Sustainability Math A Quantitative Literacy and Mathematics Resource for Instructors

With Europe in the news with record heatwaves we turn to the European Environmental Agency to get a sense of changes in temperature in Europe.  The graph here from their page Heating and cooling degree days shows changes in heating degree days (HDD) and cooling degree days (CDD) weighted by population.

Figure 1 further illustrates that HDDs and CDDs did not show a clear trend in the period 1950–1980. (The declining trend for CDDs shown in Figure 1 (right panel) is highly sensitive to the choice of start year). Since the beginning of the 1980s, however, Europe has started experiencing a markedly declining overall trend in HDDs, and a markedly increasing trend in CDDs, which points to a general increase in cooling needs and a general decrease in heating needs.

Several model-based studies agree that the projected changes in temperature reduce the total energy demand in cold countries, such as Norway, whereas total energy demand increases in warm countries, such as Italy or Spain. The studies also agree that increases or decreases in total energy or electricity demand at the national level as a result of climate change alone will be below 5 % by the middle of the century [iv]. Although these changes are rather minor, adaptation needs can arise from their combination with socio-economic changes (e.g. increased availability of cooling systems) and from changes in peak energy demand.

There is an interactive version of the graph here with a table option for the data.

The NSIDC has a Greenland Surface Melt Extent Interactive Chart. For the graph here we selected 2012, 2016, and 2019 (blue). There was an early peak this year on June 12, 2019. How is this data collected (from Greenland Ice Sheet Today – About the Data):

Near-real-time images are derived from gridded brightness temperatures (TBs) from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) passive microwave radiometer. The TBs are calculated for each 25 kilometer grid cell. An algorithm is applied to produce an estimate of melt or no melt present for each grid cell. The data, images, and graphs are produced daily.

The colored areas on the daily image map records those grid cells that indicate surface melt from the algorithm, as a binary determination (melt / no melt). The melt extent graph indicates what percent of the ice sheet area is mapped as having surface melt, again from the binary determination per grid cell, using the summed area of the melt grid cells divided by the total ice sheet area.

Learn more at the NSIDC Greenland Ice Sheet Today page.  The data that is used to create the graph here doesn’t appear to be easily accessible. If you are interested and email may do the trick.

A recent Guardian article, Photograph lays bare reality of melting Greenland sea ice by Alison Rourke and Fiona Harvey (6/17/19) has an excellent photo of sled dogs appearing to walk on water. The article provides some context related to Greenland and ice.

Climate.gov reports on the prediction by NOAA for the Gulf of Mexico hypoxic zone in the artcle Wet spring linked to forecast for big Gulf of Mexico ‘dead zone’ this summer by Rebecca Lindsey (6/18/19).

Last week, NOAA issued its annual forecast, saying that the summer dead zone—an area near the sea floor where there is little or no dissolved oxygen—may be just shy of 8,000 square miles in 2019, nearly as large as the record-setting area that occurred in 2017. The ecological impacts of the Gulf dead zone spread through the economy.

The hypoxic or ‘dead’ zone:

This spring surge in runoff feeds an overgrowth of algae and other plant-like microbes (phytoplankton) that live in the coastal waters. The algae eventually die and sink to deeper layers of the Gulf, where they are decomposed by bacteria. Like human breathing, decomposition uses up oxygen. Under the right conditions, the bottom waters become severely depleted in oxygen, suffocating fish and other marine life that can’t escape.

Is this normal?

Sediment cores dug up from the ocean floor indicate that a large, yearly dead zone is not a natural phenomenon in the Gulf of Mexico. Microfossils in the sediment layers from the years 1700-1900 include species that cannot tolerate hypoxic (low oxygen) waters, which is a good sign that oxygen stress wasn’t a widespread problem before the twentieth century.

The article has other interesting maps but doesn’t provide the data in the graph. The data might be acquired with an email to LUMCON.  The original NOAA post, NOAA forecasts very large ‘dead zone’ for Gulf of Mexico (6/12/19) has links to their water monitoring stations.

The NASA research feature Tropical Cyclones are Stalling More by Kasha Patel (6/619) reports on hurricanes that stall for two days or more near U.S. coasts (graph copied here).

In a study published on June 3, 2019, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) showed that North Atlantic hurricanes have been moving slower and meandering more from their average trajectory over the past seven decades. The result has been storms that stall more frequently and linger for longer periods of time near the coast, leading to more rainfall over confined locations.

A climate connection?

“There is some evidence that those large-scale wind patterns are slowing down in the tropics, where Atlantic storms usually start,” said Hall. “The storms are not being pushed as hard by the current that moves them along. That’s a climate change signal.”

One projected effect of climate change is that air masses will move more slowly around the world. As global temperatures rise, the Arctic is warming faster than the tropics—a phenomenon called Arctic amplification. As temperature differences between the tropics and high latitudes decrease over time, so will the difference in air pressure, leading to a reduction in winds.

The study linked to in the first quote has links to data and that study may be useful as classroom material.

EPI has its annual report on the prospects for 2019 high school grads.  Class of 2019 High school edition by Elise Gould, Julia Wolfe, and Zane  Mokhiber (6/6/19) has 17 key findings and 11 graphs with data.  For example, their graph here (figure I) gives hourly wages in 2018 dollars for high school graduates not enrolled in further schooling.  As compared to 2000 wages for men as well as Black high school graduates are lower; all other groups have gone up. In fact, Hispanics make more than all other groups, including White graduates.

A few other highlights from the key findings:

Asian Americans/Pacific Islanders are significantly more likely to have begun on the college path at this age than any other racial/ethnic group.

Young black high school graduates are roughly twice as likely to be unemployed as their white and AAPI peers.

Average wages for young high school graduates recently surpassed their 2007 level, but remain just below their 2000 level, representing two lost decades of wage growth.

Black students (that go on to college) take on a disproportionate amount of debt, in part because their families generally accumulate less wealth than white families.

The entire report is worth reading.

Related post: What are the prospects for high school grads?

How you answer the question of where do you buy your food probably says a lot about your socioeconomic status. The chart here is from the Business Insider article Here’s where Americans are buying their groceries by Hayley Peterson (6/21/17).  Note that CVS, Walgreens, Dollar Tree, and Dollar General each outsell Whole Foods, for example. Why does this matter? The recent Guardian article Fears grow over ‘food swamps’ as drugstores outsell major grocers by Gabrielle Cannon (6/4/19) provides context.

Shelf-stable options tend to be highly processed and high in fat, sodium and sugar. Where they are the easiest option available, communities experience higher rates of chronic illness, like diabetes, heart disease and cancer.

“Highly processed food makes you sick,” says William McCarthy, an adjunct professor of public health at UCLA. “CVS and other pharmacies make money selling highly processed, long shelf-life foods, because it is all convenient.” But, he says, his research has shown that it’s not just about having more healthy options.

Interestingly,

In a 2016 study, researchers stocked corner stores in “food swamps” across East Los Angeles with affordable produce, hoping to test whether food retail interventions could be successful. They weren’t. While perceptions of the stores and community accessibility changed, patrons continued to purchase processed food instead of the fresh stuff.

Grocery sales data is available for 2018 (estimated) from the Winsight Grocery Business article WGB, Kantar Reveal ‘The Power 20’ Retailers by Meg major and Jon Springer (7/17/2018). They estimate CVS as fourth in grocery sales with Dollar General and Dollar Tree at 12 and 17, respectively. The Guardian article links to a couple of studies with statistical information suitable for a stats course.

The Our World in Data article Does the news reflect what we die from? by Hannah Ritchie (5/29/19) provides data on causes of death, google searches, and media reports by the NYT and the Guardian. The graph copied here is for 2016. As you can see there is a big disconnect. Why does this matter?

Media and its consumers are stuck in a reinforcing cycle. The news reports on breaking events, which are often based around a compelling story. Consumers want to know what’s going on in the world — we are quickly immersed by the latest headline. We come to expect news updates with increasing frequency, and media channels have clear incentives to deliver. This locks us into a cycle of expectation and coverage with a strong bias for outlier events. Most of us are left with a skewed perception of the world; we think the world is much worse than it is.⁵

The article has four time series from 1999 to 2016 (2004 to 2016 for google searches) corresponding to each of the four categories in the chart here. The charts are interactive and the data is available.

Footnote 5 is worth noting and Factfulness in worth reading: There are many results which show we have a negative bias of global progress. Factfulness, published by the Roslings, is packed with public survey results of Gapminder’s Ignorance Test. The test shows that the vast majority of people get the most basic questions on global development wrong (nearly always thinking the world is in a worst state than it is).

NOAA has an online tool, Data Tools: Daily Weather Records, that has a summary of daily, monthly, and all time weather records for the last 7, 30, and 365 days, as well as month to date and year to date. For instance, so far this year there have been 12,868 daily precipitation records set in the U.S. There is also a tool to select a time period and event. For example, from 5/21/2019 to 5/27/2019 there where 757 daily high precipitation records set.  The tool provides a map (copied here for this query) and a list of the stations with sortable records. For instances, in this time period the most rain was in Pawnee, OK which had 9.52 inches of rain breaking the previous record of 3.20 inches set on 5/21/1977.

Some details about the data:

For a station to be considered for any parameter, it must have a minimum of 30 years of data with more than 182 days complete each year.

These data are raw and have not been assessed for the effects of changing station instrumentation and time of observation.

The Pew article A Rising Share of Undergraduates Are From Poor Families, Especially at Less Selective Colleges, by Richard Fry and Anthony Cilluffo (5/22/19) summarizes the change in the economic background of students from 1996 to 2016.

As of the 2015-16 academic year (the most recent data available), about 20 million students were enrolled in undergraduate education, up from 16.7 million in 1995-96.¹ Of those enrolled in 2015-16, 47% were nonwhite and 31% were in poverty, up from 29% and 21%, respectively, 20 years earlier.²

The rising proportion of undergraduates in poverty does not mirror wider trends in society. The official poverty rate for adults age 18 to 64 (12%) was similar in 1996 and 2016, suggesting that access to college for students from lower-income backgrounds has increased since 1996.

As the graph copied here shows:

The growth in the share of dependent students from families in poverty has been uneven across postsecondary education. Their growing presence has been most dramatic among less selective institutions.

The article has a eight charts, a methodology section, and links to the data sources.

The Census Bureau report Parental Mortality is Linked to a Variety of Socio-economic and Demographic Factors by Zachary Scherer (5/6/19) provides charts of deceased parent(s) by sex, race (chart copied here), and socio-economic status.

For example, among those ages 45 to 49, 26% have lost their mother, while 45% have lost their father. Along these same lines, 7 in 10 of those ages 60 to 64 have a deceased mother, while about 87% have lost their father.

For example, among those ages 35 to 44, 43% of those living below the FPL have lost one or both parents, compared to 28% for those living in households with an income-to-poverty ratio of at least 400% of the FPL.

Parental loss, which varies by race and socio-economic status, is often accompanied by psychological and material consequences. These statistics demonstrate the way these new SIPP data can help assess how socio-economic and demographic characteristics are associated with parental mortality in the United States.

There are two other charts and a link to the SIPP data source.