NOAA: Time history of atmospheric CO2 (2011 update)

This is an amazing visualization of the carbon dioxide concentration in the atmosphere from today to 800 000 years ago made by  the U.S. National Oceanic and Atmospheric Administration (NOAA). The video is credited to Andy Jacobson, CIRES/NOAA.

The full video (3min 14s) shows direct measurements of CO2 in the atmosphere at more and more data points over the globe (1979-2011), then the Keeling data set from Mauna Loa (1958-1979), then finally CO2 concentrations in bubbles captured in ice cores drilled from the Antarctic ice sheets. In the first segment, note especially how the seasonal changes changes the CO2 concentrations more in of the northern hemisphere than in Antarctica (compare the red and blue dots). This is simply a brilliant visualization of a massive amount of research over more than half a century.

The HD-video (.mp4) can be downloaded here (e.g. for use in presentations):

A shorter and simplified version (59 seconds) is here:

The same short video is included in this NOAA clip, with a narrative by Dr. James Butler, NOAA:


James E. Hansen: “Earth’s energy imbalance” GISS Lunch Seminar 20110413

This is a really interesting presentation by Dr. James Hansen (NASA GISS/Columbia) of the main points from a paper, now published as:

Hansen, J., Sato, M., Kharecha, P., and von Schuckmann, K.: Earth’s energy imbalance and implications, Atmos. Chem. Phys. Discuss., 11, 27031-27105, doi:10.5194/acpd-11-27031-2011, 2011.

The paper can be downloaded for free at the journal website  here. The reviewers’ comments are also available.

The slides Hansen show in the presentation are hard to see in the video, but the figures are all in the paper referenced above.

Hansen’s presentation is not primarily aimed towards the general public, but he explains many of basic concepts and assumptions that are made in the paper, so it is not too hard to follow the presentation, especially if you also read the paper.


Richard B. Alley at AGU09: “The Biggest Control Knob”

Image from Dr. Jeff Masters’ WunderBlog.

“The Biggest Control Knob: Carbon Dioxide in Earth’s Climate History” (57:06)

Bjerknes Lecture at AGU2009. Presented by Richard B. Alley Earth and Environmental Systems Institute, Pennsylvania State University, University Park, Pennsylvania, USA

Great lecture by the master science communicator Prof. Alley.  The talk covers the very basics of paleoclimate: how do we know that CO2 is the main driver of climate.

The lecture is available for download at the AGU website, but unfortunately it is only available in flash format.

For your convenience I have made a vimeo-version available:

Richard Alley at AGU09 from Per Wikman Svahn on Vimeo.

There are a number of good posts written about the lecture, if you want to read more about it before you watch it:

Dave’s landslide blog.

Steve Easterbrook

Dr. Jeff Masters’ WunderBlog.

Hans-Joachim Schellnhuber at the Four Degrees or More Conference 2011

Prof. Hans-Joachim Schellnhuber (Potsdam Institute for Climate Impact Research, Germany) held two great lectures at the Four Degrees or More Conference, July 2011 in Melbourne, Australia.

Lecture 1: “Strange Encounters behind the 2°C Firewall: The Global Picture” (1:03)

The video starts with an introduction by the organizers of the conference and include parts of Prof. Schellnhuber’s long CV. The actual talk start at 23:00. The image looks strange in the beginning, but then you can clearly see the slides.

The talk gives a broad overview of the climate change impacts and challenges for mitigation, including some very good slides illustrating different emission pathways (se image above).

You can download the video (.mp4) or audio (.mp3) here:

The slide set can be found here: 12JULY_session-1_schellnhuber-1.1. (Note: It is not exactly the same slides as in the video/audio).

Lecture 2: “Climate Change: The Critical Decade” (1:01)

The second talk was a public lecture and is a better recording with both live video of a charming Prof. Schellnhuber and slides cut in. Nice!

The talk is not as technical and frank as the first, as it is aimed at a more general audience, but it is great science communication from a real expert.

The talk can be downloaded (.mp4 or .flv) here:

The second talk can also be found in Univ. of Melbourne’s iTunes Podcast here:

The rest of the conference videos also holds some interesting talks and can be found here:

The WBGU reports mentioned in the talks can be found here:

James Hansen, Eelco Rohling and Ken Caldeira at AGU11

Great short talks by James Hansen, Eelco Rohling and Ken Caldeira at a press conference briefing at the American Geophysical Union Fall Meeting 2011.

The powerpoint presentation is here: AGU_paleo_final (note that the order in the PPT is different from the video).

Some highlights from the video:

James Hansen argues in the talk that “The target that has been talked about in international negotiations for 2 degrees of warming is actually a prescription for long-term disaster.” (, and that previous warm periods were less than two degrees Celsius above preindustrial values  (image from Hansen & Sato (2011)).

Eelco Rohling argues that “in natural context, the ‘equilibrium’ sea level for current anthropogenic forcing is 25 ±3m higher than today” (see image above from the presentation by Rohling, it shows historical sea level corresponding to CO2 forcing) and that the previous interglacial was associated with very fast sea level rise rates, even above current sea level: “rates of rise above 0m of 1 to 2.5 m/century”.

Ken Caldeira talks about high climate sensitivity (“earth system sensitivity”): “Event 55 million years ago (PETM) suggests, with long-term feedbacks, 5.5 – 8 ⁰C ( 10 – 14 ⁰ F) per CO2-doubling” (image from the presentation).

Some of the papers that are discussed in the talks:

Hansen, J.E., and Mki. Sato, 2011: Paleoclimate implications for human-made climate change. In Climate Change: Inferences from Paleoclimate and Regional Aspects. A. Berger, F. Mesinger, and D. Šijači, Eds. Springer, in press.

Rohling EJ, Grant K, Hemleben Ch, Siddall M, Hoogakker BAA, Bolshaw M, Kucera M. High rates of sea-level  rise during the last interglacial period. Nature Geosci 2008; 1: 38-4. ngeo.2007.28

James Hansen
Director, NASA’s Goddard Institute for Space Studies, New York, New York, USA.

Eelco Rohling, 
Professor of Ocean and Climate Change, Southampton University, Southampton, United Kingdom.

Ken Caldeira
, Senior Scientist, Department of Global Ecology Carnegie Institutution of Washington, Stanford University, Stanford, California, USA.

Ben Santer at AGU11

Ben Santer’s talk “A Tribute to Stephen Schneider and an Example of ‘Setting the Scientific Record Straight'” at American Geophysical Union Fall meeting 2011 (The Stephen Schneider Global Environmental Change Lecture).

The 30 minute talk starts with a tribute to Stephen Schneider, and is followed by a debunking of Prof. Will Happer’s claim in a testimony to the US House of Representatives (see image above). The Q&A that follows includes a discussion of potential factors that might have caused the slowing down of global warming since 1998 (aerosols from Chinese coal plants, the solar cycle, natural variability etc.) and two personal anecdotes about Stephen Schneider.

CG43G : AGU Fall Meeting 2011 from American Geophysical Union on Vimeo.