Research date: 17 October 2026 Topic choice Question: what happened to the acid-rain problem many readers remember? Finding: a large drop in sulfur dioxide accompanied almost unchanged electricity generation in EPA's covered-plant comparison. The result is easy to see with two directly labeled lines sharing a single index axis. It offers a concrete environmental improvement with a meaningful remaining limitation: ecosystem recovery is uneven. Interest evidence, not a prediction A July 15, 2026 r/askscience question about what happened to acid rain showed roughly 1,593 votes, with its leading explanation around 8,319 votes when reviewed. https://www.reddit.com/r/askscience/comments/1uwtt8g/what_happened_with_the_acid_rain_scare_of_the/ This suggests recognizable curiosity about the question, but a different subreddit's votes cannot predict a DataIsBeautiful result. An older May 1, 2019 DataIsBeautiful acid-rain visualization showed only about 18 votes. https://www.reddit.com/r/dataisbeautiful/comments/bjiupq/ That is weak evidence for chart-specific appeal, and the topic itself is not new. The new work is an original visualization and analysis of this explicit source window. Search was limited and does not establish that no similar chart exists. Recent environmental examples A September 18, 2026 greenhouse-gas-by-country post showed about 9,785 votes. https://www.reddit.com/r/dataisbeautiful/comments/1wjnkm3/oc_greenhouse_gas_emissions_by_country_2025/ A September 25, 2026 plastic-waste post showed about 556 votes, with comments challenging global generalizations and disposal definitions. https://www.reddit.com/r/dataisbeautiful/comments/1wprr8v/oc_what_actually_happens_to_our_plastic_waste/ An October 12, 2026 solar-growth post already covered the current global electricity result, so that was less attractive as this attempt. https://www.reddit.com/r/dataisbeautiful/comments/1x4ejjl/oc_solar_supplied_76_of_the_increase_in_global/ Practical lessons: make the main comparison immediately readable, name the geographic and program scope, and keep different environmental measures distinct. Assessment: moderately promising as an accessible historical explanation, with no reliable basis for promising high engagement. Main weakness: a historical window through 2023 supplies less immediate news relevance than a current-event topic. Primary sources 1. EPA Emissions Reductions, through 2023. https://www.epa.gov/power-sector/progress-report-emissions-reductions Use Figure 4's fuel-specific SO2 emissions and generation series embedded in the published HTML. The headline uses sums of those exact arrays, rather than the rounded percentages elsewhere on the page. Figure 4 sums differ slightly from EPA's separately published overall emissions totals, so do not silently substitute the latter. The snapshot retains the eight numeric arrays, years, URL, retrieval time, and source HTML SHA-256. 2. EPA Program Basics and Acid Rain Program. https://www.epa.gov/power-sector/progress-report-program-basics https://www.epa.gov/acidrain/acid-rain-program Programs cover large fossil-fuel electricity generating units; the source's historical membership varies. Phase II of the Acid Rain Program began in 2000, which also starts the matching annual fuel-series comparison. CSAPR-only SO2 units enter in 2015. The chart does not estimate the causal contribution of a particular rule. 3. EPA Atmospheric Deposition, through 2022. https://www.epa.gov/power-sector/progress-report-atmospheric-deposition Reported eastern-U.S. wet sulfate deposition reduction: 73%, comparing the 2000 to 2002 and 2020 to 2022 averages. This separate outcome has its own region, period and units; it is not rainfall acidity or the 94% emissions statistic. 4. EPA Ecosystem Response, through 2022. https://www.epa.gov/power-sector/progress-report-ecosystem-response The source documents slower and mixed recovery in central Appalachian streams. Avoid saying acid rain has been eliminated or all damage has healed. Arithmetic 2000 SO2: 11,201,497 short tons. 2023 SO2: 650,359 short tons. Reduction: 94.1939992484933%, displayed as 94%. 2000 generation: 2,476,377,084 MWh. 2023 generation: 2,430,428,806 MWh. Change: -1.8554637053005418%, displayed as -2%. TWh conversion: MWh / 1,000,000. Each index: annual value / its own 2000 value * 100. All 24 years are included; no smoothing or interpolation is applied. Submission preparation The visible subreddit rules were reviewed on 17 October 2026. https://www.reddit.com/r/dataisbeautiful/wiki/rules/ The sidebar requires a qualifying visualization, a descriptive title, an OC tag for original work, and data sources and tools in the first top-level comment. The rain photograph's generated origin is disclosed in the alternate's source/tools comment and artwork credits. The U.S.-politics Thursday restriction is relevant if the post is framed as a U.S. political argument; the draft stays with the historical measurements. No submission, comment, or other Reddit interaction was performed.