Ocean acidification
climate change-induced decline of pH levels in the ocean
Ocean acidification is the ongoing decrease in the pH of the Earth's ocean. Between 1950 and 2020, the average pH of the ocean surface fell from approximately 8.15 to 8.05. Carbon dioxide emissions from human activities are the primary cause of ocean acidification, with atmospheric carbon dioxide (CO2) levels exceeding 422 ppm (as of 2024). CO2 from the atmosphere is absorbed by the oceans. This chemical reaction produces carbonic acid (H2CO3) which dissociates into a bicarbonate ion (HCO−3) and a hydrogen ion (H+). The presence of free hydrogen ions (H+) lowers the pH of the ocean, increasing acidity (this does not mean that seawater is acidic yet; It is still alkaline, with a pH higher than 8). Marine calcifying organisms, such as mollusks and corals, are especially vulnerable because they rely on calcium carbonate to build shells and skeletons.
A change in pH by 0.1 represents a 26% increase in hydrogen ion concentration in the world's oceans (the pH scale is logarithmic, so a change of one in pH units is equivalent to a tenfold change in hydrogen ion concentration). Sea-surface pH and carbonate saturation states vary depending on ocean depth and location. Colder and higher latitude waters are capable of absorbing more CO2.
This brief starts where responsible research should: with the source description of “Ocean acidification” as climate change-induced decline of pH levels in the ocean. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the places & architecture register because the source frames it as climate change-induced decline of pH levels in the ocean. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The strongest evidence will usually combine a dated visual record with documents produced by the authority responsible for the place. The source revision retrieved here is dated Sep 3, 2026. The linked authority identifier is Q855711. The Library of Congress control number is sh2010010083. None of the 1 selected statements returned an explicit reference. The first chronological checks are 1950, 2020 and 2024.
A single description cannot reconcile every naming convention, rebuilding phase or administrative transfer associated with a place. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Ocean acidification”, its source revision and the description used here.
- Expand the search: follow Ocean acidification primary sources, Ocean acidification archive and Ocean research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Ocean acidification”?
- Which authority defined the place, boundary or structure at the relevant date?
- What physical evidence or contemporary plan supports the description?
Search terms from this dossier
This entry incorporates text from “Ocean acidification” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.