Which European regions saw the biggest declines in Muslim population between 2000 and 2025 and why?
Executive summary
Available sources do not provide a single, definitive list of European regions that lost the largest Muslim populations between 2000 and 2025; national- and region-level time‑series are not supplied in the current reporting (not found in current reporting). Broadly, analysts and Pew’s reporting show that Muslim numbers in Europe rose overall from ~29.6 million in 1990 to about 44.1 million in 2010 and continued rising into the 2010s, with growth driven mainly by migration and higher fertility, even as some countries’ populations would have declined without immigration [1] [2] [3].
1. "No continent‑wide collapse — overall Muslim numbers rose, not fell"
Pew’s regional assessments and subsequent summaries show Europe’s Muslim population increased between 1990 and 2010 and was projected to keep growing through the 2010s and 2020s; the sources emphasize growth driven by migration and higher fertility among Muslims compared with non‑Muslims [1] [2]. Statista/Pew charts cited by commentators likewise present scenarios of increase to mid‑century rather than continent‑wide decline [4] [5].
2. "Why you won’t find clear data on 2000–2025 declines: migration, fertility and classification problems"
Available sources note three reasons national or regional declines are hard to pin down in this period: migration is the dominant short‑term driver and varies year‑to‑year and by country, complicating simple before‑and‑after counts [1] [3]; fertility differences — Muslim women averaged higher TFRs in the datasets used — make natural decrease less likely absent net emigration [1] [2]; and data gaps and definitional issues (religion recorded inconsistently across censuses) mean many analyses rely on projections and scenarios rather than complete counts [6] [4].
3. "Where declines are plausible — smaller countries and post‑Soviet spaces"
While the sources do not list regions with confirmed declines 2000–2025, they imply places most at risk of local declines are those where Muslim populations are small and highly migration‑dependent: small EU states and some parts of Central and Eastern Europe where historical indigenous Muslim communities exist but migration flows diminished. Pew’s work highlights that migration flows to some traditional destination countries were projected to fall in the mid‑2020s compared with 2010–2015, which could reduce Muslim inflows and, combined with aging, produce local shrinkage [1]. The Europarliament report also discusses demographic shifts in Eastern Europe and the possibility of stabilising or limited Muslim populations in certain scenarios [7].
4. "Drivers that would cause declines, if present"
Sources identify three clear mechanisms that would reduce a Muslim population in a region: sustained net emigration or reduced immigration (Pew projects fewer Muslim immigrants to some countries in 2025–2030 than 2010–2015) [1]; falling fertility that narrows the historical Muslim/non‑Muslim fertility gap (Pew projects Muslim TFR in Europe to fall toward 2.0 by 2025–30) [1]; and aging and higher mortality as a Muslim community’s median age rises [2] [1]. Any combination could produce local declines even while continental totals remained flat or rising.
5. "Competing interpretations and political uses of the numbers"
Commentators and watchdogs stress caution: some publications claim dramatic “Islamization” scenarios based on high‑migration projections, while fact‑checkers and academic pieces argue even high‑migration models show Muslims remaining a minority and that modest percentage changes do not equal takeover [8] [9] [5]. The European Parliament briefing and Pew highlight that assumptions about fertility and migration critically shape projections; political actors may selectively cite the most alarmist scenarios [7] [1].
6. "What solid reporting could still supply — and what is missing"
Pew and related analyses offer regional projections and fertility/migration context but do not provide a tidy list of European regions that demonstrably lost Muslim population between 2000 and 2025 (not found in current reporting). To answer your original question definitively, we would need consistent subnational censuses or a harmonized time series for 2000–2025 showing country or regional Muslim counts and net migration flows; current sources instead provide trends, scenarios and drivers [1] [4].
7. "Bottom line for readers"
Available evidence shows Europe’s Muslim population rose overall into the 2010s and early 2020s, with migration and higher fertility as main engines; projections and scenario work, and explicit caveats from Pew and EU analyses, indicate that regional declines are possible only where immigration falls and fertility/age structure change unfavorably — but the sources do not identify a definitive list of regions that experienced the biggest declines between 2000 and 2025 [3] [1] [7].