Posted by: ericgrimsrud | August 28, 2015

 Zero carbon emissions by 2050 with no economic downsides

A new paper by Jacobson et al. of Stanford University demonstrates how all of the energy needed to support our present standard of living in the USA could be provided by alternate, non-carbon-based sources of energy even without assistance by nuclear reactors by the year 2050, only 35 years ahead.  Note that this includes ALL ENERGY needed for heat, electricity, and transport – thereby bringing CO2 emissions to near zero. In addition, the financial benefits of following this course would outweigh those associated with our continued use of fossil fuels for energy production.  The entire paper can be seen at

The paper begins with the following statement of its broader context:

“This paper presents a consistent set of roadmaps for converting the energy infrastructures of each of the 50 United States to 100% wind, water, and sunlight (WWS) for all purposes (electricity, transportation, heating/cooling, and industry) by 2050. Such conversions are obtained by first projecting conventional power demand to 2050 in each sector then electrifying the sector, assuming the use of some electrolytic hydrogen in transportation and industry and applying modest end-use energy efficiency improvements. Such state conversions may reduce conventional 2050 U.S.-averaged power demand by B39%, with most reductions due to the efficiency of electricity over combustion and the rest due to modest end-use energy efficiency improvements. The conversions are found to be technically and economically feasible with little downside. They nearly eliminate energy-related U.S. air pollution and climate-relevant emissions and their resulting health and environmental costs while creating jobs, stabilizing energy prices, and minimizing land requirements. These benefits have not previously been quantified for the 50 states. Their elucidation may reduce the social and political barriers to implementing clean-energy policies for replacing conventional combustible and nuclear fuels. Several such policies are proposed herein for each energy sector.”

And the paper ends with this summary:

“Based on the scientific results presented, current barriers to implementing the roadmaps are neither technical nor economic. As such, they must be social and political. Such barriers are due partly to the fact that most people are unaware of what changes are possible and how they will benefit from them and partly to the fact that many with a financial interest in the current energy industry resist change. However, because the benefits of converting (reduced global warming and air pollution; new jobs and stable energy prices) far exceed the costs, converting has little downside. This study elucidates the net benefits and quantifies what is possible thus should reduce social and political barriers to implementing the roadmaps.”

Looks as though the only question is – will human beings prove to be smart enough to take a course of action that will be beneficial in all regards – financially, environmentally, and morally – or will they blindly continue their fatal addiction to the 6th element in the Periodic Table?

Posted by: ericgrimsrud | August 26, 2015

Helping Obama get to the Promised Land

President Obama’s views and actions on the issue of climate change so far have been similar to those that were taken by our two leading civil rights Presidents, Abraham Lincoln and Lyndon Johnson.

With the benefit of hindsight, we now know that Lincoln’s sympathies were on the side of the abolitionists who wanted the institution of slavery to be terminated as soon as possible throughout the entire USA.  But we also now know that Lincoln believed he would be more successful in accomplishing that goal if he initially embraced a compromise position – allowing slavery to continue in the deep South but not allowing it to extend to the new western states. Thus, Lincoln initially offered both sides something they wanted while his own views then changed to his preference in response to the horrific events brought on by the American Civil War.  Lincoln was an extraordinarily savvy politician who managed to keep the Union together and to abolish the institution of slavery in just four years – an almost unbelievable feat at that time.

Lyndon Johnson was also an extraordinarily savvy politician who managed to bring the freedom Lincoln had won for the slaves of America to a higher level of ensured equal rights. Johnson had previously been a classic “Dixiecrat”, a southern Democrat in favor of racial segregation. Therefore he had good rapport with many politicians of the southern states whose support he needed to pass long overdue civil rights legislation. By gaining substantial support from southern Republicans and by clever procedural maneuvers, he was finally able to get the Civil Rights Act of 1964 passed.

Another strategy that both Lincoln and Johnson used was to encourage the Abolitionists and the Freedom Marchers of their respective eras to push for their agenda as forcefully as possible. Johnson even advised Martin Luther King to lob strident personal insults at his President – because it would “make his job easier”, Johnson said.

So what makes me think that Obama is following the paths of Lincoln and Johnson in dealing with the present issue of climate change? One is that the sheer magnitude of the climate change problem is so daunting – even more so than those of slavery and civil rights. And while the problem of global warming cannot be solved overnight, major steps forward can be facilitated by ongoing alarming events related to climate change, just as they were during the Civil War and Civil Rights eras. Another reason for thinking that Obama is following in Lincoln and Johnson’s footsteps is that he surely knows the detailed history of the antislavery and civil rights movements like the back of his hand – including the shrewd political maneuverings that finally led to successes.

So, like Lincoln and Johnson, Obama sits in the middle of a conundrum – knowing what final outcome he prefers, but also very well aware of the exceedingly difficult barriers to getting there.  Thus, he regularly provides some “good news” to both sides of the issue so that neither side runs away from the negotiation table.  In his speeches, he very clearly demonstrates that he has no doubt at all about the reality of man-caused global warming and our urgent need of strong action.  And at the same time, he allows environmentally questionable gas and oil explorations to proceed. His recent announcement concerning cuts to coal-powered power plants have probably won him some friends in the environmental corner but did not constitute a major setback for the fossil fuel companies because coal-fired power plants were already being phased out in the USA due to our surpluses of cleaner and higher energy content natural gas. On the issue of the Keystone XL pipeline, Obama seems to be aware of the folly associated with the development of this very dirty and low energy form of fossil fuel, but his actions so far have left the fossil fuel industries thinking that his administration might ultimately allow its construction.

Thus, just as Lincoln was hounded by the abolitionists and Johnson by civil rights advocates, we should continue to hound President Obama for not doing enough to end our use of fossil fuels. Tinkering with cutbacks, grants, offsets, and carbon credits might help a bit but will not be nearly enough to solve to problem. Only the abolition of fossil fuel use will do the job.  If and when President Obama manages to get a stiff carbon tax in place – either in his remaining 18 months in office or from some other post-presidency involvement – only then will he have achieved his equivalent of  Lincoln’s 13th Amendment or Johnson’s Civil Rights Act of 1964.  If he is successful in that endeavor, Obama will be remembered as a skillful politician of the Lincoln and Johnson ilk who somehow did the right thing concerning a seemingly impossible task. Our job is to continue to hound and drive him towards that goal.

Posted by: ericgrimsrud | August 11, 2015

The Hansen paper viewed as a pie plate with ice cubes

In a recent post, I drew attention to the latest publication by James Hansen et al. (see it at ) which is sure to have a huge impact on our understanding of the most imminent effects of climate change resulting from greenhouse gas warming.  I believe that the issue addressed in this paper is so important to everyone – not just professional scientists – that I will try to provide here some additional assistance is understanding its contents via a simple analogy.

Ordinarily, we assume that increased  levels of warming will result in increased temperatures, right?  Isn’t that, after all, what “warming” is all about?  But not so, actually.  As more heat is deposited into the Earth by our out-of-control greenhouse effect, there is another means by which that excess heat is dissipated that does not result in increased temperatures. That mechanism is simply the melting of ice – by which huge amounts of energy is absorbed with no change in temperature.  And with the use of simple analogies associated with the melting of ice in a pie plate, we can better understand both the Hansen paper referred to above and why this means of heat dissipation is so very important to us – of more immediate importance, perhaps, than the temperature increases we usually focus on.

What the Hansen paper is all about can be better understood by doing the following “thought experiments” (which can also be done literally in one’s kitchen, if one wishes).  Imagine a simple pie plate about one foot in diameter with edges of about one inch in height.  Then add a bunch of standard (one inch) ice cubes to it and just enough water to cover the very bottom of the plate to a depth of only about 1/8 inch. Then place a thermometer in the middle of this ice-water mixture and a towel under the plate thereby providing a bit of heat insulation from the counter top.

Now position a standard clip-on lamp directly over the center of this ice-water mixture and begin recording the temperature indicated by the thermometer as the ice slowly and steadily melts and the depth of the water level increases.  What one will observe for the next many minutes as the ice melts is that the temperature of the water does not change at all.  Until almost all of the ice is gone, the water temperature will remain at the freezing point of water, which is +32 degrees F.  Only after that point when the ice is nearly gone, will the temperature then begin to increase beyond 32 degrees.  According to the laws of thermodynamics, this result is entirely expected – no surprises, so far.

Now let’s change the above experiment somewhat so that it more closely mimics our planet –  by placing two or three ice cubes only at the very top and the very bottom edges of the pie plate – thereby creating north and south “poles”.  (For those actually doing this experiment, two strings taped to the top and bottom of the plate will prevent these ice cubes from sliding away from their polar positions).  Again we also add enough water to fill the plate to a depth of about 1/8 inch.  With a thermometer again placed in the water at the center of the plate, we again suspend the lamp over the center of the pie plate and again start recording the temperature.  Now, if we do not stir the water at all, we will observe an increase in temperature with time, as would be expected, right? Since there is no stirring, the water in the center of the pan is now going to increase in temperature immediately upon application of extra heat from the lamp.  If one moves the thermometer to the water-ice mixture existing at the top or bottom of the plate, the temperature at those two locations would be 32 degrees F as in the first experiment, right?  Since the center of the plate is now farther from the poles, its temperature is less affected by the ice at the poles.

Next, let’s additionally improve our rough simulation of the Earth by introducing some stirring of the water, lightly at first and then progressively stronger. After all, we know that our oceans consist of numerous strong currents by which heat is being continuously transferred between all of its regions. As the degree of stirring is increased in our experiment, the temperature observed at the middle of the plate will then decrease, right?  If the degree of stirring is made sufficiently vigorous, the temperature at the center can be made to decrease downwards most of the way to that measured at the “poles”.

Lastly, repeat the experiment above using different levels of constant stirring and note the time required for the length of the ice cubes at the poles to decrease in size to approximately one-half their original size under each condition of stirring. One will certainly find that this measured “half-life” of the ice cubes deceases with increased stirring, right? This happens because increased stirring brings the total heat within the plate to its polar regions more rapidly, thereby causing the cubes to melt more quickly.

So that’s it.  Very simple experiments with results that are in line with common sense, right?  But  what do these simple experiments tell us about what the Earth is likely to do in response to our extra greenhouse gas heating?  It tells us several very important things, as related below.

First, there are, indeed, two different mechanisms by which the extra heat provided by greenhouse gases is dissipated.  One is via temperature increase and the other is via the melting of ice. In addition, these experiments show us that the loss of ice can occur with either no or little change in temperature (as in the first experiment and in a later one with ice “poles” and vigorous stirring).

Secondly, these experiments tell us that the rate of ice loss at the poles of our over- heated world will depend on the degree of “stirring” or heat transfer provided by our oceans.  That is, the speed and efficiency of heat exchange between our mid latitude oceans and our polar glaciers will be determined by ocean currents and ocean-glacial interfaces – factors that we are just beginning to understand as related in the Hansen paper.

Thirdly, one of the most detrimental and immediate consequences of global warming is expected to be an increases in our sea levels and the simple experiments related above suggest that large increases in sea levels can occur with relatively little changes in the Earth’s average temperatures. This is especially true  if the “stirring” or heat transfer between the poles and the lower latitudes via our oceans is relatively efficient.  Just how efficient that transfer of heat is constitutes an extremely important question about which too little has been known up to the present.

In any case, the simple thought experiments described here allow one to better understand the purpose and goal of the paper by Hansen et al.  Its goal is to understand and determine the speed by which the extra heat of our planet is transferred to the polar regions, where most of the world’s ice is.  And what they discovered is that the rate of heat transfer will be increasing much more rapidly during the coming decades than was previously expected. As a result, their prediction is that sea levels will rise by about 10 feet by the year 2100 if our “business-as-usual” rate of fossil-fuel consumption continues – instead of less than 3 feet as was previously thought.  In order to prevent that outcome, Hansen et al. conclude that atmospheric CO2 levels would have to be reduced from its present level of 400 ppm back down to about 350 ppm. Given that our background CO2 levels are currently increasing at a rate of about 3 ppm per year and that atmospheric CO2 is removed very, very slowly by natural processes, a return to 350 ppm constitutes is an exceedingly formidable task that is doable only if extreme measures are immediately undertaken .

The main reason we have not previously been aware of these exceedingly dire predictions is that we  have not sufficiently understood the details of the “mixing” processes illustrated by the simple experiments provided above – as they play out on our planet. The Hansen paper is therefore particularly important because it attempts to understand  those processes and, in doing so, finds that these heat transfer factors are, indeed, determining ones  with respect to the changes in our sea levels that are expected to occur during the current century.  And  in case you missed the point previously, an increase in the sea level of 10 meters by the end of this century would render many of our coastal cities, including New York, London and Shanghai, uninhabitable!

Finally, thanks to Heart Climate Scientists for the following relevant cartoon.

2015 Toon 32

And Hansen et al .predict that the rate of glacial melting and fresh water production will be increasing exponentially with business-as-usual practices throughout the current century!  Yes, there does appear to be some very good reasons for becoming VERY ALARMED and for undertaking extreme and immediate actions, does there not?  The only question is are human beings going to be up to this task or will they simply continue to enjoy the fossil-fuel-fired party while it lasts?  That is the BIG QUESTION of our era – and, unfortunately, is still one that is masked by so many other issues of far less immediate importance.

Posted by: ericgrimsrud | July 28, 2015

Will it be Hillary or Bernie on climate change?

A couple days ago Hillary Clinton came out with her statement on Climate Change (see it at:  I had expected her to say pretty much what she did say and was thereby disappointed. We have already seen too much of “all of the above” approaches to the energy question.  While she is clearly in favor of our continued development of alternate means of energy production, she did not say enough about our need to discourage future use of fossil fuels.  Most significantly, she did not even mention our need for a tax on future carbon emissions.

Hillary is a shrewd and experienced politician, of course, and I am sure she knows that if she does not win the specific election in question, her long term agenda will not get to first base.  Therefore, I could envision that if and when she is in office, she might gradually take a much firmer stance against fossil fuel use.  I don’t know that, of course, and am only guessing here about her real plans. Without that guess, however, I would not vote for her at the present time.

This is because we now have another candidate, Bernie Sanders, who is “all the way there” with respect to what I believe has to be done – as soon as possible – that is, instantly upon election – if we are to have any hope in the battle against global warming.  Bernie is forcefully behind the only factor that will really make a difference.  That is an increasingly stiff tax on the combustion of all fossil fuels (see his stance at:   We cannot continue to use our atmosphere as a free-of-charge dump for the disposal of carbon dioxide.  It already has way too much of this greenhouse gas in it and the extra we add to it every day will remain there for several centuries.  Only a stiff charge for the continued disposal of that waste will enable us to develop the carbon-free energy and financial systems we absolutely must have within the next decade.

So my question to myself is:  who should I vote for – the seemingly powerful candidate that would very probably win and whose outlook might possibly get all the way to a carbon free economy later – or the one who is clearly already all the way there but might not have the political clout to defeat his Republican opponent in the 2016 Presidential election?  It’s a good thing that I still have more than a year to watch and decide.  If Bernie’s level of public support continues to increase – that would pull me in his direction.  If Hillary shows me that she “get’s it” concerning the real problem before us – that would also affect my vote.

I should add here that if Vice President Joe Biden decides to throw his hat in the ring, I would also consider voting for him. I have the highest respect for Biden and the service he has provided to our country throughout his long career.  In addition, if he were to run, I am sure that his views on climate change and how to address it would be just as forceful as those of Bernie Sanders.

Concerning other potential candidates who might have a clue concerning the looming problem of climate change – the GOP has made things far too simple for me.  It still appears than any candidate that makes it through their “vetting” process will have to be either an actual or a pretend scientific retard who will have to show his or her disdain for our nation’s scientific organizations. They will have to be in sync with the “I am not a scientist” and “its all a big hoax” national leadership of their party.

This last point made above is, perhaps, the saddest part of the dilemma in which we now find ourselves.  How the United States of America in the 21st  Century came to have one of its only two major political parties reduced to such a state of utter anti-intellectualism would be enough to make many of its founders, certainly including Washington, Adams, Jefferson, and Franklin, to be ashamed of what they have produced.  How is it possible that over those more than two centuries, the understanding of our natural surroundings by approximately half of our political representatives has actually “advanced” backwards? God help us if any of those scientific Neanderthals of the GOP is elected in 2016!

Posted by: ericgrimsrud | July 23, 2015

James Hansen speaks again

Anyone who has followed the science of climate change is by now well aware of Dr. James Hansen and the central role he has played in climate science over the last three decades.  Therefore, his most recent paper coauthored by 16 others, to appear very soon in Atmospheric Physics and Chemistry (an-open-to-public peer-reviewed journal), will be drawing a great deal of attention – as it should.

Dr. Hansen has suspected that the sensitivity of our climate to changes in our greenhouse gases has been significantly underestimated in climate models, to date, and this most recent paper supports that notion.  New insight into the magnitude of climate change is provided in this paper by its inclusion of ice sheet dynamics – a factor not previously understood well enough to be included in models.  A key and possibly controversial point made in this paper is that the amount of fresh water being produced from the melting of glaciers in Greenland and Antarctica will increase exponentially – rather than linearly – with time if our planet continues on its current course of warming.

As a result of this additional insight, the authors argue that our goal for limiting future global temperature increase should be changed from +2.0 C to +1.5 C because an increase of 2.0 C will prove to be far too distressful to our present civilization. Specifically, the authors predict that an increase of 2.0 C will cause sea levels to rise about 10 feet by the year 2100 instead of 3 feet, as was previously predicted by the IPCC. A sea level rise of 10 feet would obviously cause horrific damage, making numerous coastal cities, including New York, London, and Shanghai, uninhabitable.

So who is this guy, again, who brings us this most distasteful news at a point in time when we are not even on track for limiting future warming to 2.0 C?   Ever since James Hansen first sounded the global warming alarm in his historic testimony to the US Congress back in 1988, he has consistently been ahead of the scientific curve. His predictions have generally been both more dire and more accurate than those of the IPCC.  This new paper also offers some “good news”, however.  That is. it explains what we can do to avoid temperatures in excess of 1.5 C. Perhaps the moment has finally come when Congress will do more than ignore his advice. We will soon see. Time for needed action appears to be running out.

For a preview of the paper in question, see   Keep an eye out for its impact in the next week or so.  Also note that this paper has not yet gone through the normal scientific review process which will very likely take several weeks and result in at least some modifications of the initial version.

(note added on 7/27/2015).  Dr. Hansen has now provided an op ed in which he describes his recent paper in a condensed and lay-public friendly manner while also providing a link to the full paper.  I highly recommend that you have a look at:

Posted by: ericgrimsrud | July 17, 2015

Are our plants about to turn on us?

First, consider the following facts.  Over the Industrial Age, mankind caused the emission of about 580 billion tons of carbon into the atmosphere. This has changed the level of atmospheric CO2 from 280 ppm to 400 ppm.  If all of that extra carbon emitted by mankind had stayed in the atmosphere, the level of CO2 today would have been 550 ppm rather than 400 ppm.  Thus, we know that only 40% of the extra carbon emitted stayed in the atmosphere and about 60% went elsewhere – about 30% to the surface layers of the oceans and about 30% to plants.

So yes, what the Deniers like to say “CO2 is plant food” is true at the moment – even though the atmosphere does not like the 40% it gets (because of the global warming it causes) and the oceans do not like the 30% they get (because of the increase in acidity it causes).  And now even that simple statement about “plant food” is being questioned as it pertains to the future – because plant scientists are finding that plants are becoming stressed by changes associated with climate change.

Increased levels of carbon dioxide have caused plants to grow faster, but in the process other nutrients, such as nitrogen and phosphorous, that are required for further growth have become limiting factors.  In addition water levels and climate conditions have worsened in many regions.  All of this appears to be reducing the ability of plants to soak up that 30%  portion of mankind’s extra emissions.  In addition, as the ocean surfaces warm and become more acidic, the oceans are also expected to take up a continuously smaller portion of the excess carbon.

Therefore, an increasing fraction of our total carbon emissions in the future are expected to stay in the atmosphere because plants and the oceans are expected to take up less of it.  In addition, as global warming continues we can expect to see some vegetation that used to be sinks for carbon turn into actual sources of carbon.  One example of this is the organic matter presently stored in the permafrost of the Arctic.  As those regions of the world get warmer, that organic matter will be broken down by microbes and converted to gaseous CO2.  Also an increase in the death of trees in some of our most massive rain forests is being noted and as they decay CO2 is emitted.

Since none of these factors have been included, to date, in the IPCC’s estimates of future CO2 levels, our “allowed” future emissions of carbon – if we are not to exceed a temperature increase of 2.0 C – will have to be significantly lowered  relative to previous estimates.  Thus, when we hear today that we have just 35 years left at current emissions rates before we cross the dangerous climate change threshold, we should reduce that time limit by 5 to 10 years.  All of this is because nature will be quietly boosting her own carbon emissions over the coming decades and an increasingly larger fraction of all emissions, both natural and man-caused, that will be staying in the atmosphere.

Sorry, but that appears to be the way the mop will be flopping. Those hoping for an easy way out of the corner we have painted ourselves into will continue to be disappointed.  Gosh, it would be nice to be able to be a Denier – if only I weren’t cursed with a knowledge of the science involved!

For more details and references to these sobering additional insights, see:

Posted by: ericgrimsrud | July 11, 2015

On the raising of (Judas) Goats in Montana

Whenever  I observe an elected politician doing the bidding of well-healed corporations at the expense of the general public, I begin to suspect that there might not be any good reason for their actions other than the fact that their future livelihood might depend on the generosity of their corporate friends.  Such behavior can be entirely legal if carefully done, and due to the recent Citizens United ruling of our Supreme Court, is now even more likely than ever to occur.  It should not be surprising, therefore, to see that a few such Judas Goats among our elected officials get properly trained – that is, to lead their herds to slaughter for their own personal gains.  I am therefore wondering if Montana’s new Congressman, Ryan Zinke, is about to provide us with an excellent example of this phenomenon.

As reported in a short news release in the Daily Inter Lake of Kalispell, Montana, of July 10, the Obama administration is presently trying to correct what it believes are inappropriate sales of Montana coal deposits – by which the coal companies involved are attempting to avoid paying the State of Montana the full value of those deposits. In defense of their actions, the coal companies point out that the laws they are abiding by have been on the books since 1980. What this article failed to point out, however, is how the Citizens United ruling – which allows unlimited campaign donations – has changed everything – in favor of the well-healed. .

Ironically, one of those most strongly resisting a change in those now outdated 1980 laws is Montana’s own congressional representative, Republican Ryan Zinke, whose recent election to the House just happens to have been strongly assisted by one of fossil fuel corporations involved in the contested sales.  The question now before us, of course, is whose interests is Congressman Zinke serving in this case?  Is it those of the public or those of the corporations?  Surely, the public would prefer to receive the full value of their assets, would they not?  And other than his own self interests, I don’t see any valid reasons for Zinke’s actions in this case.  If there are any, I would be glad to hear what they are and post them on the comments section of this post.  Of course, this offer is also extended to you, Representative Zinke, should you like to send me that list.

For a more complete account of the details of these coal sales, see Thom Hartmann’s recent article at

In it, he provides the financial details of the sale and offers a creative, if also humorous, solution.  That is, since large corporations now have the right to donate unlimited amounts to the election of public officials, we now also need an analogous investment mechanism by which individual citizens can also get a “piece of that action” via their smaller investments in creative financial products such as a “Zinke Fund”, for example, that looks for new ways to give away public assets to private interests.  As Hartmann points out in the Zinke example, the “returns” for such “investments” in our “public servants” can be extraordinarily high.

Toon of the Week, thanks to Union of Concerned Scientists

2015 Toon 28

Posted by: ericgrimsrud | July 10, 2015

The BS concerning oil independence continues

We hear lot from our country’s fossil fuel corporations about the great need of our country to have our very own supplies of oil so that we are not dependent on foreign supplies.  OK, but then along come articles such as the one appearing this morning in the Washington Post  (see it at  )    that tells the larger story concerning our oil corporation’s real interests.

This article, entitled “Lifting the crude oil ban would reinvigorate the US economy” is provided by the ConocoPhillips oil corporation and is all about the EXPORT of our oil and has nothing to do with saving it in order to establish our independence.   So please do have a close look at this article and the next time you hear one of these corporations tell you about our need to become oil-independent  you should tell them, OK, but then let’s save that oil within our own country’s borders and, for that purpose, why not just leave most of it in the ground until it is needed here.

Just for emphasis in your statement to them, you might want to inject a “STUPID” in there somewhere, but I myself don’t think that word applies here.  These guys are not stupid with respect to the promotion of their product.  They just hope you are.

Posted by: ericgrimsrud | July 8, 2015

An explanation of the ice core record

In my previous post, I provided an “exam” that I had made up in an attempt to inject a bit of humor onto this blog.  In the process, however, I received some serious questions concerning one of the figures I had used.  Therefore, I am now going to use this “teachable moment” for providing an explanation of that figure, which is shown again below.  In order to digest what is about to follow, a few brain cells will have to be temporaritly dedicated to the task.  Because of the central importance of this figure, however, I can assure anyone who has some interest in the science of climate change that they will feel rewarded for their efforts. This figure really does provide the essence of what we are up against.


This figure shows the concentration of carbon dioxide thought to have been present in our background atmosphere over the last 800,000 years. All but the most recent of these measurements came from an “ice core record” provided by the EPICA Dome C research station located on a remote polar plateaus of Antarctica, about 1,300 miles from the South Pole and managed by a consortium of European countries.  The CO2 trapped in the air pockets of that very long ice core are assumed to reflect the CO2 content of the Earth’s atmosphere at the time when the snowflakes that led to that bit of ice were first formed and settled to the ground. The age of each cross section in the ice core can be determined by counting the number of visible “rings” from the top of the core.  These rings are formed by the increased transport of dust to the Antarctic continent during every summer season.

The reason for including this figure in the exam referred to above was to show the extremely sharp rise in CO2 observed during the Industrial Age at the very right edge of the graph where CO2 rises sharply from 280 ppm to 400 ppm.  Nevertheless, most of the questions I received concerned the rest of the graph in which the CO2 level is shown to have risen and fallen several times between about 180 and 280 ppm over the 800,000 year time span.  The bottoms and tops of these oscillations are known to be associated with the glacial and the interglacial periods, respectively, of the last 800,000 years with the last interglacial period in which we now live (called the Holocene) starting only about 12,000 years ago. The cause of these oscillations in and out of glacial periods is now well-known and will be explained in the remainder of this post.

A quick summary:  These oscillations between glacial and interglacial periods are caused by three factors.  One is the exact position and orientation of the Earth as it rotates around the Sun.  Another is the decrease or increase in glaciation on the Earth as it either warms or cools.  The third is the emission or absorption of carbon dioxide as the Earth either warms or cools.  For more details of each of these factors, read on.

Over the last 50 million years, the Earth has been cooling and changing from the hot “water world” it used to be with sea levels about 70 meters higher than today. Due to plate tectonics, the continents of the world have also been drifting northward. India, for example, was an island in the Southern Hemisphere (SH) 60 million years ago and drifted northward until it rammed into the continent of Eurasia in the northern hemisphere (NH).  As a result of this drift, a majority of the Earth’s total land mass today is in the NH with oceanic surfaces more prevalent in the SH. As we will see, this fact, along with the detailed way in which our planet rotates about the Sun combine to cause the glacial / interglacial oscillations shown in the first figure.  So how exactly does our planet rotate about the Sun?  That question will be addressed next.

The path of the Earth’s rotation about the Sun is defined roughly by a circle which the Earth traverses once each year.  Simultaneously, the Earth spins about its rotational axis once each day.  If that was all there was to the Earth’s orbit, however, there would have been be no glacial to interglacial transitions and the Earth would have had the same climate year after year during the last million years.  The fact is, however,  the detailed motions of the Earth relative to the Sun also include three minor twists and turns that are caused by the gravitation pull of the other planets in our solar system.   These minor perturbations cause the natural climate changes we are trying to understand here and are called the Milankovitch cycles in honor of the Serbian mathematician who correctly predicted them back in the 1920’s.

One of these minor perturbations is to the orbit taken by the Earth. Its nearly circular path actually changes continuously between circular and slightly elliptical.  The other two variations concern the rotational axis of the Earth. The angle of its tilt relative to the Sun continuously changes by a few degrees and it also wobbles (precesses) continuously. For more details concerning the Milankovitch cycles,  I will refer you to Wikipedia.  For our purposes here we only need to know that these subtle changes in our planet’s motions create continuous alterations in how our Northern and Southern Hemisphere is irradiated by the Sun.  For example, whenever these minor orbital effects cause the north pole to be pointed more directly towards the Sun, the summer season then experienced in the NH will, of course, be somewhat warmer than usual. More on the importance of the NH’s summer later.

Next, we need to think about the extent of glaciation that exists throughout the Earth at any point in time.  This has a large effect on the Earth’s temperature because incoming radiation from the Sun is effectively reflected back into space if that radiation strikes a snow or ice covered surface and tends to be absorbed if it strikes either the ground or the surfaces of the oceans.  We call the fraction of sunlight reflected  the “albedo” of the Earth.  The total albedo of the Earth in its present condition, for example, is about 0.30 indicating that 30% of incoming solar light is reflected back to outer space.  Therefore, increased glaciation of the Earth will  increases the reflection of incoming sunlight and this, of course, will cause the Earth’s temperature to decrease.

Next, note that because the NH has much more land mass than the SH, the total changes in the extent of glaciation on Earth at any point in time will depend largely on what’s happening  the NH – where between glacial and interglacial periods the southern extent of glaciation over North America, for example, changes from the position of Kansas in the USA to the Arctic coast line of northern Canada.  Similarly large changes in glaciation also occur over the continents of Europe and Asia during a glacial to interglacial transition.  The SH, by comparison, does not have such vast land masses over which large changes in glaciation can occur. None of Australia is never covered with glaciers and all of Antarctica is always covered with glaciers.  Therefore, there is relatively little change in the extent of glaciation over those two continents of the SH and neither one contributes significantly to the the Earth’s total changes in albedo as it moves between glacial and interglacial periods. Thus, it is in the NH where large changes in glaciation and changes in the reflection of incoming sunlight can occur.

If you have followed the sequence of thoughts provided so far, you will now understand why we can declare the following simple rule of thumb:  the direction of glacial / interglacial changes is determined largely by how “nice” the summers are in the NH.  If by changes in the Milankovitch cycles, the NH is being provided “good”  (that is, warmer) summers relative to the average, then the glaciers of the NH will retreat northward. On the North American continent, the southern edge of glaciation might thereby begin retreat from Kansas to Minnesota and through Canada and up to the Arctic Ocean.  These changes in glaciation would then have a large effect on the amount of solar radiation that “sticks” to the Earth versus that which just “bounces off”.  Thus, as more sunlight sticks as the glacier recedes, the Earth gets progressively warmer.  Thus, a relatively small change in the Milankovitch cycles is greatly amplified by its effect on the glaciers of the NH.  Conversely, when the Milankovitch cycles change so as to cause the NH to have cooler than average summers, the opposite events occur. The glaciers of the NH then begin grow and advance southward causing increased sunlight reflection and continuously lower temperatures..

OK, but we have not yet explained the changes in CO2 concentration observed over the last 800,000 years as shown in the first figure and the answer to this question also brings us to the third major influence on the Earth’s temperature.  When the Earth is warming as it comes out of a glacial period, the oceans begin to warm as well, of course, and as they do they release a large amount of CO2 into the atmosphere.  This release of CO2 occurs several hundred years after the initial period of warming caused by changes in the Milinkovic cycles and the Earth’s albedo.  But from that point forward, the increasing level of CO2  provides a third driving force for continued warming during the following 5,000 years required to reach the next interglacial period.

An increasing level of CO2 provides additional warming because CO2 is a Greenhouse Gas (GHG)  providing a “blanket” of thermal insulation between the surfaces of the Earth and outer space.  The GHGs manage to do this by absorbing infrared (heat) radiation emitted by the Earth and its lower atmosphere and then reemit IR radiation in all directions including back down towards the Earth’s surface. Without the GHGs the major portion of the IR omitted by the surface would simply pass into outer space thereby creating a colder world.  The amount of warming thereby caused by the continuously increasing CO2 level is then further amplified by causing increased vaporization of water, as well, which is ubiquitous throughout most of planet and is, itself, a powerful GHG.

As an addition to the above explanations, I will provide another figure showing ice core records obtained again form the Dome C site and also from the Vostok site some 600 miles away which is managed by Russia and provides the same type of information going back about 450,000 years.


This figure shows the temperature deduced from these two ice cores and in the bottom row shows the relative amount of glacial ice thought to be on the planet at all times over the last 450,000 years (deduced from separate geological measurements).

There are several points worth noting in this figure. One is that the temperatures deduced over time at the two different sites are in excellent agreement. Since these sites on the Antarctic plateau share the same background atmosphere, this  result would be expected and lends credibility to the ice core analysis technology  Another point of interest is that the variations in temperature with time closely match the variations of the CO2 level shown in the first figure – as would be expected if the causes of the glacial / interglacial oscillations provided above are valid.  And finally, extent of glaciation or “ice volume” over the entire Earth does, indeed, correlate well with the rise and fall of temperature and CO2 levels, as would be expected if the explanations for the glacial / interglacial cycles provided here is correct.

That will have to do it for now in explaining the first figure shown above and the reason why we have had both glacial and interglacial periods over the 800,000 years.  For more details and addition information, I can refer you to a more complete “short course” on the subject of climate change offered on my main web site,  Just go there and hit the short course tab.

Finishing with the BIG QUESTION: in our modern Industrial Age how can we expect to get away with increasing our atmospheric CO2 to levels so much higher than have seen in more than a million years?  The answer to that question is clearly not yet known by anyone who takes the science seriously.  We are presently doing an experiment on the only planet we have and most of our scientists who know a great deal about this think we might very likely be headed out of our present interglacial period in a direction that is opposite of that from which we came. In that case, we will be saying goodbye to mankind’s beloved Holocene and hello to a hotter and unknown period to be increasingly called the Anthropocene – whatever that place turns out to be.



Posted by: ericgrimsrud | June 27, 2015

An exam for professional aptitude

We hear a lot today about the need for increased testing in our public schools.  The reason for these additional exams is commonly claimed to be to ensure that students are learning properly and that the teachers are doing their jobs. If we do that, however, I would like to see a test of the sort provided below in which the student’s potential for fitting into our country’s various professional opportunities are also assessed.  That multiple choice exam might something like the following.

Question #1:  We commonly use numbers to indicate the relative magnitudes of some quantity of interest.  For example, would 400 of something be greater than  280 of those things.

a) yes      b) no       c) I am not a mathematician

Question #2:  We often use graphs to indicate trends in time.  If you were asked to make a plot of the world’s population from say 0 BC to the present, do you think the line produced by those annual data points would curve upward?

a) yes      b) no      c) I am not a statistician


May Temperature Anomaly

Question #3:  Take a moment to inspect the graph shown above.  It shows the average surface temperatures of the Earth for the months of May over the last 125 years.  From this graph, do you think that the surface temperatures in May have increased over the time span shown?

a) yes     b) no       c)  I am not a meteorologist



Question #4:  Take a moment to inspect the graph shown above.  It indicates the level of CO2 in the background atmosphere over the last 800,000 years.  Be sure to note the very sharp spike at the very right edge of the graph.  This spike began about 160 years ago when our CO2 level was 280 ppm and resulted in the current value of 400 ppm.  Note also the the CO2 level had never previously exceeded 290 ppm during the 800,000 year period shown.  We also know, of course, that the Industrial Age began about 160 years ago.  From these data, would you suspect that the recent surge in background CO2 levels to 400 ppm was caused by mankind’s activities during the Industrial Age?

a) yes     b) no    c)   I am not a geologist

Question #5:   Scientists know that CO2 and the other greenhouse gases in our atmosphere provide an insulating layer or blanket around the surfaces of the Earth.  If you put on a heavier coat, do you think you would get warmer?

a)  yes    b) no      c) I am not a physician

Question #6:  This exam has admittedly been heavily weighted toward scientific competency, so let’s finish with a question from the humanities.  Some think that the country of England is older than the United States of America.  Do you agree with that statement?

a) yes   b)  no   c)  I am not an historian


OK, that is the end of the test and the question now is how do we grade it.  In doing that we must now recognize that the “answer key” depends on where and how the students will fit into the needs of our society and for that reason there should be three different answer keys, as related below:

If we want to produce students that will fit into any one of the following professions – medicine, nursing, pharmacy, optometry, law, dentistry, engineering, construction, research science, insurance, veterinary science, real estate, plumber, acting, janitor, bank teller, auctioneer, hair dresser, electrician, plumber, dancing, forestry, hotel management, coaching, art, music, economics, computer technology, journalist, architecture, business owner, sales, journalism, education, military, farming, mental heath care, airline pilots, social work, ministry, librarian, and homemaking – then the students who answered (a) to each question should be steered towards any of those professions and given scores of 100%.

All is not lost, however, for the others.  For those who selected (c) for all of the questions will find that they are well suited for and indeed needed by the controlling political party of our country – the GOP.  Note, for example, that the present leaders of the House (John Boehner) and the Senate (Mitch McConnell) are both from the GOP and, when asked about their views of the global warming problem both responded with “I am not a scientist”.  Thus, those who answered (c) on all questions will feel right at home in the modern GOP and should be able to find political positions at all levels of government.

In addition, there is also a great future within the GOP for those somewhat braver soles who chose (b) for answers to all of the question.  The present Chairman of the Senate’s Committee on Environment and Public Works is none other than James “its all a big hoax” Inhofe, a prominent GOP leader from Oklahoma.  In running the environmental programs of the USA from his office, he is going to need more than “a few good men” in order to carry out his objectives.

So there you go. There will be jobs for everyone in the future. Some will find employment in the traditional professions and others in the “new age” ones being created by our present GOP leadership. In signing off, I will also admit that we will surely need our very best and brightest to fill positions in these new age professions. How, for example, are we going to reduce the levels of CO2 in our atmosphere by developing ever more sources of fossil fuels? And I am sorry that I can be of no help with that one.  I am not a magician.

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