Climate change gets blamed for a lot of things these days: inundating small islands, fueling catastrophic fires, amping-up hurricanes and smashing Arctic sea ice.

But a global review of insect research has found another casualty: 40% of insect species are declining and a third are endangered. It confirms what many have been suspecting: in Australia and around the world, arthropods – which include insects, spiders, centipedes and the like — appear to be in trouble.

The global review comes hard on the heels of research published in the Proceedings of the National Academy of Sciences USA that suggests a potent link between intensifying heat waves and stunning declines in the abundance of arthropods.https://theconversation.com/climate-change-is-killing-off-earths-little-creature...

The main drivers of species declines appear to be in order of importance: i) habitat loss and conversion to intensive agriculture and urbanisation; ii) pollution, mainly that by synthetic pesticides and fertilisers; iii) biological factors, including pathogens and introduced species; and iv) climate change. The latter factor is particularly important in tropical regions, but only affects a minority of species in colder climes and mountain settings of temperate zones.

A small rodent that lived only on a single island off Australia is likely the world's first mammal to become a casualty of climate change, scientists reported in June 2016. The government of Australia has now officially recognized the Bramble Cay melomys (Melomys rubicola) as extinct.

The animal seems to have disappeared from its home in the eastern Torres Strait of the Great Barrier Reef, scientists say. The animal was last seen by a fisherman in 2009, but failed attempts to trap any in late 2014 prompted scientists to say it is likely extinct.

Also called the mosaic-tailed rat, the rodent is named after its home on Bramble Cay, a small island that is at most 10 feet above sea level.

The rats were first seen by Europeans on the island in 1845, and there were several hundred there as of 1978. But since 1998, the part of the island that sits above high tide has shrunk from 9.8 acres to 6.2 acres. That means the island's vegetation has been shrinking, and the rodents have lost about 97 percent of their habitat.

"The key factor responsible for the extirpation of this population was almost certainly ocean inundation of the low-lying land, very likely on multiple occasions, during the last decade, causing dramatic habitat loss and perhaps also direct mortality of individuals," writes the team, led by Ian Gynther from Queensland’s Department of Environment and Heritage Protection.

“For low-lying islands like Bramble Cay, the destructive effects of extreme water levels resulting from severe meteorological events are compounded by the impacts from anthropogenic climate change-driven sea-level rise,” the authors add.

Now, a new set of long-term data is coming to light, this time from a dedicated group of mostly amateur entomologists who have tracked insect abundance at more than 100 nature reserves in western Europe since the 1980s.

Over that time the group, the Krefeld Entomological Society, has seen the yearly insect catches fluctuate, as expected. But in 2013 they spotted something alarming. When they returned to one of their earliest trapping sites from 1989, the total mass of their catch had fallen by nearly 80% (see graph, right). Perhaps it was a particularly bad year, they thought, so they set up the traps again in 2014. The numbers were just as low. Through more direct comparisons, the group—whichhad preserved thousands of samples over 3  decades—found dramatic declines across more than a dozen other sites.

Such losses reverberate up the food chain. “If you’re an insect-eating bird living in that area, four-fifths of your food is gone in the last quarter-century, which is staggering,” says Dave Goulson, an ecologist at the University of Sussex in the United Kingdom, who is working with the Krefeld group to analyze and publish some of the data. “One almost hopes that it’s not representative—that it’s some strange artifact.”

No one knows how broadly representative the data are of trends elsewhere. But the specificity of the observations offers a unique window into the state of some of the
planet’s less appreciated species. Germany’s “Red List” of endangered insects doesn’t look alarming at first glance, says Sorg, who curates the Krefeld society’s extensive collection of insect specimens. Few species are listed as extinct because they are still found in one or two sites. But that obscures the fact that many have disappeared from large areas where they were once common.

Across Germany, only three bumble bee species have vanished, but the Krefeld region has lost more than half the two dozen bumble bee species that society members documented early in the 20th century