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

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube 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


The Climate Show Episode 10: David Suzuki and the sun

Posted on 3 April 2011 by John Cook

The Climate Show have released Episode 10 featuring the long awaited interview with David Suzuki. Glenn decided to take it up a notch, recording the episode at high definition. Unfortunately things went a little pear shaped when his system was unable to handle the larger video file. So this week's podcast is audio only. However, you can still watch video of the David Suzuki interview.

The loss of video was a little unfortunate as my debunk was heavily dependent on graphics. So as you listen to the audio (subscribe to the podcast via iTunes or listen directly here), perhaps the best approach would be to follow along with the following graphics. We debunked the argument "global warming is caused by the sun", beginning with a prominent example from the documentary The Great Global Warming Swindle. The filmmakers use the following graph as evidence that the sun must be causing global warming:

However, the sharp eyed reader should have already spotted the trick employed in this graph - two tricks, in fact. Firstly, they cut off the solar data in the mid-1970s, attempting to hide the decline in solar activity. Secondly, they cut off the temperature data in the early 1980s, in an attempt to hide the incline in global temperatures. When you use all the available data, the divergence between sun and temperature is clear:

There are other ways solar activity can affect climate, such as cosmic rays. As with Total Solar Irradiance shown above, there is a good correlation between cosmic radiation and climate in the past but this correlation breaks down in recent decades:

Next, we looked at several patterns you would expect to see if the sun was causing global warming. One distinctive pattern expected if the sun was driving global warming would be a warming stratosphere (the upper atmosphere). Greenhouse warming, on the other hand, predicts cooling in the upper atmosphere in contrast to solar warming:

What we observe matches the expected pattern from greenhouse warming (I used the following graph from the Scientific Guide to Global Warming Skepticism):

Another expectation from solar warming is that days should warm faster than nights, in contrast to greenhouse warming which should cause nights to warm faster than days. Observations of the daily cycle match greenhouse warming.

Similarly, solar warming should lead to summers warming faster than winters - greenhouse warming should give the opposite. Again, observations match greenhouse warming.

So multiple lines of evidence rule out the sun as the cause of global warming and point to an increased greenhouse effect as the primary driver of recent global warming.

0 0

Printable Version  |  Link to this page


Comments 1 to 4:

  1. Typo in paragraph for figure "Variation in Number of Warm Days/Nights". It reads "from solar warming is that days should warm faster than days" is should read "from solar warming is that days should warm faster than nights".
    0 0
    Response: Whoops, fixed, thanks!
  2. What is the scientific explanation as to why the divergence happens after the 70s and not early in the 20th century?
    0 0
  3. I know I've made the point previously, but the graphs showing warm nights / warm days, and winter/summer warming, suffer greatly from the use of a modern reference period. If you zero both graphs back at the beginning of the plotted period, you get a much better feel for what the difference between the trends really is. As they stand now, a casual observer might think "what's all the fuss about, they're fairly close together in recent years". Other than that - I saw all the graphics on the hot-topic website in the show notes, except that first screen cap from the video - it tells one of the most important parts of the story, might be a good idea to get Glenn to add it there, if he hasn't already. Another good rebuttal, though, and a good show in general - sad about the loss of the video, it really does make it more enjoyable to follow along. The interview with David Suzuki was good, though!
    0 0
  4. The link is broken.
    0 0

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

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us