Who wants to see the future, anyway?

Blast from the past

In my December column, I wrote about the James Webb Space Telescope and the joy and excitement that comes with powerful technology. Since then, NASA has released many amazing images that have captured our collective imagination.

The telescope speaks to the human desire to experience “the unknown” by bringing it into focus. Imagine if a tool could do the same thing in climate science.

Astronomers measure distance in terms of light years, literally the distance that light travels in a year. Using light years to measure  distance explicitly links distance to time. That is, when we look farther and farther away, we are looking farther back in time. When we look farther back in time, we get headlines like “Webb telescope spots super old, massive galaxies that shouldn’t exist.”

Climate science does not enjoy the benefit of a telescope that can look back in time. To “view” the past, scientists rely on observations using thermometers, tree rings, gases trapped in kilometers-deep ice cores, and many others. To complement and interpret these observations, scientists use models that represent the physics that describe Earth’s climate.

Bringing the past into focus

A drawing of a "differential thermometer."

Some thermometer measurements date back to the 1600s. (Image iStock.)

Today, the observations of Earth are vast in number. Satellites deliver billions of daily observations about temperature; we rely on many other tools and variables to offer insight and understanding about the climate. This incredible observing capacity began in 1979.

Looking back, we have high confidence in knowing the average temperature all the way to 1850 because we covered the Earth’s surface in thermometers. We even have a few thermometer measurements dating back to the 1600s.  However, prior to 1850, we increasingly rely on proxy measurements such as tree rings and ice cores.

The certainty with which we can characterize Earth’s climate is, here and now, very high. The farther back we look, the less certain we are. As with telescopes, we can look at close objects, like the Moon with far more detail than galaxies millions of light years away. We can say that the longer back in time we look at the climate, the less focused our view.

Grounded in the present

The rich set of observations we have now help us ground models in reality.

When we use the models to look at past observations, they are tools to analyze and synthesize information to assist in understanding the observations and evaluating and calibrating the models. The accuracy and precision — the ability to “focus” the model — are high with the modern suite of observations. As we look farther back in time, we move from high degrees of certainty to a set of plausible explanations to describe the more scant and uncertain observations.

All science is challenged when attempting to predict the future. It does not yet exist and can’t be observed. Our ability to bring details into meaningful focus becomes difficult. Intuitively and factually, a weather forecast of seven days is more accurate than a seasonal forecast of nine months. At 100 years, even though the details of individual weather events are unknowable, the attributes of the collective of simulated weather events provide guidance about the state of the planet. With models serving the role of our telescope into the future, near-term events are in focus, and long-term events are not.

David Letterman prepares to throw a watermelon off the NBC tower back in the day.

Latenight TV host David Letterman used to entertain viewers by throwing random items off a highrise, including a watermelon, to observe what happens. (Image: giphy.com.)

Major differences between a far-looking telescope and a long-term climate model lie in the physical processes that are required to describe the observations. Climate science relies on laws of energy conservation (and momentum and mass) that are applied to phenomena on Earth. These laws are established to describe processes ranging from flying an airplane to throwing a watermelon off a highrise.

The Webb telescope is designed to interrogate problems for which the physical processes are both less well-known and evaluated. We are not looking at earthly processes with the Webb. In fact, we are looking for places where such forces as intuitive as gravity, for example, do not behave as they do on Earth. We look in realms where even the definition of time becomes alien to us. We look to challenge our physical understanding — with first glimpses. Uncertain physics and scant observations are expected to lead to headlines like “The James Webb Space Telescope discovers enormous distant galaxies that should not exist.”

No relief in sight

The rich sets of observations, and the simple, well-tested physical representations available to describe our climate give us high confidence about many aspects of our planet’s future. Earth is warming, sea levels are rising, and ice sheets are melting. We also can conclude with confidence that the warming is due to fossil fuels, which means we know how to limit and reverse the warming. Though we know that the weather will change, the details of how the weather will change remain unfocused and uncertain.

The fact that we have observations of this unfolding story both enforces our knowledge and improves our models. When we align the observations, simulations, and improvement of our representations of simple, known physics, we arrive at a physical climate model that is a telescope into the future. That telescope’s focus is always improving. And though the focus will tell us many new things, it is unlikely that we will find, as the Webb Telescope might, any violations of our physical understanding that will tell us that a future of planetary warming will not occur.
(Lead image: The James Webb Space Telescope at Europe’s Spaceport in French Guiana in 2021, prior to being encapsulated inside this 17 meter-high, 5.4-meter diameter fairing, which provides protection from the thermal, acoustic, and aerodynamic stresses during the ascent to space. (Image credit: ESA/CNES/Arianespace.)


  1. David Kochalko - ‘75, ‘78, ‘82

    Blithely reciting the trinity of rising temperatures, rising seas, and melting ice while asserting high confidence attributing the causal factors to fossil fuels is journalistic if not also academic malpractice. Where are the courageous voices at my alma matter who are willing and able to challenge the popular “faith” to explore deeply and with data what is known, unknown and those unknown unknowns? The claim of certainty in the face of these together with an understanding of the gapping limitations of our modeling accuracy are to say the least disappointing.


  2. Jonathan Blanton - 1975

    It is patently false and misleading to state that that we know with “scientific” confidence that climate change and global warming are primarily due to the use of fossil fuels. Scientific evidence and good judgment have been replaced by political and economic propaganda. Where have the true scientists gone?


  3. Norbert Roobaert - 1963

    Ditto to the above comments. We have no proof only conjecture by the politicians and those making money From the brainwashing.


  4. Richard Rood

    Thank you for the comments.

    Saying that I am blithe, guilty of academic malpractice, propaganda etc., provides me with an excellent opportunity for my students to examine some of the issues that we discuss in this collection on rhetoric and argumentation …


    With regard to the science of attribution of climate change, for those who might be interested here are a couple of background articles. (I believe open source.)



    Here is the chapter from the IPCC report that assessed recent attribution studies.


    I will be glad to discuss any deficiencies that you find in these approaches.

    Discussing courage is for a different forum.


    • Norbert Roobaert - 1963

      I have looked at the article that’s trying to model man’s contribution to global warming. I think that looks interesting and keeps people employed. For me much more important and meaningful questions that should be answered are what caused the English Channel to be formed in about 6500 BC? And what caused the Wisconsin glacier to melt and formed the Great Lakes about 11,000 years ago? Please give me the answers. What is happening today is minor compared to these events. Climate has been changing since the beginning of time. Man is not involved.


      • Richard Rood


        I believe that there is one thing that we can agree on. Climate change prior to ~ 10,000 years ago did not have significant involvement of humans. That does not mean that global warming, today, is not due to humans.

        In the past the climate has varied, and it has varied for physical reasons. It has not varied mystically or on a whim. Most times, when there are large variations, including the ice age cycles, greenhouse gases are involved. For example, the oceans give up a store of CO2. Presently, humans are acting on a planet scale and adding CO2 to the atmosphere. Rather than CO2 coming from the ocean, it is coming from the crust, and humans are doing that.

        I think it important that past climate has varied and we can investigate that from a physics (chemistry, biology) perspectives. It helps us to quantify the human effects.

        As for explaining the set events that you pose as a precondition for statements about what is happening today is, to me, an irrelevant appeal. Why this set? What will be the next set? I could, perhaps, provide a set of items I would like explained before preceding.

        For the benefit of anyone else who might read this, your original message and comment both make reference that climate scientists maintain this huge global conceit for financial benefit and employment. It has always seemed to me, that if the goal was enrichment, it made more sense to document that the Earth was warming and we had no reason why. Then we could ask for funds to investigate the dire mystery.

        BTW, I know that many climate statisticians can find more lucrative ways to make a living, for example, mining big data to more effectively target the sale of small appliances or developing financial derivatives. It’s not like it is the only thing we can find to do.


  5. William White - 2006, PhD NERS

    Prof. Rood,

    You missed some references in your list of climate change literature above, most notably to my mind:


    This is a great website for looking at various bits of information and to learn more about various aspects of climate change and possible contributing factors. This website includes a helpful list of references and other sites where you can find more information as you are interested and have time.

    Given the present state of climate change hysteria in your field, and the subsequent verbal and written attacks often leveled against any climate skeptics, I think the assertions that you are “blithe, guilty of academic malpractice, propaganda etc.” are perhaps more understandable, if not entirely charitable.

    I guess I would urge you to acknowledge that extraordinary claims should be supported by extraordinary proof – and that many (if not most) of the climate change assertions that I see in your articles (and others) claim a far greater certainty than what is provided by the measurements presented.


    • Richard Rood

      I suppose I can say that I missed hundreds of thousands of references from my list.

      With regards to extraordinary claims, and extraordinary proof, I think that if you set out to evaluate the literature on attribution, then you would find that an extraordinary level of proof has been realized. The three references that I provided in the ‘comments’ are a very good starting point.

      As for extraordinary claims, I don’t think that a claim that if we add heat to the surface of the Earth that it will have consequences, is especially extraordinary.

      As for the Wattsupwiththat web site, I consider it a relevant reference re climate communication, logical fallacies, and misinformation. To Watt’s credit, some of the issues pointed out about surface observations’ quality control led to improvement of the surface observations. Those improvements have helped to increase the confidence that the Earth is warming.

      You might enjoy the berkeleyearth.org website and especially its history.


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