Sustainability Math A Quantitative Literacy and Mathematics Resource for Instructors

UCAR (University Corporation for Atmospheric Research) has The Very Simple Climate Model page with a climate model where you set the emissions and then run the model until 2100. You get graphs of carbon emissions, CO2 concentration, and temperature. For example, the output in the graph here set emissions at about half the current level. Even then temperature goes up a degree F by 2100. The model can be run 1 year at a time with different emissions each year. There is a link to an activities page as well as some scenarios to explore.

The NASA article Global Climate Change Impact on Crops Expected Within 10 Years, NASA Study Finds by Ellen Gray (11/2/2021) provides an answer:

Climate change may affect the production of maize (corn) and wheat as early as 2030 under a high greenhouse gas emissions scenario, according to a new NASA study published in the journal, Nature Food. Maize crop yields are projected to decline 24%, while wheat could potentially see growth of about 17%.

What is one mechanism for the decline?

Higher temperatures also affect the length of growing seasons and accelerate crop maturity.

“You can think of plants as collecting sunlight over the course of the growing season,” said Ruane. “They’re collecting that energy and then putting it into the plant and the grain. So, if you rush through your growth stages, by the end of the season, you just haven’t collected as much energy.” As a result, the plant produces less total grain than it would with a longer development period. “By growing faster, your yield actually goes down.”

The article includes a nice 2 minute video. For grain harvest data see the World Grain tile on the Statistics Projects page.

The Pew article Growing share of Americans say they want more spending on police in their area by Kim Parker and Kiley Hurst (10/26/2021) compares police spending polls from June 2020 and Sept 2021. The overall summary is in the graph copied here. There are other charts including a breakdown by race, ethnicity, age, and political leaning. For example,

Among Democrats, Black (38%) and Hispanic (39%) adults are more likely than White adults (32%) to say spending on police in their area should be increased. There is no significant difference across these racial and ethnic groups in the share of adults who say spending should be decreased.

Within the GOP, White and Hispanic adults differ in their views on this question: 64% of White Republicans say police spending in their area should be increased, compared with 53% of Hispanic Republicans.

Pew included a methodology section for both polls.

Our World in Data has, well, the data in their Crop Yields Data Explorer. For example, here is a chart of cereal yield for a few countries. With the crop yields data explorer you can select from most countries, different crops, and different measurements. In each case the data can be downloaded, as well as the chart.

According to the Pew article Citizens in Advanced Economies Want Significant Changes to Their Political Systems by Richard Wike, Janell Fetterolf, Channon Schumacher, and J.J. Moncus (10/21/2021) people seem to think we need to reform our pollical systems.

Across 17 advanced economies surveyed this spring by Pew Research Center, a median of 56% believe their political system needs major changes or needs to be completely reformed. Roughly two-thirds or more hold this view in Italy, Spain, the United States, South Korea, Greece, France, Belgium and Japan.

In the chart copied here, the U.S. is again near the top. In this case only Italy and Spain have a higher percentage saying they need change. There are over a dozen charts analyzing the issue of wanting political change in the article.

Our World in Data has an extensive post on Fish and Overfishing by Hannah Ritchie and Max Roser (first published Oct 2021). Here is one excerpt from this article:

In the chart here we see five centuries of cod catch in Eastern Canada.¹ These fishing records date back to the year 1500. We see that fish catch started to increase from around 1700 through to the mid-20th-century. It peaked in 1968, before a collapse in fish stocks led to a dramatic decline. In fact, fisheries were forced to close 24 years later, in the early 1990s. Since then, stocks have not been able to recover due to the reopening of fisheries and their overexploitation afterwards.

You can download the data for this chart and more than a dozen others in the post.

The Pew report Diversity and Division in Advanced Economies by Laura Silver, Janell Fetterolf, and Aidan Connaughton (10/13/2021) has the U.S. is the top spot in a poll and not in a good way.  The chart copied here from Pew has the U.S. at the top for conflict between political parties and even the second highest response from the U.S. would be third in the most common response.

Notably, however, in most societies racial and ethnic divisions are not seen as the most salient cleavage. Rather, in the majority of places surveyed, more people identify conflicts between people who support different political parties than conflicts between people with different ethnic or racial backgrounds. Political divisions are also seen as greater than the other two dimensions tested: between those with different religions and between urban and rural residents. (For more on the actual composition of each public surveyed on each of these dimensions, see Appendix A.)

The report has over 20 charts and rich context to discuss the quantitative results.

From NOAA’s Global Climate Report – September 2021:

The global surface temperature for September 2021 was 0.90°C (1.62°F) above the 20th century average of 15.0°C (59.0°F) and was the fifth highest September temperature in the 142-year record. Only Septembers of 2015, 2016, 2019, and 2020 had a higher September temperature departure. The eight warmest Septembers have all occurred since 2014. September 2021 also marked the 45th consecutive September and the 441st consecutive month with temperatures, at least nominally, above the 20th-century average.

Some regional highlights:

The Southern Hemisphere’s September 2021 surface temperature departure of +0.70°C (+1.26°F) was the warmest September in the 142-year record, surpassing the previous record set in 2018 by 0.02°C (0.04°F).

According to NCEI’s continental analysis, Africa had its warmest September on record at 1.50°C (2.70°F) above average, surpassing the previous record set in 2017 by 0.07°C (0.13°F).

September 2021 was also South America’s warmest September on record at +1.94°C (+3.49°F). This value exceeded the previous record set in 2015 by 0.23°C (0.41°F).

Time series data is available near the top of the page.

The Pew article What we know about online learning and homework gap amid the pandemic by Katherine Schaeffer (10/1/2021) has this to say:

Parents with lower incomes whose children’s schools closed amid COVID-19 were more likely to say their children faced technology-related obstacles while learning from home. Nearly half of these parents (46%) said their child faced at least one of the three obstacles to learning asked about in the survey, compared with 31% of parents with midrange incomes and 18% of parents with higher incomes.

This technology divide isn’t new:

Even before the pandemic, Black teens and those living in lower-income households were more likely than other groups to report trouble completing homework assignments because they did not have reliable technology access. Nearly one-in-five teens ages 13 to 17 (17%) said they are often or sometimes unable to complete homework assignments because they do not have reliable access to a computer or internet connection, a 2018 Center survey of U.S. teens found.

There are four other charts in the article.

The graph here is from the paper Co-production of knowledge reveals loss of Indigenous hunting opportunities in the face of accelerating Arctic climate change in Environmental Research by Donna D W Houser, et. el. (8/24/2021). From the discussion:

Overall, our analyses indicate that the ugruk harvesting season for Qikiqtaġruŋmiut hunters is being compressed by the shorter spring ice breakup period. Indeed, if we summarize across our time-series from 2003 to 2019, Kotzebue Sound now clears of sea ice ∼22 d earlier (figure S3) and is the primary factor contributing to a shrinking ugruk hunting season.

A new Indigenous-led study documents how ice loss is changing seal hunts by Yereth Rosen (9/6/2021) is non-technical summary of the paper and when an article has a rate in it we can use it in calculus:

From 2003 to 2019, the seal hunting season diminished by about a day a year, with most of that change happening at the end of the season, according to the study, published in the journal Environmental Research Letters.