Sustainability Math A Quantitative Literacy and Mathematics Resource for Instructors

The article in The Conversation 7.5 billion and counting: How many humans can the Earth support? by Andrew D. Hwang (7/9/18) provides some details.  The graph here, copied from the article provides population number and future estimates. 

For real populations, doubling time is not constant. Humans reached 1 billion around 1800, a doubling time of about 300 years; 2 billion in 1927, a doubling time of 127 years; and 4 billion in 1974, a doubling time of 47 years.

On the other hand, world numbers are projected to reach 8 billion around 2023, a doubling time of 49 years, and barring the unforeseen, expected to level off around 10 to 12 billion by 2100.

The article provides a link to download the data and discusses key points related to inequality. For example,

Wealthy countries consume out of proportion to their populations. As a fiscal analogy, we live as if our savings account balance were steady income.

According to the Worldwatch Institute, an environmental think tank, the Earth has 1.9 hectares of land per person for growing food and textiles for clothing, supplying wood and absorbing waste. The average American uses about 9.7 hectares.

These data alone suggest the Earth can support at most one-fifth of the present population, 1.5 billion people, at an American standard of living.

This article is useful for QL and Stats classes, as well as anyone that would like to use population data and/or discuss carrying capacity.

The EPI article Class of 2018 High school edition by Elise Gould, Zane Mokhiber, & Julia Wolfe (6/14/18) provides a thorough review.  Figure I from the report, copied here, shows 2000 and 2018 wages for high school grads not enrolled in further schooling by race and gender.

In 2018, young workers with a high school diploma have an average hourly wage of $11.85, which translates to annual earnings of around $24,600 for a full-time, full-year worker. This overall average masks important differences in wages by gender and race.

The report has 11 graphs each with data that can be downloaded along with the graph.  A few points from the article:

• Only 32% of 18-64 have a four year degree or more while 10.5% haven’t graduated high school. (see figure A)
• The percent of high school grads (18-21) that are employed and not enrolled has increased from 26% in 2010 to 31% in 2018. (see figure c)
• Over much of the last three decades, wage growth for young high school graduates has been essentially flat. (see figure H)

The first paragraph of their conclusion:

While there may be many reasons someone might choose to enter the labor force after high school rather than attend college, college should at least be a viable option; a person’s economic resources should not be the determining factor in whether they get to go to college. But, as things stand, the prospect of staggering debt may discourage students from less wealthy families from enrolling in further education or prevent them from completing a degree.

Also, why would we want to know this?  NASA’s Vital Signs of the Planet feature How wide are the world’s rivers?  by Adam Voiland (7/18/18) answers the questions.

Most scientists who study rivers rely on measures of discharge, the volume of water transported through a given cross-section of a river. Much less studied, though critically important, is a river’s total surface area, particularly for scientists trying to understand how carbon dioxide moves between rivers and the atmosphere.

The work has resulted in a  global database of river widths.  The map here, copied from the post, answers the main question:

The OECD (Organisation for Economic Co-operation and Development) defines poverty as an income below half the median household income. The chart here was created using the most recent year of data from the OECD poverty rate page .  The U.S. leads the pack with a rate of 17.8%, with Israel right behind at 17.7%. At the bottom are Denmark and Finland with rates of 5.5% and 5.8% respectively.  It is important to note, as the OECD does,

However, two countries with the same poverty rates may differ in terms of the relative income-level of the poor.

The data is available for more than OECD countries on their page and there is an interactive graph, but the graph can’t be dowloaded. The data and R script that created the graph here are available: csv file, R script.

Citation for data:OECD (2018), Poverty rate (indicator). doi: 10.1787/0fe1315d-en (Accessed on 11 July 2018)

On July 12 2017 Iceberg A68, a slab of ice 5,800 km in area and weighing more than 1 trillion tonnes, calved from Larsen C. (project Midas 7/19/17)  A year later, where is A68:

As can be seen in the satellite image animation, over the last year A-68 has not drifted far because of dense sea-ice cover in the Weddell Sea.

The iceberg has been pushed around by ocean currents, tides and winds, and its northern end has repeatedly been grounded in shallower water near Bawden Ice Rise. These groundings led eventually to further pieces of the iceberg being shattered off in May 2018.

The screen shot here is at the end of their image animation. Go to the report by MIDAS, Iceberg A68 one year on by Adrian Luckman, Martin O’Leary and Project MIDAS (7/9/18), and see the animation. Last post from sustainabiltiymath on Larsen C: Larsen C Update 7/5/17.

The article in the Conversation, Why is suicide on the rise in the US – but falling in most of Europe? by Steven Stack (6/28/18), tries to get at the story. The first chart (copied here), clearly shows that the suicide rate rose from 199-2015 overall and considerably more for the 45-54 age group (stats regression problem here).  There is a second chart showing changes in suicide rates in Western European countries:

However, suicide rates in other developed nations have generally fallen. According to the World Health Organization, suicide rates fell in 12 of 13 Western European between 2000 and 2012. Generally, this drop was 20 percent or more. For example, in Austria the suicide rate dropped from 16.4 to 11.5, or a decline of 29.7 percent.

The obvious question is why?

There has been little systematic research explaining the rise in American suicide compared to declining European rates. In my view as a researcher who studies the social risk of suicide, two social factors have contributed: the weakening of the social safety net and increasing income inequality.

The article has two more charts showing that the U.S. is low on Social Welfare Expenditures as a percent of GDP and is high on inequality. In all instances the data is available for download and there are links to the original sources.

The Washington Post article, Red-hot planet: All-time heat records have been set all over the world during the past week by Jason Samenow (7/5/18), provides a nice overview of the record setting heat during this past week (map posted here copied from the article).  In North America:

Montreal recorded its highest temperature in recorded history, dating back 147 years, of 97.9 degrees (36.6 Celsius) on July 2. The city also posted its most extreme midnight combination of heat and humidity.

Ottawa posted its most extreme combination of heat and humidity on July 1.

In Europe:

Excessive heat torched the British Isles late last week. The stifling heat caused roads and roofs to buckle, the Weather Channel reported, and resulted in multiple all-time record highs:

In the Middle East:

As we reported, Quriyat, Oman, posted the world’s hottest low temperature ever recorded on June 28: 109 degrees (42.6 Celsius).

Maps of temperature anomalies can be created for various time periods from NASA’s GISS Surface Temperature Analysis page. June isn’t available yet but it will be before long.  Monthly Global Climate reports are available from NOAA. June isn’t available yet, but here are two highlight from May:

The contiguous U.S. May 2018 temperature was 2.89°C (5.2°F) above the 20th century average and the highest May temperature since national records began in 1895. This value exceeds the previous record set in 1934 by +0.4°C (+0.7°F).

Europe had its warmest May since continental records began in 1910 at +2.76°C (4.97°F), surpassing the previous record set in 2003 by +0.92°C (+1.66°F). May 2018 marks the first time in May that the continental temperature departure from average is 2.0°C (3.6°F) or higher.

The Pew Research Center’s article Distinguishing Between Factual and Opinion Statements in the News by Amy Mitchell, Jeffrey Gottfried, Michael Barthel, and Nami Sumida (6/18/18) addresses this question and more.

A new Pew Research Center survey of 5,035 U.S. adults examines a basic step in that process: whether members of the public can recognize news as factual – something that’s capable of being proved or disproved by objective evidence – or as an opinion that reflects the beliefs and values of whoever expressed it.

We will focus on section 4 Americans overwhelmingly see statements they think are factual as accurate, mostly disagree with factual statements they incorrectly label as opinions. Odds are that a person who identifies a factual statement as opinion will also disagree with the statement (see table copied here).  For example,  41% of those surveyed said that Spending on Social Security, Medicare, and Medicaid make up the largest portion of the U.S. federal budget was an opinion and of those 82% disagreed with the statement.

This is an excellent article for a QL or Stats course as it is rich with data, graphs, and charts. You can also discuss why 41% of those surveyed thought a statement that is measurable (How much of the Federal budget goes to social security, medicare, and medicaid?) was an opinion.  The article also includes detailed information on their methodology and detailed tables of data.

Changes in 30 year temperature averages depend on where you live, but Climate Central’s New Normal: Temperatures Are Trending Up Across U.S.  (3/16/18) has graphs for major cities across the U.S. The one here is for the U.S.

Normal temperatures, generally defined to be the 30-year average at a location, are trending up across most of the U.S. Since 1980, the average continental U.S. temperature has risen 1.4°F.

This is a change in the 30 year average so that the value for 2017 is the average from 1988-2017. In other words, the climate is changing.  A nice primer on the difference between weather and climate can be found at the NSIDC Climate vs Weather page:

Weather is the day-to-day state of the atmosphere, and its short-term variation in minutes to weeks. People generally think of weather as the combination of temperature, humidity, precipitation, cloudiness, visibility, and wind. We talk about changes in weather in terms of the near future: “How hot is it right now?” “What will it be like today?” and “Will we get a snowstorm this week?”

Climate is the weather of a place averaged over a period of time, often 30 years. Climate information includes the statistical weather information that tells us about the normal weather, as well as the range of weather extremes for a location.

The Climate Central post has a drop down menu and you can choose the graph for the city closest to you to see how much your climate has changed.  They don’t post the data that was used to create the graphs, but you can find the data for a location near you. Try starting with this NOAA map (look for a future post on using this portal for local data). This could be a great stats project for students.