Wednesday, August 3, 2011

Sea Level Rise

I will be discussing this topic in various blog entries over the next several weeks, possibly longer, as I will concentrate on tropical systems affecting my area in other blogs, as warrented.

Sea level rise is one effect of anthropogenic global warming that is both complicated and simple. It is complicated by the complexity of ice sheet behavior. Some factors, such as ice sheet lubrication by meltwater penetrating to the interface between ice and rock beneath the ice sheets have only been known about for the past few years (more on this later), changes in the geoid as ice sheets melt and the mass balance of the Earth changes as a result, isostatic rebound continuing from the prior ice age, and from today's ice sheet melting. Also potential changes in weather patterns--shifts in mean high pressure centers and storm tracks, as well as in the ENSO cycle will probably be significant in augmenting or slowing sea level rise in many areas--unfortunately confident predictions of weather pattern shifts as anthropogenic global warming proceeds are not possible as yet.

Many laypeople assume that sea level rise will be uniform. After all if you add water to the ocean, it should rise everywhere, shouldn't it? Not so. The ice sheets of Greenland and Antarctica contain quadrillions of tons of mass, and have significant gravitational effects. If, for example, the Greenland Ice Sheet melted completely away tomorrow, global sea level would rise on average 23 feet. However, because gravitational attraction would be reduced near where the Greenland Ice sheet used to be, sea level would rise considerably less near Greenland, and considerably more at the antipode relative to Greenland. It could be that sea level rose 18 feet near Greenland, and 28 feet at Greenland's antipode. (Isostatic rebound of the land under the former Greenland Ice sheet would ultimately reduce this effect). Since the West Antarctic Ice sheet is near Greenland's antipode, and contains enough ice to raise sea levels by 16 feet, this gravitational effect would be mostly counterbalanced if it melted simultaneously, and most of the globe would experience sea level rises between 36 and 42 feet.

A good illustration of the non-uniformity of sea level rise is shown in the map below. It is perhaps unfortunate that sea level rise has been most marked in the western tropical Pacific while the North Atlantic and eastern Pacific which most of the developed world (North America and Europe) have seen sea level rises below the global average. A sea level rise of 10 mm (1 cm)/year on the northeast seaboard would concentrate minds! However, this map shows the ocean we have:

The simplicity of sea level rise is that it is inevitable. A warmer world is already resulting in temperate and tropical mountain glaciers melting everywhere (q.v.)

Mountain (alpine) glaciers do not have enough ice to raise sea levels by catastrophic amounts of course. However they do represent a significant fraction of the sea level rise occurring today. Another factor adding to sea level rise is thermal expansion as the oceans absorb heat trapped by rising concentrations of carbon dioxide, methane, and other greenhouse gases. Thermal expansion seems to be the primary driver of sea level rise at present. However, it is likely to be overwhelmed by massive melting in ice sheets during the late 21st and 22nd centuries. Recent work indicates that thermal expansion may not have played a large role in the Eemian interglacial 120,000 years ago compared to meltwater from ice sheets. However an extra few feet will just be another twist in the knife our descendants will have to face.

Sea level functions as a crude thermometer for the Earth. Sea level is determined by the temperature of the oceans, and the mass of the water the oceans contain. During the next three centuries, much of the more than 30 quadrillion tons of ice on our planet will melt. Even the East Antarctica Ice sheet. The amount of heat required to melt more than 30 quadrillion tons of ice is enormous. Enough to raise the atmospheric temperature to more than 1000 °F! While heat is absorbed by melting ice, global atmospheric and oceanic warming will be slowed. It will be much warmer, but temperatures will be livable in most places while the heat sink of ice melt operates. In 2250, St. Louis may have the average temperature of Phoenix or Miami, but it is perfectly possible to live in those cities (whether agriculture will be possible in the Midwest is another matter). The heat energy absorbed by melting ice and the warming of the oceans will both contribute to sea level rise, even as atmospheric temperatures do not rise by many tens or hundreds of degrees. The ocean depths, mostly between -4°C and 4°C, will also slowly absorb heat as it diffuses from above. (A warming of the ocean depths in future centuries, so that they were 30 °C all the way down would provoke an additional sea level rise of about 15 meters, as can be computed from this table but that won't happen as long as ice sheets exist to cool the ocean where they come in contact. In other words, not for many centuries.)

Is radiative forcing from our greenhouse gas emissions enough to remove all ice sheets from the surface of the earth?

Well let's see. Current radiative forcing by antropogenic greenhouse gas emissions is estimated to be 2.77 watts per square meter of the Earth in 2009. The surface area of the Earth is 510,072,000,000,000 square meters. This represents about 1,412,900,000,000,000 watts per second!

But wait! As MichaelSTL has reminded me, humankind has also increased aerosol emissions into the atmosphere, which reduce radiative forcing. He has generously provided the following two links, here and here.

So let's recalculate again. Using the figures for 2010 from this link courtesy of MichaelSTL, the net radiative forcing, adding the effect of aerosols, the figure of 2010 is 1.6628 W/m2. This revised figure gives us 850,000,000,000,000 watts per second for the whole surface of the Earth.

850 trillion watts, wow! But how much heat is that, really? After all, visiting Turkey in 1999, Mike and I were agog at the dollar being worth 650,000 Turkish lira, and spending 10 million Turkish lira for dinner!
Well it does collapse down. Going by this energy unit conversion table, a watt-hour (3600 watts) represents about .8598 of a kilocalorie, the heat required to increase the temperature of 1 kg of water 1 °C. 4187 watts raises one kg of water 1 °C. A kilogram of water is a liter, and there are 1,000 liters in a cubic meter, and a billion cubic meters in a cubic kilometer. Also, the melting of ice into water takes tremendous energy, as much as raising the temperature of water 80 °C! And ice is not necessarily at 0 °C--I'll assume that the average temperature of all the ice in ice sheets is -20 °C. The specific heat of ice is half that of water, so it takes 90 kcal to melt the typical kg of ice under that assumption.

So we have 850,000,000,000,000 watts per second to play with. Dividing by 4187 yields 203,000,000,000 kcal per second to play with. Dividing by 90 to melt a kilogram of ice yields enough energy to melt 2,255,000,000 kilograms of ice. Per second. This is 2,255,000 cubic meters of meltwater per second. Which is about 1 cubic kilometer every 7 minutes 23 1/3 seconds, or about 71,160 cubic kilometers of meltwater per year. Enough to melt all the ice on the surface of the Earth in 421 years. Of course this would mean no temperature increases in the atmosphere or oceans. All the heat would be absorbed by melting ice.

Of course we are not melting enough ice to yield 71,160 cubic kilometers of meltwater per year, even though our greenhouse gas emissions are trapping sufficient radiation to do so. The atmosphere and surface of the land is warming. The oceans are warming. The oceans are now our primary heat sink.

But the amount of anthropogenic greenhouse radiative forcing is increasing steadily. Current projections show it rising easily to 4, 5, and possibly 6 watts/square meter as the 21st century wears on. As temperatures rise, melting will accelerate on the margins of ice sheets, through the collapse of ice shelves in contact with warmer oceans, and acceleration of glacier movement provided by meltwater on the surface of glaciers and ice sheets working downwards to the ice/rock interface.

Rigorous scientific examination of the effects of anthropogenic global warming on sea level rise began surprisingly recently, with a paper by J. H. Mercer in 1978 on the possible collapse of the West Antarctic Ice Sheet. It would be very generous to say there was much scientific research into the effects of anthropogenic global warming on sea level in the 1960s and 1970s. If you had asked most qualified scientists back then, I suspect that they would have answered that increased snowfall on polar ice sheets would counteract the effects of melting alpine glaciers and thermal expansion. This 'consensus' was surprisingly long-lasting---after a few papers made a splash in the 1978-1981 period, research into the effects of AGW on sea levels, the hypothesis that AGW would result in major sea level rises fell into disfavor, or more accurately, neglect. This continued through the 1980s, and with some exceptions, through the 1990s. The discovery of outlet glacier acceleration in Greenland during the first years of the 2000s changed this. But that will be for a future blog entry.

Adding an interesting article about arctic sea ice during the Holocene Optimum.

Saturday, July 2, 2011

Global warming is here, and soon in an unprecedented way!

On June 30, NOAA released the new climate normals for the 1981-2010 period for the USA. Average temperatures were 0.5°F higher in 1981-2010 than in 1971-2000. Since the period 1981-2000 is included in both periods, this means that the 2000s were 1.5°F warmer than the 1970s in the USA! There can be no clearer indication that global warming is here!

This is a stunning rate of temperature rise. Half a degree per decade. If temperatures continue to rise at this rate, the 2090s will average 4.5°F warmer than the 2000s, and 6°F warmer than the 1970s! And the temperature rise will almost certainly not remain constant. Due to humanity's accelerating consumption of fossil fuels, carbon dioxide concentrations in the atmosphere will accelerate their rise and temperature rises will almost certainly accelerate as well. 0.5°F/decade almost certainly represents an underestimate of how much temperatures will increase during the 21st century.

Humanity has never lived in such a rapidly warming environment. Ever. Nothing comes close in our planet's history except for the Paleocene–Eocene Thermal Maximum (PETM)

The PETM was a huge warming triggered by mass releases of carbon dioxide and methane from the oceans 55.8 million years ago. Temperatures soared by more than 5°C from what was already a warmer environment than the present. The average temperature at the North Pole was 73°F, comparable to Miami. For tens of thousands of years there was not one snowflake. Not one floe of ice. No frost. Anywhere.

So how does our present addition of carbon dioxide to the atmosphere compare to what happened during the PETM? Much research has been done in the last decade, and the scope of carbon releases during the PETM, and their speed compared to our own time has become clear.

And the comparison is not good.

Here is a graph showing carbon releases into the atmosphere. Our current additions of carbon to the atmosphere are already more than 5 times greater than during the PETM, and are continuing to accelerate as the developing world industrializes, and the developed world does very little. Projections show that our carbon emissions will nearly triple, to 15 times the carbon emission rates of the PETM.

Graph of net carbon emissions into the atmosphere from Scientific American:

And a sediment core sample showing the PETM:

Dr. Lee Kump, one of the most renowned experts in the PETM, has written an article, The Last Great Global Warming for the July 2011 Scientific American. It makes sobering reading.

Some highlights from Dr. Kump's article:

Until recently, though, open questions about the event have made predictions speculative at best. New answers provide sobering clarity. They suggest the consequences of the planet’s last great global warming paled in comparison to what lies ahead, and they add new support for predictions that humanity will suffer if our course remains unaltered.

But what surprised us most was that this gas release was spread out over approximately 20,000 years—a time span between twice and 20 times as long as anyone has projected previously. That lengthy duration implies that the rate of injection during the PETM was less than two petagrams a year—a mere fraction of the rate at which the burning of fossil fuels is delivering greenhouse gases into the air today. Indeed, CO2 concentrations are rising probably 10 times faster now than they did during the PETM.

But what surprised us most was that this gas release was spread out over approximately 20,000 years—a time span between twice and 20 times as long as anyone has projected previously. That lengthy duration implies that the rate of injection during the PETM was less than two petagrams a year—a mere fraction of the rate at which the burning of fossil fuels is delivering greenhouse gases into the air today. Indeed, CO2 concentrations are rising probably 10 times faster now than they did during the PETM.

Species extinctions are on the rise, and shifting climate zones have already put surviving plants and animals on the move, often with the disease-bearing pests and other invasive species winning out in their new territories. Unlike those of the PETM, modern plants and animals now have roads, railways, dams, cities and towns blocking their migratory paths to more suitable climate. These days most large animals are already penned into tiny areas by surrounding habitat loss; their chances of moving to new latitudes to survive will in many cases be nil.

Current global warming is on a path to vastly exceed the PETM, but it may not be too late to avoid the calamity that awaits us. To do so requires immediate action by all the nations of the world to reduce the buildup of atmospheric carbon dioxide—and to ensure that the Paleocene-Eocene Thermal Maximum remains the last great global warming.

I have to disagree with Dr. Kump in the last extract from his article. Calamity does await us. The scientific community has known for almost 50 years that our fossil fuel emissions will warm the atmosphere. And yet next to nothing has been done. During the 1970s we had our best chance of limiting fossil fuel emissions during the first energy crisis. We made some cosmetic changes, but no real reforms. During the 1980s we slept through the soothing lullaby of the Reagan administration's neglect of environmental issues. During the 1990s Clinton triangulated away any meaningful environmental and energy reforms, and failed to provide any leadership on the Kyoto Protocol. The second Bush administration's hostility to environmental and energy reforms has been told in many long accounts, and requires no further comment by me.

And now we have Tea Party fanatics who would rather send the Earth straight to hell than acknowledge scientific reality, blocking any reforms to increase energy efficiency, or environmental protection. The Tea Party fanatics even want to reduce study and research about Global Warming!

We've never missed an opportunity to miss an opportunity.

I don't see how we can avoid calamity. It's not just the USA--cheap, carbon rich coal is powering the development of China--lip service is paid there to global warming, and greenwashing in China may be more prevalent than in any other country. India, South America, and even Africa are expanding their fossil fuel consumption rapidly. Coal is cheap, almost everywhere, and the worst thing we can consume. Short term thinking conquers all.

It makes me sad. I live on a beautiful barrier island, St. Simons Island with my partner. It is beautiful, a great place to grow up and a great place to live.

By 3000 CE, all of this will be gone. My house and island will be under a warm, acid sea, so deep that the sun will be only faintly visible. Rising to the surface, no land will be visible. The same will be true for land where billions of people live now, and where billions get their crops and foodstuffs from. And we're doing nothing to stop it. And with the current trajectory of carbon emissions, and our refusal to face the situation squarely, the remaking of our fair planet into an acidic, hot, steambath of a world seems inevitable.

Wednesday, June 15, 2011

New Maunder Minimum? Don't Count on it!

There's been a lot of loose talk in the past couple days about a new Maunder Minimum that will save us from the consequences of our greenhouse gas emissions. Would that were true. Even if a new Maunder Minimum does happen, the radiative forcing by additional carbon dioxide will overwhelm the effects of a reduction in solar activity, even a prolonged and deep one.

A NASA image of the Maunder Minimum:

Andrew Rivkin writes about this latest deus ex machina here.

Dr. Doug Biesecker, the head of NOAA's sunspot team, has created a slideshow presentation here.

And Dr. Biesecker has written up a report "Predicting Solar Cycle 25" which goes into further detail.

An article about the case for a second Maunder Minimum, from The Economist, a source I generally find credible, is here.

Richard Black of the BBC also has an interesting take on the possibility of a Maunder Minimum II and its effects here.

The main issue is that even if a new Maunder Minimum does occur, it will offset only a small part of the radiative forcing of the additional carbon dioxide in the atmosphere. Estimates of the reduction of solar radiation during the Maunder Minimum are on the order of 1 watt/square meter. But the radiative absorption by carbon dioxide and other greenhouse gases is already almost 2 watts/square meter, and will be around 9 watts/square meter by 2100. A Maunder Minimum II would slow global warming slightly, but not stop it.

I hope Maunder Minimum II does take place. It would be helpful. And give us some breathing room for enacting reforms in energy consumption and protecting the environment in ways to slow down global warming further.

Unfortunately, our political and business history shows that even if a new Maunder Minimum takes place, we will squander the opportunity and declare the problem solved. Humanity has never faced the global warming problem squarely in the past, and I hardly expect it will do so now. And when the sun resumed its normal radiative output, global warming will quickly become catastrophic.

Tuesday, June 14, 2011

Atmospheric Carbon Dioxide hits new record; the rise's acceleration.

Atmospheric carbon dioxide hit a new all time record at the Mauna Loa observation site, as it has in every May since observations began. 394.15 ppm, on track to hit 400 ppm in spring 2014. Recent graph below:

Carbon dioxide's rate of increase in the atmosphere has increased during every decade of record, except for the 1990s, when it was slowed by the effects of Mount Pinatubo's eruption in 1991. The 2000s show a continuing acceleration, making up for the slowdown of the 1990s. The rate of acceleration is about 0.3 ppm faster for each year per decade. It is very disturbing.

Finally, arctic sea ice is melting very rapidly. It is too early to say that it will reach a new record lowest summer minimum this September, but it is behaving as it would were it to reach a new minimum this year.

And I love Mike Luckovich's cartoons. Especially this one:

Saturday, June 11, 2011

Global warming since 1995 'now significant'

A story with powerful conclusions in updated data--global warming is REAL. And the trend since 1995 is undeniable (except by the simple-minded and dishonest).

The story, with links to relevant reports included:

Monday, May 30, 2011

The Causes of Climate Change conference--Boulder, CO 1965

Are human technology and activities forces of geophysical scope, capable of affecting the entire planet Earth? Surely not, thought most earth scientists in 1940. But a quarter century later, the consensus was beginning to shift. Several factors were involved in this shift. First of all, unprecedented economic growth. As I noted previously, during the first half of the 20th century, continuous, exponential economic growth was not a given. Two world wars and the Great Depression had interrupted economic growth in many developed countries. In 1950, industrial output was lower than 1913 in several major economic powers, such as Germany, France, and Japan. The Soviet Union and the United Kingdom were not much better. True, the USA had more than tripled its industrial production during that period.

Many scientists in the 1940s and 1950s assumed that carbon dioxide emissions would remain relatively constant. Gilbert Plass assumed that humankind's carbon dioxide emissions would be a flat 6 billion tons annually. (The IEA released a report on May 30, 2011 that humankind's carbon dioxide emissions soared past 30 billion tons for the first time in 2010, q.v.).

By 1965, humankind's carbon dioxide emissions were greater than 12 billion tons annually, and rising by more than half a billion tons per year. The assumption that carbon dioxide emissions would remain relatively low was incorrect.

Second, the work of Drs. Roger Revelle and Gilbert Plass showed that the oceans would not, could not, absorb all of humankind's carbon dioxide emissions, and that additional carbon dioxide would increase absorption of infrared radiation.

And then, Dr. Charles Keeling proved through his meticulous measurements of atmospheric carbon dioxide, and his isotopic analysis, that humankind's activities were increasing carbon dioxide in the atmosphere. During the first couple years of his measurements, it was postulated by some scientists that there could be a natural cycle that causes carbon dioxide concentrations to fluctuate, and it was possible that he was observing the uptrend of a natural cycle. And in fact there is such a natural cycle---the ENSO cycle does cause carbon dioxide concentrations to fluctuate by a few parts per million. But as carbon dioxide concentrations continued to rise each year, by 1962/1963 there was no possible doubt. Atmospheric carbon dioxide concentrations were rising, and humankind was responsible. For the past 50 years, no serious scientist has doubted that.

This graph shows the Keeling measurements for atmospheric carbon dioxide from 1958-1966. I would have preferred a 1958-1965 graph to dovetail with what the scientists at the "Causes of Climate Change" conference knew, but it is close enough for my blog, and the trend was clear:

Although the conference was organized by Dr. Revelle, the inspiration for it happened in 1963 Dr. Revelle had a conversation with astrophysicist and atmospheric physicist Dr. Walter Orr Robertsm who founded the National Center for Atmospheric Research in 1960. Dr. Roberts pointed out the aircraft contrails in the sky early one morning, and said that they would be indistinguishable from natural cirrus clouds in a few hours. They had a morning meeting, and when it broke for lunch, Dr. Revelle and Dr. Roberts went outside and could see the contrails from earlier, smearing out. By the time they finished lunch, the contrails looked just like cirrus clouds. Dr. Roberts wondered if adding cirrus clouds to the atmosphere could change the climate. Dr. Revelle wondered too.

The National Center for Atmospheric Research. The futuristic buildings served as a set for the comedy classic Sleeper, directed and written by Woody Allen.

Also in 1963, Dr. Ried Bryson (1920-2008), meteorologist and geologist, and one of the few scientific opponents to anthropogenic global warming, noticed on a flight across India to a scientific conference noticed that although the sky was cloudless, he could not see the ground, with all the smoke from brush and cooking fires. He noticed similar hazes in Brazil and sub-Saharan Africa. Dr. Bryson thought that global dimming would trigger global cooling--and that was the major threat that humankind's activities would have on the environment, a view that influenced Dr. Isaac Asimov (1920-1992) during the 1960s and 1970s.

During the last few years of his life, Dr. Bryson revised his views and concluded that global warming from the greenhouse gases humankind emits are the greater threat.

An aside on global dimming. It is a legitimate scientific viewpoint, and in fact during the 1950s and 1960s, the rise in global temperatures did pause, and increased pollution in the industrialized countries coupled with increases in tropical haze from cooking fires and brush fires and fires set to clear forest land may have had enough of an impact to blunt the rise in global temperature. Since the 1970s, increased pollution controls in the most advanced countries coupled with the relentless rise in concentrations of atmospheric carbon dioxide have clearly overwhelmed any cooling effect from aerosols in the atmosphere which promote global cooling.

To save time and effort, I am not going to go into every scientist that attended the conference, or go into everyone's theories or what they said. The main purpose of the Boulder conference, at least officially, was to discuss the mechanisms of natural climate change.

Until the 1950s, it had been believed that there were four major ice ages over the past 2 million years. And this viewpoint persisted in most of the general scientific community until the 1970s. In fact, the four ice ages are referred to in Dr. Arthur C. Clarke's novel 2001: A Space Odyssey (1968). [There are not many references to the novel, which was released in July 1968. There are many references to the film, of course.] This went with the reassuring uniformitarian mindset that typified earth science studies from the time of geologist Dr. James Hutton to the mid 20th century. Over the past 50 years, the realization that changes in the Earth's environment can be sudden and far reaching has led to a more neo-catastrophism mindset, of which the extinction of the dinosaurs by the impact of a comet/asteroid is the most prominent example.

Discoveries in the 1950s lead to the realization that ice ages and interglacials were far more frequent--more than 20 glaciations were identified by 1965, although this new knowledge took a long time to diffuse into the general scientific community. This work had been done by Drs. Harold Urey and Cesare Emiliani (q.v.) Their discoveries also indicated that climate change could have been rapid, although this discovery was resisted. However, in the early 1960s, work by Dr. Wallace Smith Broecker (Wally) (1931-) on ancient tropical corals also showed evidence that climate could change rapidly. [Dr. Broecker will be the subject of a forthcoming blog entry.] Also, Dr. Edward Lorenz (1917-2008) discussed his work on computer simulations of weather patterns, which was proving to be chaotic. Dr. Lorenz wondered whether climate states could also prove to be chaotic.

The implications were becoming clear. Climate had changed more rapidly in the past than had been believed before. Most of the scientists who attended the Boulder Conference on Climate Change were convinced of that by the time the conference was over. But it took a long time for this new consensus to diffuse into the general scientific community. To use an analogy, the discoveries of the 1950s had planted the seed of the possibility of rapid climate change. The 1965 conference was when the seed sprouted.

The work by Dr. Charles Keeling (q.v.) had shown definitively by 1965 that humankind's activities were measurably and significantly increasing the amount of atmospheric carbon dioxide. Dr. Gilbert Plass had overthrown the old belief that increases in atmospheric carbon dioxide would not increase the amount of infrared radiation trapped by the atmosphere---additional atmospheric carbon dioxide clearly would. So would humankind's carbon dioxide emissions trigger a sudden change in the Earth's climate? That question left the attendees of the Boulder conference uneasy.

The minutes of the conference published in 1966 contain this interesting statement: "We are just now beginning to realize that the atmosphere is not a dump of unlimited capacity but we do not yet know what the atmosphere's capacity is"*

*National Academy of Sciences, Committee on Atmospheric Sciences Panel on Weather and Climate Modification, Weather and Climate Modification: Problems and Prospects. 2 vols. (Washington, D.C., National Academy of Sciences, 1966), col. 1, p. 10.

Wednesday, May 25, 2011

Charles David Keeling

Dr. Charles David Keeling (1928-2005) was the giant of the 20th century in atmospheric carbon dioxide studies. It was his single-mindedness that established continuous carbon dioxide monitoring. Without him, it might have been decades more before continuous carbon dioxide monitoring was established.

Dr. Charles Keeling was born in Scranton, PA on April 20, 1928. A precocious child, he obtained his B.S. in chemistry from the University of Illinois in 1948 at age 20, and earned his PhD in chemistry from Northwestern University in 1954.

Dr. Keeling had many interests---he was an accomplished piano player and loved hiking and camping in the mountains of California, when he moved he moved after obtaining his doctorate. He was a postdoctorate fellow in geochemistry at the California Institute of Technology from 1954-1956, where he developed new instruments which for the first time could measure carbon dioxide in the atmosphere in parts per billion. His instruments were later supplanted by the electron capture dectector invented by Dr. James Lovelock in 1957, which was adopted worldwide for sampling in the 1960s.
In 1956 he was invited to join the Scripps Institution of Oceanography by Dr. Roger Revelle (q.v.)

Dr. Revelle said about Dr. Keeling "He's a peculiar guy. He wants to measure CO2 in his belly...and he wants to measure it with the greatest precision and the greatest accuracy he possibly can.". Keeling had taken his instruments to sites in the Sierra mountains, but there were problems. When the wind shifted so that the sites were downwind of major cities like San Francisco and Sacramento, the concentrations rose sharply. What Dr. Keeling needed was a pristine site, thousands of miles away from large cities and industrial concentrations.

The 1950s and 1960s were a golden age for scientific research. The impetus of the Cold War, and unprecedented prosperity and rising wealth stimulated large and increasing research budgets. The International Geophysical Year of 1957-1958 (IGY) further augmented research budgets. Climate change, much less anthropogenic global warming, was not a big priority with the IGY, but Dr. Revelle made funds available for Dr. Keeling to make his carbon dioxide observations at the Mauna Loa Observatory, beginning March 1, 1958. Dr. Keeling also supervised a carbon dioxide sampling program from the new Antarctic bases established during the IGY.
Mauna Loa was an ideal site for Dr. Keeling's measurements. It was far from any population concentration, and the site being over 11,000' in elevation placed it above the inversion in the atmosphere that separates the low level moist trade winds from the middle levels of the atmosphere, reducing anthropogenic influences even further.

Continuous carbon dioxide monitoring was a new idea. Before discussing it with Dr. Keeling, Dr. Revelle had envisioned sampling carbon dioxide at various pristine sites around the world during the IGY, and then a new sample program comparing the IGY readings to observations made during a subsequent sampling program ~ 20 years later, say in 1980. And the Antarctic observations were dropped in the year or two after the IGY. Scientific research budgets were large and rising, but not unlimited, and atmospheric carbon dioxide measurements were not the highest priority. And as we shall see, there were serious threats to cut off the Mauna Loa measurements in the 1960s, before the importance of the measurements was fully appreciated by the scientific community.

Dr. Keelings measurements soon showed that carbon dioxide was accumulating in the atmosphere. Dr. Revelle had been proven correct--the buffer mechanism he had proposed that prevented the oceans from absorbing all the CO2 humankind was emitting was making a measurable difference in atmospheric concentrations!

Dr. Keeling published his preliminary findings in the June 1960 of Tellus in the article "The Concentration and isotopic abundances of carbon dioxide in the atmosphere" This article contains the graph I embedded below:

Two years wasn't much though. After all, there could be some sort of atmospheric cycle going on. Today we know that is ridiculous, and we can safely dismiss the denier cranks who make that argument, but 50 years ago it was still a reasonable position. Dr. Revelle continued funding Dr. Keeling's carbon dioxide measurement program, but outside events intervened. A stock market 'crash' in the spring of 1962 wiped out more than a quarter of stocks' value---the market soon recovered, but there was a disruption to the Scripps Institution's endowment. Also in the early 1960s there was a sort of pause in the growth of budgets for scientific research, and increasing amounts were being absorbed by NASA. There were waves of growth in scientific research funding in the late 1950s and the mid 1960s, but the early 1960s saw something of a pause. And most important of all, no research agency considered Dr. Keeling's carbon dioxide measurements truly compelling---the measurements were interesting, yes, but not enough for an agency or institution to fund themselves. And the Mauna Loa Observatory was relatively isolated---an advantage in obtaining pristine atmospheric carbon dioxide measurements---but a disadvantage in that it was expensive to supply and operate.

Dr. Revelle was able to divert some funding to keep Dr. Keeling's measurement program going through 1963, and by late in that year had some promising indications of permanent funding from the National Science Foundation. (NSF) But in January 1964 the money ran out. Carbon dioxide measurements at Mauna Loa Observatory stopped.

This triggered a reaction in the scientific community--Dr Keeling's carbon dioxide series was suddenly appreciated much more in its absence!--and the NSF quickly approved permanent funding. After a 3 month hiatus in February, March, and April 1964, the Mauna Loa measurement program was resumed on May 1, 1964, and has continued to the present day.

As I said before, some scientists looked at the first 2 years of data from the Antarctic stations and Mauna Loa with legitimately skeptical eyes. The ENSO cycle was not well known 50 years ago (which does affect carbon dioxide concentrations in the atmosphere, particularly in the Pacific), but a cycle was plausible. However, as the measurement program went on, and carbon dioxide continued to increase its concentration in the atmosphere every year, such skepticism, never widely held, fell by the wayside. Since the mid 1960s, no reputable meteorologist, climate scientist, or physicist has denied that humankind's emissions are driving the atmospheric carbon dioxide increase. By the mid 1960s, the increase was undeniable. The following graph shows how carbon dioxide concentrations were increasing through the mid 1960s.

Note the funding hiatus in 1964. Mind the gap!

The importance of Dr. Keeling's measurements of atmospheric carbon dioxide cannot be overstated. Dr. Revelle showed that the oceans would not absorb all the carbon dioxide humankind emitted. Dr. Plass proved that increases in the concentration of carbon dioxide in the atmosphere would increase infrared radiation absorption. And Dr. Keeling proved that carbon dioxide concentrations were increasing, in a measurable and significant amount. As these facts disseminated through the scientific community, the scientific consensus swung decisively to the reality of anthropogenic global warming by the mid 1960s, and has remained so.

An aside here---it is frequently asserted by deniers that meteorologists and climate scientists believed in global cooling in the 1970s. This is utterly false. An analysis of peer-reviewed articles on future climate change from the period 1965-1979 shows that predictions of anthropogenic global warming outnumber predictions of anthropogenic global cooling by more than 6 to 1 (specifically 44 to 7).

Whenever a denier claims that the scientific community was predicting global cooling in the 1970s, that denier is either ignorant, or deliberately lying.

Dr. Keeling was concerned enough about rising carbon dioxide levels to participate in a panel by the Conservation Foundation on March 12, 1963 "Implications of Rising Carbon Dioxide Content of the Atmosphere", the report issued being among the first to speculate that anthropogenic global warming could be dangerous to the Earth's biological and environmental systems. It includes on page 6: "many life forms would be annihilated" [in the tropics] if emissions continued unchecked in the upcoming centuries. They also projected that carbon dioxide emissions could raise the average surface temperature of the earth by as much as 4°C during the next century (1963-2063)

Rising concern was also brought forth in 1965 when the President's Science Advisory Committee formed a panel to address environmental issues, including a climate change sub-panel. The 1965 meeting and report of this panel will be the subject of a future blog entry.

Dr. Keeling did have a monomania concerning carbon dioxide, but it was a productive monomania. Dr. Keeling was made professor of oceanography at the Scripps Institute in 1968, and received many honors for his scientific work. A short list of some of the honors he received:

Second Half Century Award of the American Meteorological Society, 1981
Maurice Ewing Medal of the American Geophysical Union, 1991
Blue Planet Prize from the Science Council of Japan and the Asahi Foundation, 1993
National Medal of Science, by George W. Bush in 2002
Tyler Prize for Environmental Achievement in 2005 (shared with Lonnie Thompson)

Dr. Keeling married Louise Barthold in 1955, and they had 5 children. One of whom, Dr. Ralph Keeling, is a climatologist at the Scripps Institute himself, following in his father's footsteps. Dr. Ralph Keeling is the current director of the Scripps CO2 Program.

Dr. Keeling was a lifelong Republican, of a type we don't see much of anymore--a Republican with a strong concern for the environment and science. Dr. Keeling deeply regretted and was disappointed by the politicization of science, and the abandonment of science by the large parts of the Republican party during the last two decades of his life. When ideology and scientific fact conflict, it should be the ideology that changes--because the facts will not. Dr. Keeling continued his measurements of carbon dioxide until he died of a heart attack on June 20, 2005.

A picture of Dr. Charles Keeling in 1997:

Here is the latest Keeling Curve, with the full record of carbon dioxide levels in the atmosphere:

A report released today (May 30, 2011) by the IEA reports that our CO2 emissions reached a new record in 2010, 30.6 billion tons. CO2 emissions in 2010 were 5% higher than the previous record in 2008.