Sustainability Math A Quantitative Literacy and Mathematics Resource for Instructors

No, as can be easily seen by the graphic here copied from the NASA article There is No Impending ‘Mini Ice Age’ (2/13/2020). At the same time we won’t be seeing an ice age anytime soon:

This is called a “Grand Solar Minimum,” and the last time this happened, it coincided with a period called the “Little Ice Age” (a period of extremely low solar activity from approximately AD 1650 to 1715 in the Northern Hemisphere, when a combination of cooling from volcanic aerosols and low solar activity produced lower surface temperatures).

Even if a Grand Solar Minimum were to last a century, global temperatures would continue to warm. Because more factors than just variations in the Sun’s output change global temperatures on Earth, the most dominant of those today being the warming coming from human-induced greenhouse gas emissions.

The article has another time series of solar irradiance with a source.

A new interactive graph was posted which gives population by age and race as of October 2018. The data is from the Census Bureau page School Enrollment in the United States: October 2018 – Detailed Tables and collected from the excel files in Table 2. The hover information will provide the percent of the total as well as percent male and female of the group. Go to the Interactive Graph page and take a look.

The Climate.gov article Climate Change: Spring Snow Cover by LuAnn Dahlman and Rebecca Lindsey (2/14/2020) provides the answer as seen in their graph here.

This change is another example of a feedback loop.

About one-third of Earth’s land surface is covered by snow for some part of the year. The bright white covering affects global conditions by reflecting solar energy away from surfaces that would otherwise absorb it. Therefore, the earlier decrease in snow cover increases the amount of sunlight absorbed by Earth, and in turn, surface temperatures.

The article includes the data for the graph shown here.

The EPI article Schools are still segregated, and black children are paying a price by Emma García (2/12/2020) provides an overview of inequities in secondary schools. Figure B in the article is copied here and speaks clearly to issues of inequality by race. There is also a political perspective that the percentages hide. According to Table 2 on the Census Bureau page School Enrollment in the United States: October 2018 – Detailed tables, there were 1,214,00 13 and 14 year old black students and 6,058,000 white students. (Note 13 and 14 years of age is approximately 8th grade and the Census Bureau is 2018 data while the EPI graph here is 2017. ) What this means is that there are 1,214,000*0.724=878,936 black eighth graders in high-poverty schools and 6,058,000*0.313=1,896,154 white eighth graders in high-poverty schools, or over twice as many white student in high-poverty schools.

The EPI article has a total of four graphs with available data.

The Pew report  Views of Nation’s Economy Remain Positive, Sharply Divided by Partisanship (2/7/2020) provides the answer:

Currently, 81% of Republicans and Republican-leaning independents say the economy is excellent or good. These views have changed only modestly over the past two years. But between November 2016 (just before Trump’s victory in the presidential election) and March 2017 the share of Republicans with a positive view of the economy approximately doubled, from 18% to 37%. And by November 2018, they had doubled again, to 75%.

By contrast, Democrats’ assessments of economic conditions have changed only modestly since before Trump took office. Currently, 39% of Democrats and Democratic leaners say conditions are excellent or good. In November 2016, 46% had a positive impression of the economy.

The graph here is one of five in the report. The methodology section has more details and could be used in a statistics course.

The NASA Vital Signs of the Planet post Study Confirms Climate Models are Getting Future Warming Projection Right by Alan Buis (1/9/2020) reports

In a study accepted for publication in the journal Geophysical Research Letters, a research team led by Zeke Hausfather of the University of California, Berkeley, conducted a systematic evaluation of the performance of past climate models. The team compared 17 increasingly sophisticated model projections of global average temperature developed between 1970 and 2007, including some originally developed by NASA, with actual changes in global temperature observed through the end of 2017. The observational temperature data came from multiple sources, including NASA’s Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP) time series, an estimate of global surface temperature change.

The results: 10 of the model projections closely matched observations. Moreover, after accounting for differences between modeled and actual changes in atmospheric carbon dioxide and other factors that drive climate, the number increased to 14. The authors found no evidence that the climate models evaluated either systematically overestimated or underestimated warming over the period of their projections.

There are links to NASA data and graphs at the bottom of the post.

From the NOAA Global Climate Report – Annual 2019:

The year 2019 was the second warmest year in the 140-year record, with a global land and ocean surface temperature departure from average of +0.95°C (+1.71°F). This value is only 0.04°C (0.07°F) less than the record high value of +0.99°C (+1.78°F) set in 2016 and 0.02°C (0.04°F) higher than the now third highest value set in 2015 (+0.93°C / +1.67°F). The five warmest years in the 1880–2019 record have all occurred since 2015, …

The report contains summaries by region and has abundance of quantitative information such as:

North America was the only continent that did not have an annual temperature that ranked among its three highest on record. Overall, North America’s temperature was 0.90°C (1.62°F) above the 1910–2000 average, marking the 14th warmest year in the 110-year continental record. The yearly temperature for North America has increased at an average rate of 0.13°C (0.23°F) per decade since 1910; however, the average rate of increase is more than twice as great (+0.29°C / +0.52°F per decade) since 1981.

The graphic here is from NASA, NOAA Analyses Reveal 2019 Second Warmest Year on Record (1/15/2020). Time series data can be obtained from Climate at a Glance Global Time Series.

The Our World in Data post You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local by Hannah Ritchie (1/24/2020) provides the graph copied here. From the article:

As I have shown before, food production is responsible for one-quarter of the world’s greenhouse gas emissions.

Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO₂-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO₂-equivalents, respectively.

Transport is a small contributor to emissions. For most food products, it accounts for less than 10%, and it’s much smaller for the largest GHG emitters. In beef from beef herds, it’s 0.5%.

The article itself doesn’t have data, but there are links to related Our World in Data posts about food with data.

Transparency International has a yearly corruption perceptions index. The graph here is for 2019 (high score – lighter colors – clean, low score – darker colors – corrupt).

The Corruption Perceptions Index ranks 180 countries and territories by their perceived levels of public sector corruption, according to experts and business people. This year’s analysis shows corruption is more pervasive in countries where big money can flow freely into electoral campaigns and where governments listen only to the voices of wealthy or well-connected individuals.

At the bottom of the page is a link to download an extensive data set including a timeseries from 2012 – 2019.  Each country has a designated region and so one could compare corruptions by region in a stats course.

The Scientific American article A Simple Twist of Thermodynamics Could Lead to Greener Refrigeration by Sophie Bushwick (1/21/2020) reports about the Science paper Torsional refrigeration by twisted, coiled, and supercoiled fibers by Run Wang et. el. (10/11/2019), which is behind a paywall (the graph here is from that paper). From the Scientific American article:

For another example, picture a rubber band, which is made up of a bundle of fibers. In the early 19th century, researchers found that pulling one makes it feel warmer. This effect happens because stretching the rubber band aligns the fibers more neatly, with less disorder. For this decrease in entropy to occur, the object has to pull in energy, in the form of heat, from its surroundings. When the tension is released, the entropy increases again, and the band cools down.

From the abstract of the Science paper:

Refrigerators using entropy changes during cycles of stretching or hydrostatic compression of a solid are possible alternatives to the vapor-compression fridges found in homes. We show that high cooling results from twist changes for twisted, coiled, or supercoiled fibers, including those of natural rubber, nickel titanium, and polyethylene fishing line.

The Scientific American article has a couple of interesting animations. The Science paper is technical. I’m not sure how to use any of this in a math classroom. I’m posting this because it is really interesting.