Rapid Permafrost Collapse
Arctic permafrost can thaw so quickly that it triggers landslides, drowns forests and opens gaping sinkholes. This rapid melt, described in a new study, can dramatically reshape the Arctic landscape in just a few months.
Fast-melting permafrost is also more widespread than once thought. About 20% of the Arctic’s permafrost — a blend of frozen sand, soil and rocks — also has a high volume of ground ice, making it vulnerable to rapid thawing. When the ice that binds the rocky material melts away, it leaves behind a marshy, eroded land surface known as thermokarst.
Frozen water takes up more space than liquid water, so when ice-rich permafrost thaws rapidly — “due to climate change or wildfire or other disturbance” — it transforms a formerly frozen Arctic ecosystem into a flooded, “soupy mess,” prone to floods and soil collapse. This can happen very quickly, causing relatively dry and solid ecosystems (such as forests) to turn into lakes in the matter of months to years.
Global warming is literally dissolving the ocean’s plankton
Ocean acidification is wreaking havoc on the ocean’s tiniest inhabitants, and the entire ocean is likely feeling the effects.
Many of the ocean’s inhabitants have soft bodies protected by hard shells. Clams, oysters, and sea snails have them, as do multiple other types of mollusks and plankton. These seashells are almost always made of calcium carbonate — which, under most conditions, is fine. The ocean water is well-suited to support calcium carbonate under normal conditions.
Seawater is slightly basic (meaning pH > 7). When we increase the amount of carbon dioxide (CO2) we emit, not all of it goes into the atmosphere. Much of it, in fact, is absorbed by the oceans. As oceans absorb CO2, their chemistry starts to change, and they become more acidic.
Lyndsey Fox, a researcher from Kingston University in London, analyzed plankton fossils gathered by the 1872–76 expedition of the HMS Challenger and compared them to plankton gathered from a 2011 expedition to the eastern equatorial Pacific Ocean called Tara.
All modern plankton had much thinner shells — up to 76% thinner. In some cases, the shells were so thin that the team wasn’t even able to image them. Plankton is at the foundation of the ocean food chain and if it were to collapse, life in the oceans would probably be unable to recover.