Technological Progress and Demographic Conversion

I have little faith in demographic conversion. Population is a problem we must find a way to manage, or it will manage us.

Figure 1. Data source: U.S. Census Bureau

The previous two posts have focused on the size of the world’s population and why it matters. This post will draw out additional implications.

In 7.4 Billion and Counting I reported that as of the date I wrote that post the world’s population was 7,409,620,694, and that it was increasing by more than 2 every second. That’s a million people every 4.8 days. I published Figure 1, which shows that for 11,000 years of human history, the population grew relatively slowly. In the last 250 years, however, it has spiked upward, and we added the last billion in only 13 years. What happened?

In Why Does World Population Matter? I reported that only two factors affect world population: births and deaths. If you want to add to world population, then you must either have more births or fewer deaths. Population spiked during the last 250 years because the death rate decreased, especially the rate of infant mortality. This change occurred because of improvements in farming, leading to an increased food supply, but especially because of improved public health and medical care: sewers, proper food handling and storage, immunizations, and advancements in childbirth – those sorts of things. With fewer people being removed from the world by death, but birth rates remaining the same, the population spiked.

Figure 2. An S-Curve Describes Population Growth Over Time. Source: Brodnick 2016.

In Why Does World Population Matter? I published Figure 2. It shows that over time population increases ever more rapidly until resource scarcity limits it. This point is called the carrying capacity. As population approaches carrying capacity, one of two things happens: individuals become too unhealthy to be able to bear children, or the death rate increases. Either represents a substantial uptick in misery and suffering.

The implication is that for any given level of resources, if left unchecked, population will expand to consume all of the available resources. If one wishes to avoid an increase in misery, suffering, and death, then only two options are available. One is to reduce the birth rate. The other is to increase the amount of resources available. Unfortunately, based on the same reasoning, once that new level is reached, then population will inevitably expand to the new carrying capacity, and misery will increase again. This tendency became known as the Malthusian Trap, named after John Malthus who originated the idea. Malthus wrote in the late 1700s, and he focused principally on the availability of food. In the 1960s, Paul Ehrlich adopted Malthus’s reasoning. Writing in the mid-20th Century, he expanded the analysis to include other environmental stresses besides food. Both Malthus and Ehrlich predicted imminent catastrophe from expanding human population.

Figure 3. Source: Our World in Data.

Aside from reducing the birth rate, the only other option is for technological progress to outrace population growth, to constantly increase resource availability faster than population increases. Both Malthus and Ehrlich believed that the race was about to be won by population growth. Both were wrong, at least in the short run. Humankind has proved remarkably adept at winning this race – so far, at least. Technological advances have increased food availability throughout the world, and also the availability of most of life’s necessities. To take only one example, despite the impression you get from the headlines, famine has not increased; if anything, it is at an all-time low (Figure 3).


Figure 4. Source: World Bank.

In the mean time, an interesting thing occurred: as standards of living increased, the birth rate decreased (Figure 4). In 2015, only 19.7 children per 1,000 people were born, compared to 36.1 in 1963. This trend is universal: data was available for 196 out of 217 nations, and in every one of them, the birth rate fell between 1960 and 2015. Demographers call this change demographic conversion, and attribute it to many factors. Perhaps primary among them are reduced child mortality and the availability of birth control technologies. If the chances are good that children will survive to adulthood, then you don’t have to have so many, and the ability to put that choice into action is available.



Figure 4. Data source: U.S. Census Bureau.

Some writers place great emphasis on demographic conversion, arguing that nothing needs to be done to control population; it will control itself as living standards improve. On the other hand, Figure 5 shows historical world population from 1950 to 2016, and projects it to 2050, with the historical data in blue and the projections in red. Looking carefully, a small flattening of the curve can be seen in the projected data. This is the vaunted demographic conversion. It is not evident in the actual historical data – it is only a projection. Look how small it is! Even if it occurs as projected, population will grow from 7.4 billion to 9.3 billion by 2050. If that is control, it is hard to imagine what uncontrolled means!


In Why Does World Population Matter? I reported on work at the Stockholm Resilience Center that suggests there are 9 ecological thresholds we cannot cross without degrading the capacity of the earth to support life. We have already crossed two of them, and are approaching others. It may be that technological progress has not actually been winning the race against population, but rather borrowing from the future to stave off disaster now.

I don’t personally find the theory of demographic conversion very comforting. I believe (and it’s a belief, not an established fact) that the environmental stresses piling up around the world indicate that we have already passed the carrying capacity of the earth. Ecological changes, such as the depletion of the oceans, destruction of coral reefs, species extinction, desertification, and climate change are signs that we actually are losing the race to outpace population growth. I believe that we not only have to reduce population growth, I believe we have to reverse it: we have too many people already.

To suggest such a thing is fraught. It offends people values, and it raises very thorny economic and social justice problems. But, I believe, we will either manage this problem or it will manage us via an increase in misery, suffering, and death.


Hasell, Joe, and Max Roser (2017) “Famines”. Downloaded 8/22/17 from:

Lam, David. 2011. “How the World Survived the Population Bomb: Lessons ffrom 50 Years of Extraordinary Demographic History.” Demography, 48(4):1231-1262. Downloaded 8/20/2017 from

World Bank. Birth Rate, Crude (per 1,000 people). Downloaded 8/20/2017 from

Historical World population data are from: U.S. Census Bureau. World Population: Historical Estimates of World Population.

Steffen, Will, Katherine Richardson, Johan Rockstrom, Sarah Cornell, Ingo Fetzer, Elena Bennett, R. Biggs, Stephen Carpenter, Wim de Vries, Cynthia de Wit, Carl Folka, Dieter Gerten, Jens Heinke, Georgina Mace, Linn Persson, Veerabhadran Ramanathan, B. Reyers, and Sverker Sorlin. 2015. “Planetary Boundaries: Guiding Human Development on a Changing Planet.” Science, 1/16/2015. Downloaded 8/13/2017 from

USA population data prior to 2000 are from U.S. Census Bureau. Part II. Population of the United States and Each State: 1790-1990.

USA population data for 2000 and later are from U.S. Census Bureau, Population Division. Table 1. Intercensal Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1 2010 (ST-ESTOOINT-01).

Why Does World Population Matter?


If world population exceeds the world’s carrying capacity, it will result in misery, privation, and death. Unfortunately, the world’s carrying capacity is not well known.

In the previous post, I reviewed some data regarding world population. In this post I will discuss reasons that population is an essential concern for environmentalists, and try to draw out some consequences of the data in the previous post. In doing so, I am going to concern myself with world population size, not with how the population is distributed among countries, states, age ranges, genders. races, or ethnicities.

Only two things affect the population of the world: the number of births and the number of deaths. Births add to the population, and deaths subtract from it. As long as they match each other, the population of the world will neither rise nor fall. But if more people are born or fewer people die, then population will grow. On the other hand, if fewer people are born or more people die, then population will shrink.

The world has a carrying capacity, that is, a maximum population that it can sustain over time. This carrying capacity is limited by the availability of food, water, habitat, and other necessities. If the population exceeds the carrying capacity, then some of the people will not be able to obtain the necessities they need. The result will be misery, illness, and even death.

Figure 1. An S-Curve Describes Population Growth Over Time. Source: Brodnick 2016.

Figure 1 shows an s-curve, which is the curve demographers use to describe population growth. At the start, the population is low, so there are very few adults to reproduce. Consequently, population grows slowly. As the population grows, however, more and more adults are available to reproduce, so the population grows faster and faster. The growth rate continues to accelerate until the population becomes so large that competition for necessities increases. As it becomes harder and harder to gain life necessities, more and more individuals are unable to obtain them, and population growth slows. There is an eventual point above which the population cannot be sustained over time, and this is the carrying capacity.

This rather bland description hides a terrible fact: population growth slows because individuals have difficulty obtaining the necessities they need to survive. The result is hunger, disease, malnutrition, and squalor – in short, misery, privation, and even death. The idea here is that for any given level of resources, the population will expand to the point where one of two things will occur: either individuals will not be healthy enough to reproduce, lowering the birth rate, or the death rate will increase to match the birth rate. Either is terrible to contemplate.

The world is never without misery and privation. So long as population is below the world’s carrying capacity, however, it results from our inability (or unwillingness) to distribute life’s necessities to all people. On the other hand, if the world’s population exceeds its carrying capacity, the misery and privation will occur because there is not enough to go around. The amount of misery and privation will skyrocket. It is even possible that such a large population would cause so much environmental stress that it would cause a general environmental collapse, resulting in a world that had a much diminished capacity to support life. Such an outcome is not certain, but it is possible.

Figure 2. Data source: U.S. Census Bureau

Figure 2 is repeated from the previous post. It shows historical world population going back to 10,000 BCE. It is easy to see that the general shape of the curve matches the left hand side of Figure 1. The implication is that at some point, the increase in population could result in a scarcity of resources, resulting in an increase in misery, privation, and death on a global scale.






Figure 3. Snowshoe Hare and Wolf Population Dynamics. Source: Swatski 2010.

Overpopulation, leading to a population crash, is a dynamic that has been seen with many animals: in times of plenty they multiply beyond the carrying capacity of their local environment, and then there is a huge die-off. One example would be snowshoe hares, as shown in Figure 3. The blue line represents the population of hares, which repeatedly spikes and crashes. The red line shows the population of wolves, which prey on snowshoe hares. Shortly after the hare population spikes, so does the wolf population. Shortly after the hare population crashes, so does the wolf population. The hares multiply because there are so few of them that food is abundant, and they thrive. As their number spikes, however, tragedy occurs: they consume all the available food and then starve; they get crowded together and diseases break out; and there are more wolves to eat them. The wolves multiply because their food source, the hares, becomes abundant. Nothing eats the wolves, however. They die off because their food supply (the hares) has crashed, and they starve. Also, the increased crowding makes them vulnerable to diseases, as it did the hares.

Humans, of course, consume more than food. We need many different kinds of necessities to sustain our modern way of life. Thus, our population strains the environment in many, many ways. Air pollution, water pollution, climate change, water scarcity, habitat destruction, species extinction, desertification, forest fire – all are made worse by the size of our population. The concern is that, if we have exceeded the carrying capacity of the earth, humanity will suffer a die-off

People have been trying to estimate the carrying capacity of the earth for more than 200 years, and their estimates have ranged from less than 500 million to 1 sextillion. Methods of estimation have grown in sophistication over the years, and most modern estimates put it between 8 and 16 billion.

Figure 4. Planetary Boundaries. Source: Steffen et al, 2015.

On the other hand, the Stockholm Resilience Centre has identified 9 essential ecological systems that must remain within certain limits. If the planet remains inside these boundaries, humanity can continue to develop and thrive. If the planet does not, they believe, the earth’s ability to support life will be greatly degraded. Their assessment of the planet’s status is shown in Figure 4. The 9 systems are like wedges of a pie. Inside the green circle represents the safe area, and the red circle represents the maximum limit that must not be exceeded. We have already violated the boundaries in 2 of the 9 areas: biogeochemical flows, and biosphere integrity. We are approaching the boundary in 2 others: land-system change and climate change. The scientists at the Stockholm Resilience Center believe that the 9 areas interact and are mutually dependent: if one of them goes beyond its boundary, it will cause an imbalance that will draw the others out of their boundaries, too. Thus, according to their research, we have already gone too far, and need to go back.

Whether their work is precisely correct or not, it requires no genius to understand that the world is experiencing unprecedented environmental stress. It is occurring despite the fact that population has yet to reach 8 billion. Thus, I feel that estimates of the worlds carrying capacity tend to be overly optimistic. They may be something like theoretical estimates that cannot be achieved in real life.

The fact that we are so severely stressing the world suggests that there are already too many of us. What the right number would be, I think nobody knows. But the above discussion certainly illustrates why population is an important concern for environmentalists. Our well being depends on not exceeding the earth’s carrying capacity, but we may have done so already.


Brodnick, Robert. 2016. Curves that Matter: S-Curve. Robert Brodnick.

Malthus, Thomas. 1798. An Essay on the Principle of Population. London, England: J.Johnson. Available online at The Electronic Scholarly Publishing Project,

Steffen, Will, Katherine Richardson, Johan Rockstrom, Sarah Cornell, Ingo Fetzer, Elena Bennett, R. Biggs, Stephen Carpenter, Wim de Vries, Cynthia de Wit, Carl Folka, Dieter Gerten, Jens Heinke, Georgina Mace, Linn Persson, Veerabhadran Ramanathan, B. Reyers, and Sverker Sorlin. 2015. “Planetary Boundaries: Guiding Human Development on a Changing Planet.” Science, 1/16/2015. Downloaded 8/13/2017 from

Swatski, Rob. “Boom-and-Bust Cycles.” BIOL 101 Chp 53: Population Ecology. Downloaded 8/14/2017 from

United Nations Environment Program, Global Environmental Alert Service. 2012. One Planet, How Many People? A Review of Earth’s Carrying Capacity. Downloaded 8/11/2017 from

U.S. Census Bureau. World Population: Historical Estimates of World Population.

Wikipedia. List of Famines. Viewed online 8/14/2017 at

People and More People!

The population of the world is more than 7.4 billion people.

Figure 1. Data source: U.S. Census Bureau

As I write (7/11/2017), the population of the world is 7,409,620,694. Actually, that’s a bit of a misrepresentation, for more than 2 people are added to the world every second, so even as I type the end of this sentence, the total is higher. By the time this post is published (10/5/2017), it will be 17.6 million higher.

Take a look at Figure 1 at right. It is a graph of world population over the history of civilization as estimated by the U.S. Census Bureau. It is one of those “hockey stick” graphs that scare environmentalists. For thousands of years the population of the world grew very slowly. Starting in the late 1600s or early 1700s, the rate of population growth began to quicken. The world population crossed 1 billion sometime just after 1800. It crossed 2 billion early in the 20th Century, 3 billion in 1959, 4 billion in 1974, 5 billion in 1987, 6 billion in 1999, and 7 billion in 2012.

That’s right, it took more than 11,000 years for the population to cross 1 billion, but in the following 200 years it grew by 6 billion. It took only 13 years for the last billion.

Figure 2. Data source: U.S. Census Bureau.

Figure 2 shows world population since 1950 in finer detail, and projects future population to 2050. In the chart, historical data is blue, projections are red. By mid-century, world population is projected to grow to 9.4 billion. The increase is remarkably consistent and relentless. If you look at the shape of the chart carefully, however, you can see a slight increase in the slope during the 1970s, and a slight flattening of the slope starting somewhere around 2025. The flattening is very slight, and world population is projected to increase by more than a billion in the 20 years from 2030-2050.



Figure 3. Data source: U.S. Census Bureau

Figure 3 shows the growth in world population since 1950 and projected to 2050. The blue line shows the number of people added each year, and it should be read against the left vertical axis. The red line shows the percentage growth rate each year, and should be read against the right vertical axis. Both lines peak and then decline. In terms of the number of people added each year, the peak came in 1988, when 87.3 million persons were added to the world. Since then, it has declined, though only very moderately, and 77.6 million persons were added in 2016. Percentage growth in population peaked in 1966, when world population grew by 2.2%. It has declined since then, and in 2016 the world added 1.1% to its population.

Demographers project that the decline in both trends will continue, and by 2050, world population will grow by 42.9 million persons each year, or 0.46%. While that is a 45% decline from the number added in 2016, it is still more than the population of even the most populated state in the USA (California) and more than 7 times the population of Missouri in 2010.

Figure 4. Data source: U.S. Census Bureau.

Figure 4 shows similar data for the United States. The data starts in 1790, the year the first national census was conducted. The blue line represents the population of the country, and should be read against the left vertical axis. The red line represents the growth rate, and should be read against the right vertical axis. The blue line curves upward – as the population grew, more people were available to reproduce, adding a larger number of people with each decade. In 2010 the population was estimated to be 309 million. The rate of growth has slowed however. When the country was small, even a little bit of immigration added a significant fraction to the population. After the country had grown, even though more people were being added, they represented a smaller fraction. In 2010 the population of the USA grew by 0.83%, but the number of people added was 27.2 million, the second largest for any decade (1990-2000 was the largest at 33.5 million). Think of it: though the percentage growth is small, in terms of people, we’re adding a state the size of Texas every 10 years!


Figure 5. Data source: U.S. Census Bureau

Figure 5 shows similar data for Missouri. Missouri first became a territory in 1810, so the chart begins with that year. Population is shown in blue, and should be read against the left vertical axis. The population growth rate is shown in red, and should be read against the right vertical axis. The population line for Missouri has a hump in it; the state grew very quickly during the mid-to-late 1800s. It has grown more slowly since then, and the population was about 6 million in 2010. For the same reasons as with the USA as a whole, the population growth rate was very fast when the state was small, but has slowed greatly, and in 2010 was 0.59%.

I will discuss some of what this data means in the next two posts.


For current world population: U.S. Census Bureau. U.S. and World Population Clock.

USA and Missouri data prior to 2000 are from U.S. Census Bureau. Part II. Population of the United States and Each State: 1790-1990.

USA and Missouri data for 2000 and later are from U.S. Census Bureau, Population Division. Table 1. Intercensal Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1 2010 (ST-ESTOOINT-01).

World population data are from: U.S. Census Bureau. World Population: Historical Estimates of World Population.

Damaging Weather Events in Missouri

Figure 1. Data source: Office of Climate, Water, and Weather Services.

Damage from sever weather in Missouri shows a different pattern than does damage nationwide. As Figure 1 shows, the cost of damage from hazardous weather events in Missouri spiked in 2007, then really spiked in 2011. Since then, it has returned to a comparatively low level. The bulk of the damage in 2011 was from 2 tornado outbreaks. One hit the St. Louis area, damaging Lamber Field. The second devastated Joplin, killing 158, injuring 1,150, and causing damage estimated at $2.8 billion. The damages in 2007 came primarily from two winter storms, one early in the year, one late. In both cases, hundreds of thousands were without power, and traffic accidents spiked.

In 2015 Missouri saw an increase in weather-related damage, primarily due to the flooding that struck between Christmas and New Years that year. There was similar flooding this year in April, so 2017 will likely see a similar increase.

Figure 2. Data source: Office of Climate, Water, and Weather Services.

Figure 2 shows deaths and injuries in Missouri from hazardous weather. Deaths are in blue and should be read on the left vertical axis. Injuries are in red and should be read on the right vertical axis. The large number of injuries and deaths in 2011 were primarily from the Joplin tornado. In 2006 and 2007, injuries spiked, but fatalities did not. The injuries mostly represented non-fatal auto accidents from winter ice storms. The fatalities in 1999 resulted from a tornado outbreak.

The Missouri data covers fewer years than the national data discussed in my previous post. It also covers all hazardous weather, in contrast to the national data, which covered billion dollar weather disasters.

While the national data shows a clear trend towards more big weather disasters, Missouri’s data does not. The Missouri data seems to reflect the kind of disaster that occurred and where it occurred. Tornadoes, if they hit developed areas, cause injuries, deaths, and lots of damage. Floods cause fewer injuries and deaths; damage can be significant, but it is limited to the floodplain of the river that flooded. Ice storms affect widespread areas; damages come mostly through loss of the electrical grid and car crashes, which cause many injuries, but fewer deaths.


Office of Climate, Water, and Weather Services, National Weather Service. 2016. Natural Hazard Statistics. Data downloaded 9/11/2017 from 2016. Historical Consumer Price Index (CPI-U) Data. Data downloaded 2/10/16 from

Missouri State Emergency Management Agency. Declared Disasters in Missouri. Viewed online 9/12/2017 at

Descriptions of specific weather events, if they are large and significant, can be found on the websites of the Federal Emergency Management Administration, the Missouri State Emergency Management Agency, and local weather forecast offices. However, in my experience, the best descriptions are often on Wikipedia.

Severe Storms on the Increase

The number of severe storms is increasing, and so is their intensity.

Figure 1. Source: NOAA National Centers for Environmental Information.

In the previous post I noted that Hurricane Harvey was one in a series of storms that have devastated Houston, and indeed, the country as a whole. I asked what is going on, and whether it has always been this way.

The National Centers for Environmental Information tracks weather disasters that cause over $1 billion in damages. Figure 1 shows how many there have been each year going back to 1980. The number varies from year-to-year, but over time there has been a significant increase – there weren’t any in 1987, but in 2011 there were 16. Through July 7, 2017, roughly half the year, there have been 9.

(Click on chart for larger view.)

In the chart, the colors represent different types of weather disasters. Storms are divided into 3 categories: winter storms, which involve ice and snow, tropical cyclones (like Hurricane Harvey or Tropical Storm Irene), and severe storms. This last category includes thunderstorms and tornadoes, as well as severe rain events like the ones that caused flooding in Missouri in December 2015 and April 2017. You can see that the increased number of billion-dollar disasters has come from an increase in the number of severe storms. It has not come from tropical storms or winter storms.

Figure 2. Data source: NOAA National Centers for Environmental Information.

Figure 2 shows the damage cost from billion-dollar weather disasters each year. The damage cost is adjusted for inflation. The chart shows that there are many years when the total cost is below $25 billion. However, there are also years where the amount of damage spikes. The year with the largest damage was 2005, when Hurricane Katrina devastated New Orleans and a wide swath of the Gulf Coast, and damage topped $213 billion. That’s quite a chunk of change. The second highest cost occurred in 2012, when Hurricane Sandy came ashore in New York. This year, 2017, only includes damage up to July 7, so it doesn’t include Hurricane Harvey or Irma. I have seen news stories that the cost of damage from Hurricane Harvey may reach $150 billion, and Irma will add billions more. By the time the year is done, the damage cost is likely to be the highest in history.


Figure 3. Data source: NOAA, National Centers for Environmental Information.

Figure 3 shows the number of billion dollar weather disasters by type (through 7/7/2017). Since 1980, there have been a total of 212. Severe storms have accounted for 42% of the events.








Figure 4. Data source: NOAA National Centers for Environmental Information.

Figure 4 shows the total costs of billion dollar weather disasters by type (through 7/7/2017). Since 1980 costs have totaled $1.24 trillion dollars, and tropical cyclones have accounted for about 47% of the total cost. Though they constitute the largest number of events, severe storms account for only 16% of the cost of damages. That is because such storms, while severe, affect relatively small areas. Tropical storms and droughts, on the other hand, affect much larger areas.





Figure 5. Miami Beach in 1925. Source: Miami Design Preservation League.

All of the highest cost years have occurred since 2004. The data is inflation-adjusted, so that should not be the reason. One possible reason not related to the weather is that there are more people living in harms way – the population living along the coast has grown, and sprawl has caused more of the landscape to be covered with development, increasing the likelihood that a severe storm will hit something and damage it. For instance, in 1920 the population of Miami-Dade County (the location of the City of Miami) was 42,753 (that’s right, less than 50,000). But in 2010 it was 2,507,362. In 1992, when Hurricane Andrew devastated Homestead, a small community southwest of Miami, the area between Miami and Homestead was mostly open agricultural fields. Today, just 15 years later, it has filled-in, and is one continuous urban area. This story has been repeated all along the coasts of America, and in many inland areas as well. (See here.)





Figure 6. Intensity of Tropical Storms. Source: Kossin et al, 2013.

But I think that’s only part of the story. The number of tropical storms striking the U.S. may not have increased, but their intensity has. Figure 6 shows the intensity of tropical storms in different regions of the world over time. LMI stands for the lifetime maximum intensity of the wind in a storm, in meters per second. The lines represent quantiles. The 0.9 line (pinkish-purple) means that 90% of all storms that year were less intense than that value. The 0.8 line (light blue) means that 80% of all storms were less intense than that value, and so on. The authors dropped trend lines on the chart for each quantile. In the North Atlantic, storms have increased in intensity a lot. Those are the storms that strike the East Coast and Gulf Coast of the United States.


Figure 7. Source:

Other kinds of heavy precipitation events are also on the rise, as I reported here. Figure 7 repeats a chart from that post showing the trend over time.

Scientists project that climate change will cause an increase in storm intensity and in heavy rain events. It seems that this is not a prediction for the future, it is already happening. One cannot say that any individual storm is caused by climate change, but storms like Hurricane Harvey, Tropical Storm Irene, and the April storm in Missouri are already “more common,” and are likely to be even more “more common” in the future.

Sources: Broadcase_Trends-in-heavy-precip_V2. National Climate Assessment 2014. Downloads, Graphics (Broadcast). Downloaded 11/13/2016 from

Kossin, James, Timothy Olander, and Kenneth Knapp. 2013. Trend Analysis with a New Global Record of Tropical Cyclone Intensity. Journal of Climate, 26, 9960-9976.

Miami Design Preservation League. Collins Ave. at 63rd Street in 1925.Downloaded 9/8/2017 from

NOAA National Centers for Environmental Information (NCEI). U.S. Billion-Dollar Weather and Climate Disasters (2017).

Wikipedia. Miami-Dade County, Florida. Viewed online 9/8/2017 at,_Florida#2010_U.S._Census.

Hurricane Harvey Devastates Houston

Hurricane Harvey caused record flooding in Houston. Those poor people!

Figure 1. Flooding in Port Arthur, TX, from Hurricane Harvey. Source: South Carolina National Guard, 2017.

Most of you know about the terrible disaster that Hurrican Harvey caused in Houston, TX. The disaster will inevitably be compared to Hurricane Katrina and the flood that struck New Orleans. In both cases, a major city was flooded by a hurricane. Houston, however, is a metropolitan area with a population of about 6.3 million people, while New Orleans is a metropolitan area with a population of about 1.3 million. That means that Houston is almost 5 times as large.

New Orleans flooded so catastrophically because much of the city is below sea level. The levies broke, the ocean poured through, and the low areas filled up with water just like a bathtub would. Coastal Texas is a flat, low-lying area, some of which was swamp or marshland before being developed. It is not below sea level, however. Houston flooded because Hurricane Harvey dumped prodigious amounts of rain on the city – more than 4 feet of rain in some areas. The water couldn’t run off fast enough, and flooding occurred. The tragedy has been well covered by all of the national news sources, so I have contented myself with a single photograph of the flooding in Port Arthur, a small city about 100 miles northeast of Houston. (Figure 1) This blog focuses not on individual events, but on trends and on the big picture.

(Click on photo for larger view.)

Figure 2. Flooding in Houston from Tropical Storm Allison in 2001. Source: Harris County Flood Control District.

Houston has been hit repeatedly by tropical storms and hurricanes. From 1836 to 1936, the city suffered through 16 major floods, with the water level reaching as high as 40 feet in one of them. Since 1935, there have been 8 more. In 2001, Tropical Storm Allison dumped up to 35 inches of rain on Houston over 5 days, resulting in flooding that damaged over 73,000 homes and caused $5 billion in property damage (see Figure 2). In 2008, Hurricane Ike passed directly over the city, breaking out windows in downtown skyscrapers and wiping out electricity to some customers for over a month. Over the Memorial Day Holiday in 2015, rain of up to 11 inches over 24 hours drenched Houston, flooding thousands of homes. In April 2016 (last year), a trough of rain parked over the city, and over 24 hours, 17 inches of rain fell. They had to rescue 1,800 people from the floods, but even so 8 died and 1,144 homes were inundated.

But flooding is not limited to Houston. In April of this year, flooding in Missouri and Arkansas caused $1.7 billion in damages. In February, flooding in California caused $1.5 billion in damages, including Oroville Dam (see here). In October, 2016, Hurricane Matthew churned along the Atlantic Coast causing damage. In August, 2016, Louisiana received 20-30 inches of rain from a stationary storm, causing $10.3 billion in damages. And a December 2015 storm brought record flooding to Missouri and tornadoes to Texas, causing 50 deaths and $2.5 billion in damages. The list goes on and on.

Figure 3. Hurricane Irma Devastated the Island of St. Maarten. Photo: Gerb van Es, Dutch Department of Defense.

UPDATE: As of 9/8/2017, three more tropical storms have formed in the Atlantic Ocean: Hurricane Irma, a Catagory 5 hurricane (the largest category), passed over several Caribbean islands causing terrible damage (see Figure 3). As I write, it is bearing down on Florida. How bad will it be? We don’t know; it has diminished to a Category 4 hurricane, but it is wider than the Florida Peninsula is, and it is currently forecast to travel south to north right up the entire peninsula. Tropical Storm Jose is gaining strength in the mid-Atlantic, threatening many of the same islands that were just devastated by Irma, though it is forecast to turn north. And Hurricane Katia has formed just north of the Yucatan Peninsula, and is expected to come ashore north of Veracruz, Mexico.

What is happening? Has it always been this way, or is there more very damaging weather than there used to be? The next post will look at the national trend, and the post after that will look at the trend in Missouri.


Gerb van Es, Dutch Department of Defense. Aerial Photo Shows the Damage of hurrican Irma in Phillipsburg, on the Dutch portion of the Caribbean Island of Sint Maarten. Downloaded 9/8/2017 from

Harris County Flood Control District. Harris County’s Flooding History. Viewed online 8/30/2017 at

Harris County Flood Control District. Tropical Storm Allison. Viewed online 8/30/2017 at

NOAA National Centers for Environmental Information (NCEI) U.S. Billion-Dollar Weather and Climate Disasters (2017).

South Carolina National Guard. 8/31/2017. Image #170831-Z-AH923-081. Downloaded 9/8/2017 from

Wikipedia. April 2016 United States Storm Complex. Viewed online 8/30/2017 at

Wikipedia. Houston. Viewed online 8/30/2017 at

Wikipedia. New Orleans. Viewed online 8/30/2017 at

The Legacy of Abandoned Mine Lands in Missouri – Update 2017

Figure 1. Source: Office of Surface Mining Reclamation and Enforcement.

The previous two posts have reported on the amount of abandoned mine land in Missouri and neighboring states, how much of it is high priority, how much of it has been reclaimed, and how much remains to be reclaimed.

Coal has been one of the world’s most important industrial fuels, and for most of the last 100 years it has been the primary fuel from which we generate electricity. One of the reasons America grew to be an economic powerhouse was because we had abundant energy resources, and coal was one of them. West Virginia, Kentucky, Illinois, and Pennsylvania are currently the largest producing eastern coal states, in that order. Because their coal is high in sulfur, however, some coal production moved to the West, where the coal is lower in sulfur. Wyoming is now the nation’s largest coal producer, producing 39% of the nation’s coal.

Missouri is a coal producing state, though our production has been small compared to the high producing states. As Figure 1 shows, a significant portion of the state is underlain by coal. The majority of the coal veins are thin, however, and tend to be high in sulfur. Thus, coal mining never became the huge industry that it did in some other states.

Figure 2. Source: Office of Surface Mining Reclamation and Enforcement.

Coal mining began in Missouri in the 1840s. It peaked in 1984, when almost 7 million tons were mined. But since then, production has trended lower, and 138,206 tons were mined in 2015, only 2-3% of peak production. In contrast, Wyoming mined 387.9 million tons, hundreds of times more. Figure 2 shows the trend since 1994. Currently, the coal used to generate Missouri electricity is about 90% Wyoming coal, 10% Missouri coal.

Other kinds of mining began in Missouri even earlier, as early as the 1740s. At one time, Missouri was the primary source of lead in the United States. As many as 67,000 acres of unreclaimed land were abandoned by the coal industry, and 40,000 acres by other mining operations.

Missouri’s land reclamation program was established by state law in 1974, when the Department of Natural Resources was created. But it got a big boost with the passage of the federal Surface Mining Control and Reclamation Act in 1977. This law provides minimum requirements for mines, funding, and oversight of state reclamation efforts.

As we saw in the previous post, some states have an abandoned mine land problem many times greater than does Missouri, and their reclamation efforts receive higher levels of funding than does ours. Funding has varied from year-to-year with budgetary woes and shifting priorities. But Missouri and other states have been working to reclaim abandoned mine lands since the 1970s. As we saw in the two previous posts, abandoned mine lands are classified into 3 broad categories. Lands that pose an extreme danger to health and welfare are classified Priority 1, and lands that pose a threat to health and welfare are classified as Priority 2. Land that has been degraded by mining operations, but which is not a threat to health and welfare, is classified as Priority 3. Priority 1 and 2 lands are classified as high priority. The law requires their reclamation before Priority 3 lands are addressed. In addition, the law requires abandoned coal mining land to be addressed before other types of abandoned mine lands, I’m not quite sure why.

Since the 1970s, mining operations have been required to obtain state permits in order to operate. Miners must pay a fee for the permit, and place a bond with the state, and they are required to reclaim their land when mining operations finish. Should they fail to reclaim the land, the bond is forfeited, and the funds are used by the state for its reclamation efforts. Because there is less coal mining in Missouri, fees collected by the Department of Natural Resources have decreased, and this is one reason that the funds available for reclamation have also decreased. (Missouri Department of Natural Resources, 2014)

As reported in the previous 2 posts, Missouri has made significant progress in reclaiming its abandoned mine land. But it is a very, very big and expensive job. Because the units to be reclaimed can be of so many different types, and because funding levels control the rate of reclamation, I think that estimated costs may give the best picture of what’s been accomplished and what remains to be done. By cost, Missouri has completed about 1/3 of its work to reclaim Priority 1 and 2 land. However, that does not include Priority 3 land. At the 2014 funding level, it will take Missouri 3-4 decades to complete reclamation on Priority 1 and 2 land, and about 8 decades to finish the job completely. Unfortunately, not all abandoned mine lands have been inspected. As they are, unless Missouri devotes more resources to the job, the time to completion is likely to grow.


U.S. Energy Information Administration. 2015. Frequently Asked Questions: Which states produce the most coal? Viewed 4/16/2015.

Alton Field Division, Office of Surface Mining Reclamation and Enforcement. 2017. Annual Evaluation Report for the Regulatory Program and the Abandoned Mine Land Program Administered by the State Regulatory Authority of Missouri, For Evaluation Year 2016.. U.S. Department of the Interior.

Missouri Department of Natural Resources. 2014. 2012-2013 Land Reclamation Program Biennial Report.

Missouri Department of Natural Resources. 2016. 2014-2015 Land Reclamation Program Biennial Report.

High Priority Abandoned Mine Lands Spike in 2017

The amount of dangerous highwall in Missouri spiked in 2017, leading to a large increase in uncompleted high priority abandoned mine units needing reclamation.

Table 1. Data source: Office of Surface Mining Reclamation and Enforcement.

The previous post concerned the total inventory of abandoned mine lands in Missouri. This post focuses on high priority abandoned mine lands: those that pose an extreme danger to public health and safety (Priority 1) and those that pose a threat to public health and safety (Priority 2). The law requires Missouri to reclaim high priority lands before low priority lands.

Table 1 shows the data for August 2017, April 2015, and April 2014. Completed units increased across all three dates, as one would want. However, uncompleted units grew between 2014 and 2015, and then spiked between 2015 and 2017 by 384%. This resulted in a similar pattern for total units: they increased between 2014 and 2015, and spiked between 2015 and 2017.

Reviewing the categories of hazards (not shown), most categories increased modestly between 2015 and 2017. However, units of dangerous highwall increased from 11,350 to 160,924. There are several possible reasons for such a drastic change. I cut and paste my data from the database, and I have made several checks with the e-AMLIS database to ensure I did not make an error, and I don’t think I did. However, there may be a data entry error in the online database itself. Alternatively there may have been a change in the way units of highwall are counted that is not described in the database information. Missouri could have inspected mine lands that had not been previously inspected, resulting in the discovery of additional dangerous highwall. Finally, known highwall that was not unstable may have become unstable during the period.

Figure 1. Data source: Office of Surface Mining Restoration and Enforcement.

Completed costs have also grown at each date, indicating the reclamation work that has been completed. Uncompleted costs, however, have grown even more quickly, and in 2017 they were more than 6 times what they were in 2014. This is unlikely to be a data error; more likely, it represents an improved estimate of what the costs will actually be, combined with inflation.

The Figure 1 shows the number of Priority 1 and 2 units for Missouri and 5 neighboring states. Blue represents completed reclamation, red represents uncompleted. Don’t forget that a unit can be acres of spoiled land, individual buildings or structures, hazardous bodies of water, vertical openings, or lengths of dangerous highwall, so one cannot directly translate number of units to environmental threat or cost to reclaim.




Figure 2. Data source: Office of Surface Mining Reclamation and Enforcement.

The Figure 2 shows the estimated costs to reclaim Priority 1 and 2 sites for those same states. Blue represents completed work, red represents uncompleted. This chart may be a more informative representation of the amount of work accomplished so far, and the amount yet to do. It shows that in terms of costs, Missouri has completed about 1/3 of the work required to reclaim its high priority sites. Arkansas has completed more than 2/3, Illinois not quite 1/2, and Iowa not quite 1/2. Kentucky, a big coal mining state, has had a larger reclamation challenge, but even they have completed more than half of the work. Kansas, on the other hand, has completed about 1/17 of the work. They are just getting started. (e-AMLIS Database, 2015)

Pennsylvania is the state with the largest amount of abandoned mine land, and the state with the largest reclamation challenge. They have more than 10 times as many Priority 1 and 2 units as does Missouri, and the estimated cost to reclaim them is $4.8 billion, some 29 times as much as Missouri’s cost. (e-AMLIS Database, 2015)

Figure 3. Data source: Office of Surface Mining Reclamation and Enforcement.

The Figure 3 shows changes in the number of uncompleted units and uncompleted costs. Changes in Arkansas, Illinois, Iowa, and Kentucky were small. The large changes in Missouri have been discussed above. Kansas had small increase in the number of units, but a large increase in costs. As in Missouri, my guess is that the change represents improved estimation of the costs involved plus inflation.

In my next post, I will report on some other interesting facts in the most recent reports on abandoned mine lands.


Office of Surface Mining Reclamation and Enforcement. e-AMLIS Database. I used the Summary, and selected State/Tribe = Missouri.

For other abandoned mine land sources, see previous post.

Abandoned Mine Lands Increase Yet Again

The amount of abandoned mine land needing reclamation has grown every year I have looked at it.

Figure 1. Data source: Office of Surface Mining and Reclamation e-AMLIS database, 2017.

Between April 2015 and August 2017 the number of units of abandoned mine land in Missouri increased by 0.75% according to a federal database (e-AMLIS, 4/15/2015). The data is shown in Figure 1: blue represents land on which reclamation has been completed, red represents land funded for reclamation but not completed, and green represents land awaiting funding for reclamation.

(Click on graphic for larger view.)

Mines create environmental hazards if efforts are not made to prevent it. The hazards range from piles of material that can leach hazardous substances, to clogged streams, to polluted or hazardous water bodies, to vertical openings into which victims can fall, to dangerous walls, dams, and structures that can collapse.

The federal government keeps an inventory of identified abandoned mine lands, the e-AMLIS Database. There can be several units at one abandoned mine site. For instance, one might be a pile of tailings, another might be an abandoned building, and a third might be a highwall. The units of mine land in the statistics may refer to acres of spoiled land, number of unsafe structures, or lengths of unsafe highwall. You can’t translate directly from units to acres of land.

Figure 2. Source data: Office of Surface Mining Reclamation and Enforcement e-AMLIS database, 2017.

Figure 2 shows the location of abandoned mine lands in the e-AMLIS inventory in Missouri and in nearby regions of neighboring states. “Why,” a thoughtful reader might ask, “are these lands in southwestern and north-central Missouri? Isn’t the “lead belt” in southeastern Missouri?” Yes, of course it is. But these are surface lands, mostly from coal mining, and these are the locations where that kind of mining occurred.

Not all of Missouri’s abandoned mine lands have been inventoried, and I don’t know the status of the uninventoried land. Since the 1970s, mine operators have been required to restore mine land when mining operations cease. Compliance is enforced through a bonding system. Most of Missouri’s abandoned mine lands result from mines abandoned before the 1970s. The Missouri Land Reclamation Authority estimates that as many as 107,000 acres of mine lands have been abandoned in Missouri, about 0.2% of the entire state. (Missouri Department of Natural Resources, 2016, p.2) Since 1970, when a mine operator abandons the land, they forfeit their bond, and the state uses that money, plus appropriations, to reclaim the land. The decline of mining in Missouri has resulted in lower bond holdings, reducing the money available for reclamation.

During FY 2016, Missouri completed reclamation of 40 acres of clogged stream land, 74 acres of dangerous piles, embankments, and highwalls, 35 polluted or hazardous water bodies, 1 acre of industrial waste, 45 acres of mine spoils, and part of a hazardous vertical opening, at a cost of $1,319,499. (Alton Field Division, 2017, Appendix 1, Part B, Tables 2 & 3)

Over the history of the reclamation program, 39% of the high priority units have been reclaimed (more on that in the next post), but an estimated $109,512,447 of reclamation work remains unfunded. At 2016’s rate of spending, it will be 83 years before the work is finished. The last time I looked at this data, in April 2015, the time to complete the work was 75 years. Mine reclamation is a costly, long-term project.

The law requires that abandoned coal mines be reclaimed before other abandoned mines, and it requires high priority lands be reclaimed before low priority lands. Priority 1 lands (those posing an extreme danger to public health and safety) and Priority 2 lands (those posing a threat to public health and safety) are high priority. Priority 3 lands (those involving the restoration of land previously degraded by mining) are low priority. More on high priority abandoned mine lands in the next post.


Office of Surface Mining Reclamation and Enforcement. e-AMLIS Database. I used the Advanced Query, State = Missouri, County = All, District = All, Priority = All, Problem Type = All, Program = All, Funding = All, Mining Type = All.

For the map, I used the e-AMLIS Database, and I used the mapping function, which allows a map for Missouri to be produced. I created the map 8/6/2017.

Alton Field Division, Office of Surface Mining Reclamation and Enforcement. 2017. Annual Evaluation Report for the Regulatory Program and the Abandoned Mine Land Program Administered by the State Regulatory Authority of Missouri, for Evaluation Year 2016. U.S. Department of the Interior. Downloaded 8/3/2017 from

Missouri Department of Natural Resources. 2016. 2014-2015 Land Reclamation Program Biennial Report.

Green Buildings Are Better – Financial Performance

A study by the Department of Energy found that in green buildings net operating income was 28.8% higher than in non-green buildings. Missouri has more green buildings than Tennessee, but far fewer than Maryland.

The residential and commercial buildings in the U.S. consume about 40% of the nation’s total energy consumption. Green buildings use less energy, improve occupant health and productivity, and lower ownership risk. However, until recently researchers have lacked sufficient historical data to analyze the link between energy efficiency and financial performance because the information has been proprietary.

A recent study by the U.S. Department of Energy addressed this question. The authors were able to identify a set of 131 buildings for which the necessary data were available. Only buildings that met the following criteria were accepted into the study:

  • Market value per square foot was greater than $400.
  • Rent concessions in the building were greater than $0, but less than $3 per square foot.
  • Monthly rent in the building was greater than $6 per square foot.
  • Occupancy in the building was greater than 50%.

The authors then divided the buildings into two groups: buildings were “green” if they had an Energy Star score of 75 or higher (a measure of energy efficiency compared to other buildings of the same type) or if they had achieved LEED Certification. A discussion of what these criteria mean is below. Buildings were “non-green” if they did not meet either criteria. The result was 2 groups of buildings, green and non-green, each with more than 60 buildings in it.

The authors then compared the buildings on the following metrics:

  • Market value per square foot;
  • Net operating Income per square foot;
  • Operating expenses per square foot;
  • Rental income per square foot;
  • Rental concessions per square foot;
  • Occupancy rate.

Table 1. Comparison of Green and Non-Green Buildings on 6 Financial Performance Metrics. Source: Department of Energy, 2017.

Table 1 gives the results. Green buildings had higher market value, higher net operating income, higher rent, lower rental concessions, lower operating expenses, and higher occupancy rates. The differences in operating expenses and net operating income achieved statistical significance (p = 0.0089 and 0.0015 respectively), and the difference in market value approached it (p = 0.094).

Looking at Table 1, what jumps out is that net operating income was 28.8% higher in green buildings. Most of the increase seems to have come from reduced expenses, with a smaller contribution coming from increased rents.


Table 2. Source: Miller et al, 2008.

The Department of Energy study is not the only study to suggest better financial performance from green buildings. Table 2 summarizes results from 3 additional studies, all of which found that LEED and ENERGY STAR buildings generated higher rents, higher occupancy rates, and higher value per square foot.







Figure 1. Data source: Green Building Information Gateway

So how many green buildings are there in Missouri? A database operated by the U.S. Green Building Council lists 389 LEED certifications in Missouri, covering 35.27 million square feet. Tennessee, Missouri, and Maryland are the 17th, 18th, and 19th most populous states in the country. Tennessee has 377 LEED certified activities (48.35 million square feet), and Maryland has 964 (11.4 million square feet). Figure 1 shows the data, with the number of LEED certified buildings in blue and the LEED certified square footage in red. Clearly, green building has caught on in Maryland to a much greater extent than it has here. It’s too bad – if you could deliver health benefits to those who live and work in a building, while at the same time improving its net operating income by 28.8%, you’d think that you’d want to do that, wouldn’t you?

Explanation of Energy Star and LEED Certification: ENERGY STAR is a building energy benchmarking program operated by the U.S. Department of Energy. Building owners enter their building’s energy consumption (from utility bills and similar sources) into a computer database. The database then compares the building’s energy consumption to that of other similar buildings. In other words, hospitals are compared to hospitals, schools to schools, office buildings to office buildings, etc. The program then gives each building a rating from 1-100, the higher the number the better the building’s energy performance. LEED is an acronym that stands for Leadership in Energy and Environmental Design. To achieve LEED certification, a building must incorporate a suite of technologies that improve the building’s environmental performance in a number of areas, from energy consumption to indoor air quality to water consumption, and others. The LEED system is administered by the U.S. Green Building Council.

MoGreenStats is now going on break for a few weeks. The next post will be scheduled for August 24, 2017. Happy trails ’til then.


Department of Energy. 2017. Utilizing Commercial Real Estate Owner and Investor Data to Analyze the Financial Performance of Energy Efficient, High Performance Office Buildings. Downloaded 7/9/2017 from

Miller, Norm, Jay Spivey, and Andy Florance. 2008. Does Green Pay Off? Published by U.S. Department of Energy. Downloaded 7/10/2017 from

The Green Building Information Gateway, an online database operated by the U.S. Green Building Council. Data accessed online 7/9/2017 at