if the level is dropped from 380ppm to 150ppm and up to 90% reduction below 150ppm. C4 plants require a lower ppm value as they are 'more efficient': the first C4's were grasses. Before the appearance of grasses, most plants used phosphoglyceric acid (3 carbon atoms)to photosynthesise. Hence the name C3. Grasses, on the other hand, use oxaloacetic acid ( 4 carbon atoms) for photosynthesis, and are called C4 plants. As C4 plants were more efficient they began to dominate the planet creating vast eares of savannah and effectively locking up CO2. Thure Cerling has demonstrated that C4 plants "fixed" large volumes of CO2 from the atmosphere during photosynthesis and subsequently into the soil upon death. It is considered that this lowered the level of CO2 and thus GMT, resulting in the extinction of many of the large mammals. Keelings response to Becks paper: Beck reply:
  43. Mizimi Thanks
  44. Mizimi and Pep After reading both comments and the rebuttal I tend to agree somewhat with Beck, but also fail to see the relavence to sensitivity.
  45. Mizimi I am not familiar with C3 and C4 (except for the plastique kind) but from what you said I take it that pines are C3 and maples, elms and oarks are C4. What about the leafy evergreens like cedars, C3 or C4?
  46. QM: Plants are classed biochemically as C3, C4 and CAM. C3 plants are the earliest evolved class and include all trees, bushes, shrubs with high wood/lignin & tannin content. They are the source of coal. C4 plants evolved relatively recently (8mya) and essentially are the grasses..oats, wheat, barley,bamboo alfalfa and so on. They can be woody (bamboo) but use a 4-carbon molecule in photosynthesis, hence the name. CAM's are specialists...they have means to cope with stress...high Temp, low water or CO2 etc...and include cacti, succulents and so on. Because C4 plants are more efficient chemically than the others, they return LESS CO2 to the atmosphere during respiration (about 25% less than an equivalent C3)so eventually lock up CO2.
  47. Mizimi Ok, I thought you meant trees as I had read somewhere that some are better than others as carbon sinks. I also had read that grasses were better carbon sinks than trees but not why. Interesting, thank you.
  48. QM: I did mean trees as well as other plant types. Plants ( and trees) using C3 process are the oldest species; C4 plants are newcomers. So trees ( of all types ) are C3's. C3's can tolerate much higher levels of CO2 than C4's as in early epochs, but they cannot work with low levels of CO2 (under 220ppm for example). C4's can work with very low levels of CO2 because they concentrate the gas in tissue before using it. BUT they don't like very high CO2 levels according to recent research...though this is contended by others.
  49. Mizimi Thank you, I was not aware of that.
  50. Pep John's thread on Solar Cycles is also relavent to this thread. Naturally when I used this in the Arctic Sea Ice Melt thread I was attacked by alarmists who apparently did not read it.

Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  Next

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

Link to this page

The Consensus Project Website


(free to republish)

© Copyright 2022 John Cook
Home | Links | Translations | About Us | Privacy | Contact Us