Global Aging & Africa's Divergence

I recently completed an analysis focused on population aging, population age categories in % (age pyramids), and overall population growth.  It looks at various geographic units (countries, continents, regions, World) from 1950 to the Present (2019 & 2020).  And, it looks at projections out to 2100.  

 

I used data sourced from the UN Population Division.   

 

The main takeaway is that Africa is an outlier to the overall global aging; its population growth (historical & projected) is far faster than for other major regions. 

 

You can read the complete study at the following link: 

Global Aging at Slideshare 

 

... or a slightly shorter version at the following link:

Global Aging at Slidesfinder 

 

The above study consists of a Powerpoint with close to 60 slides.  It is very visual, and easy to digest.  But, as an intro to the whole thing, I will share a few highlights below by illustrating some of the key slides.  

First, let's disclose the three types of age pyramids.  Age pyramids are an aesthetic way of visualizing the population age profile of a country.  

 

A young population has a sharp looking pyramid with a large foundation (large youth base associated with high fertility) and a very sharp top (few elderly, short life expectancy). 

We can articulate an explanatory model that describes the process of global aging.  As women get more educated, they participate in the labor force.  And, fertility drops, life expectancy increases, population growth slows down, and population ages.

Within the full presentation, I share a ton of visual data that supports many of the variables' relationships defined in the model. 

This model explains how a population pyramid evolves from looking like a pyramid (young) to a urn (old), as shown below. 

 

The graph below compares the age pyramid of Nigeria, Brazil, and Japan in 1950 and in 2019. 

 

Back in 1950, the three countries' respective age pyramids looked nearly identical.  But, in 2019 they look radically different.  Nigeria's age pyramid has not changed since 1950.  It is still depicting a very young population.  Meanwhile, in 2019 Brazil's population pyramid looks very mature; and, Japan's looks very old. 

 

The population of Nigeria has grown from 37.9 million in 1950 to 206.1 million in 2020; and is projected to reach 793.9 million by 2100!

This historical and projected explosive population growth is true not only for Nigeria but for the whole of Africa.  Africa's population has grown from 0.23 billion in 1950 to 1.34 billion in 2020; and is projected to reach 4.47 billion in 2100!

 

Africa's continued explosive population growth is truly divergent when compared with any other large region. 

 

By comparison, see how Europe's population has already peaked by 2020, and is projected to decline out to 2100.  This is a picture of ongoing population aging.   

Population aging is even more pronounced for China.  Its population is expected to peak before 2040, and decline rapidly out to 2100. 

 

The table below discloses the population growth (historical and projected) for Africa and a few other major regions with population of more than 1 billion in 2020.

 

 

Notice how all four regions have a fairly similar population size in 2020.  However, by 2100 Africa's population is projected to be 3 to 4 times larger than the other regions!

 

And, this is how these regions share of the World population will change over the reviewed time periods. 

 

Next, let's compare Africa vs. the remainder of the World, excluding Africa.  

 

The World's population is projected to increase from 7.79 billion in 2020 to 10.88 billion in 2100.  And, the entire growth in the World's population is due to Africa.  The remainder of the World's population is projected to remain perfectly flat at around 6.4 billion.

 

Will we likely keep temperature increase at or below + 1.5 degree Celsius by the end of the Century?

 The short answer is that it is most unlikely that we will be able to do so.  

As we speak our global temperature is already at about 1.1 degree Celsius (over the average from 1850 - 1900).  So, we have only 0.4 degree Celsius to play with. 

Over the past 40 years, our temperature has risen by 0.7 degrees.  If the past is representative of the future, this suggests that over the next 23 years our temperature may very well increase by 0.4 degree over current levels.  And, going forward we would cross the + 1.5 degree threshold.   

This back of the envelope estimate is very much in line with the most recent scenarios generated by the IPCC, as shown below.

It is also in line with a forecast generated by a Vector Autoregression (VAR) model I had introduced in a recent post, as shown below. 

Thus, as described using three completely different methods ranging from rudimentary to pretty complex, we are most likely to run into trouble during the 2040s when we well could cross that + 1.5 degree Celsius threshold. 

One can still advance the argument that going forward everything will change.  We are decarbonising our World economy, etc.  

Well, the U.S. International Energy Agency (IEA) most recent forecast is really not encouraging on this ground.  They foresee a continued rapid rise in CO2 emission that will contribute to ongoing temperature rise. 

 

 

 

 

Quoting the EIA: 

“If current policy and technology trends continue, global energy consumption and energy-related carbon dioxide emissions will increase through 2050 as a result of population and economic growth.

 

Oil and natural gas production will continue to grow, mainly to support increasing energy consumption in developing Asian economies.”

 

If you want more information on this topic, please view the link to my presentation on the subject. 

2100 Temperature Forecast

 

 

Are we collapsing (in Southern Marin county)?

Jared Diamond, historian and author of “Collapse”, states that civilizations big and small have collapsed in good part because of exhaustion of water resources combined with out-of-control population growth. 

We are following Diamond’s exact recipe for collapsing by doing the following: 

1)    The Marin Municipal Water District (MMWD) Board only opting for building a water pipeline, that they are already planning to dismantle before it is even built to save money when they anticipate we won’t need the pipeline anymore;  

2Many customers of MMWD not willing to cut back on landscape irrigation to preserve the aesthetic and value of their home; 

3)   Because of environmental regulations we are diverting the equivalent of nearly 50% of our entire water consumption from MMWD to save the salmon.  We can’t ruin our local fisheries; and

4)    Sacramento is mandating we build thousands of units for low-income, local working population, and market units to facilitate necessary housing to accommodate the Bay Area job growth.

 Notice that each of the above actions make perfect sense on a stand-alone basis and out of the current context.  In combination, they will contribute to chronic water crises. 

Climate Change Models

 I am just sharing here some climate change models.  The main objectives included: 

1) being able to fit the historical World temperature data; 

2) being able to forecast World temperature using true out-of-sample or Hold Out testing; and 

3) being able to demonstrate causality between CO2 temperature concentration and temperature level. 

The models disclosed within this following link:

Climate Change Models 

... were surprisingly successful in meeting objectives 1) and 2).  They did very well at fitting the historical temperature data and forecasting temperature (out-of-sample).  By just using CO2 concentration (in either nominal or log transformation) as the main independent variable, the models could reasonably accurately estimate or predict temperature level.  

The most surprising model was a Vector Autoregression (VAR) model using just one single lag (1-year lag given the yearly frequency of the data).  And, this same model using historical data up to 1981 was able to predict reasonably accurately yearly temperatures from 1982 to 2020!  In decades of modeling time series, I have never encountered a model that works so well (either developed by myself or anyone else).  The most surprising thing is that this same VAR model does not even use the known values of the independent variable (natural log of CO2 concentration) from 1982 to 2020.  Without feeding any information to the VAR model over the out-of-sample period, it still could predict temperature pretty well.  

Notice how the VAR forecast over the 1982 to 2020 period is typically much under + or - 0.2 degree Celsius off.  

Going back to the third objective of the climate change models regarding confirming statistical causality between CO2 concentration and temperature, the modeling results using Granger causality methodology were far more humble.  Establishing Granger causality was rather challenging.  This was probably due to the temperature level variable being so autocorrelated.  Notice that this was not a technical flaw within any of the developed OLS regressions or VAR models because the two variables were very much cointegrated (as tested using Cointegration regressions). 

Marin County Drought Analysis

 In the Summer of 2021, after a very low rainfall during the past 12 months Southern Marin County (just north of San Francisco) faced an imminent water crisis with potentially less than 12 months left of water supply.  I contacted our local water utility, the Marin Municipal Water District (MMWD), to obtain historical data regarding rainfall.  And, I provided to them this attached analysis.  

Drought Analysis

The MMWD Board indicated that this water crisis was due to unexpected historically low rainfall during the preceding 12 months.  Granted, the rainfall was the second lowest in the over 100-year history of the data.  Along, the same line they wrote in local paper editorials that this was due to abrupt change in the climate that they could not have foreseen.  

My analysis indicated that this explanation was flawed.  Since our local rainfall when viewed over several years had actually been much more abundant in recent times vs. during our local dry period that ended in the early 1950s.  

 Thus, the current water supply crisis is not due to climate change and increasingly dry conditions (drought over several years).  Instead, this water supply crisis is due to a water supply-management crisis.  The MMWD Board has failed to plan for any water supply backup in any form.  Every other week, the MMWD Board writes an editorial in our local paper of how we should conserve more, let our gardens die, take shorter showers, etc.  At time of this writing, they have finally considered redeveloping a pipeline that would allow the MMWD to import and purchase more water.  But, before this pipeline is even implemented, they are already considering how to dismantle it once "we don't need it anymore."  Note that this absurd lack of planning is not unique.  MMWD had built this same pipeline during a severe drought in the 1970s, only to dismantle it in the early 1980s ("when it was not needed anymore").  Granted at the time, MMWD was in part motivated by CALTRANS to do so.  But, you would have hoped that rational minds at the time could have easily convinced CALTRANS to not request dismantling this critically needed back up source of water.

Many other solutions have been suggested to the MMWD Board to shore up our back up water supply, including different variations of desalination.  Invariably, the Board turns those suggestions down as too expensive.  Meanwhile, they have successfully implemented desalination operations in many other localities in California including Santa Barbara and San Diego.  And, I bet their respective water rates are much lower than the ones from MMWD.   

The MMWD lack of vision reminds me of the prescient book by Jared Diamond "Collapse."  This famous anthropologist reviews throughout history how civilizations have disappeared.  Among the several key conditions associated with such "collapses", he mentioned: a) water scarcity and related mismanagement; and b) population growth exhausting resources. 

The MMWD Board has pretty much worked hard on both dimensions to make our little local civilization collapse.  While, they have chronically refused to plan and implement permanent water supply back up, as of this writing they still have not restricted new water hook ups to allow more residents to move in the area and exhaust our limited water supply faster.