Dam(n) Beavers.....
probably more a part of the successional transformation of habitats caused by climate change than "agents of destruction", but an interesting read nonetheless.
Beavers Emerge as Agents of Arctic Destruction
Even as climate change shrinks some populations of arctic animals like polar bears and caribou, beavers may be taking advantage of warming temperatures to expand their range. But as the beavers head north, their very presence may worsen the effects of climate change.
The issue isnt just that the beavers are moving into a new environment its that theyre gentrifying it.
Take the dams they build on rivers and streams to slow the flow of water and create the pools in which they construct their dens. In other habitats, where the dams help filter pollutants from water and mitigate the effects of droughts and floods, they are generally seen as a net benefit. But in the tundra, the vast treeless region in the Far North, beaver behavior creates new water channels that can thaw the permanently frozen ground, or permafrost.
When you start flooding areas with permafrost you immediately trigger permafrost degradation, said Ken Tape, an assistant professor at the University of Alaska in Fairbanks who has researched the beavers. You start thawing the frozen ground thats holding the soil together, and that water and soil and other things are washed away.
https://www.nytimes.com/2017/12/20/climate/arctic-beavers-alaska.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=second-column-region®ion=top-news&WT.nav=top-news