Climate Science: What We Need to Know

Richard Alley is a world-renowned climate scientist and glaciologist who chaired the National Academy of Sciences Committee on Abrupt Climate Change, contributed to the Intergovernmental Panel on Climate Change (IPCC) report, and shared the 2009 Tyler Prize for his work that “advanced understanding of how human activities influence global climate, and alter oceanic, glacial, and atmospheric phenomena in ways that adversely affect planet Earth.”

Richard on the neve of the Franz Josef Glacier, NZ. Photo taken by Geoffrey Haines-Stiles as part of the NSF-funded film Project Earth - The Operators' Manual. Photo courtesy of Richard Alley.

He is the author of The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future (Princeton University Press, 2000).

Researcher: Richard Alley
: Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University
Research Location
: The ice sheets of Antarctica and Greenland

Clearly famous in scientific and academic arenas, Richard Alley is a source of reliable information for news reporters, at least in part because he has a very down-to-earth (pun intended) way of talking about the climate system. He may be better known to the general public from YouTube videos. On these segments, he has been the focus of interviews with news anchors, sung songs about the rock cycle and about scarce resources on Earth, and performed a “dance” to illustrate the climatic effects of changes in Earth’s orbit. He has also been the subject of cartoons.

For this column, I asked Richard what he thinks the public needs to know in order to understand climate change. He promptly sent a reply, which was easy to understand and used examples to illustrate his points. It is quoted below.

For key ‘to-knows,’ it is hard. In some sense, the biggest ones are actually not scientific at all.

First off is that science works. Climate scientists are scientists. Science really is not mass spectrometers and space shuttles, but a set of rules to keep us from fooling ourselves — by requiring that we test our good ideas against the real world, set aside the ideas that don’t work, and keep the ideas that work better in predicting what will happen when we do the experiment or drill the next core. The scientific techniques that produce computers and medicines and new crops also lead to our understanding of the climate and how we will change it. Climate science has made many successful predictions; there really are no big problems with it. We can surely improve it, but it already works.

The second ‘to-know’ might be that scientists are paid to do a lot of things—learn what no one else in the world knows, share that knowledge with others, and help them use that knowledge to do good things. We often call these [things] research, teaching, and service; but they are discover, share, and help. Oddly enough, part of “discovering” is arguing. To learn whether an idea is really good, we try lots of ways to prove it is wrong. If we fail, then the idea is strong. While we’re trying to prove the idea wrong, we’re arguing. So, there will always be scientific articles coming out and scientists saying things that disagree with other scientists.

While we are arguing, we scientists have a pretty good idea what is solid, what is speculative, and what is just silly, but politicians and other people don’t. So, governments have set up ways to learn from the scientists what is solid, speculative, or silly.

In the United States, Abraham Lincoln and Congress established the National Academy of Sciences to advise the government on matters scientific. Scientists are asked to volunteer their time, with the public watching, to serve on committees including the whole range of scientific views, and to summarize the science for the people.

In Lincoln’s time, the Academy looked at such questions as how to keep the new iron-sided warships (remember the Monitor and the Merrimack) from rusting and how to figure out which way was north on a foggy night when the iron plates attracted the compass. Today, the Academy still looks at practical questions, and some of these include climate.

You can always find a scientist, or a politician, to make statements on the “other” side. The wise approach is to listen to the assessment mechanisms, such as Lincoln’s Academy. And they have said, consistently since the 1970s, in many, many reports that human CO2 is turning up the Earth’s thermostat and this will cause challenges for us that can be met if we address them.

After that, the next ‘to know’ probably is that the warming effect of CO2 is physics. It is not based on some correlation between rising CO2 and temperature, but on fundamental physics of how Earth’s energy interacts with molecules in the air. It is measured by satellites, and from the ground and in the laboratory, and is observed fact. We’ve known the basic physics for over a century. After WWII, the Air Force really nailed how energy and CO2 interact. This knowledge was useful for things such as heat-seeking missiles — if you look for the heat of the enemy’s engine in the wrong wavelength, the CO2 is in the way and you can’t see the target.

From here, lots of other things matter. Yes, we are raising CO2. We know how much oil and coal we’re burning, and we see their CO2 in the air and the surface of the ocean. The climate changes so far are fairly small, but if we burn all the coal and tar sands and such, the changes will be much bigger. The changes so far have caused winners and losers. The bigger the change, the more losers and the fewer winners, so things get worse in the future.

For good scientific reasons, the uncertainties don’t help us. The changes may be a little better, or a little worse, or a lot worse, but we don’t find evidence for a lot better. (The opposite of warmth melting ice and raising sea level would be cold growing ice, and while we don’t expect that, it isn’t good or easy. We don’t want glaciers to bulldoze Columbus, Ohio!) So, the more uncertain we are as climate scientists, the more worried we should be about the future. But, there are all kinds of options. If you want to make the economy as big and wealthy as possible, you don’t ignore this, you start now to invest in dealing with it. –Richard

While many media outlets continue to present climate change science as a controversial topic, the “successful predictions” that Richard alluded to are significant. Some of the very early calculations and predictions about climate were later verified by observations. In 1896, Svante Arrhenius hypothesized that increases in atmospheric carbon dioxide would result in an enhanced “greenhouse effect,” which has occurred. In the 1920s and 1930s, Milutin Milankovitch, a Serbian mathematician, suggested that changes in Earth’s orbit would explain past glacial periods; his early calculations were later borne out when scientists found a way to obtain long-term climate records from sources such as ice cores, ocean sediments, and coral reefs.

A 2007 article in Science magazine (a peer-reviewed journal) was titled “Recent climate observations compared to projections” (Rahmstorf et al.). The authors analyzed observations of carbon dioxide concentrations, sea level, and global mean surface temperature from the 1990s to 2006 and compared them to some of the predictions (based on climate models) that had been published in the 2001 assessment report by the Intergovernmental Panel on Climate Change (IPCC). Their conclusion was that the projections in the 2001 IPCC reports were very much in line with changes that had been observed through 2006 in temperature, carbon dioxide, and sea level rise. In the case of sea level, the models actually underestimated the amount of change.

Other noteworthy climate predictions that were subsequently validated by data include: nighttime temperatures would increase more than daytime temperatures, winter temperatures would increase more than summer temperatures, and the Arctic would warm faster than the Antarctic. Also validated were the amount of cooling and the length of time the eruption of Mt. Pinatubo in 1991 would influence climate.

On April 14, 2010, Richard visited Columbus, Ohio, for the 50th anniversary of polar studies at Ohio State University. In his formal presentation titled “Bungee-Jumping on the Climate Roller-Coaster: Ice Cores and Abrupt Climate Change,” he stated as a simple fact that adding CO2 into the atmosphere will have a warming influence. In essence, he said: “It’s pure physics. There are some who want to talk about if and how much, but basic principles of atmospheric physics answer the ‘if,’ and we know a whole lot about ‘how much.’ There is no serious debate that CO2 affects climate. You can, however, debate what to do about it; and this is where the policymakers come in.”

Throughout his presentation, Richard made analogies that helped the audience understand the content. He ended with a photograph of musk oxen in their instinctive “defense circle” to protect the younger and weaker members of the herd. It was another direct analogy to help us understand the situation: We need to face this threat to our survival and each do our part to defend humankind from a clear and present danger. Doing so will require us to work together.


Rahmstorf, S., A. Cazenave, J.A. Church, J.E. Hansen, R.F. Keeling, D.E. Parker and R.C.J. Somerville. 2007. Recent climate observations compared to projections. Science 316: 709.

This article was written by Carol Landis. For more information, see the Contributors page. Email Carol at

Copyright June 2010 – The Ohio State University. This material is based upon work supported by the National Science Foundation under Grant No. 0733024. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work is licensed under an Attribution-ShareAlike 3.0 Unported Creative Commons license.


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