Climate change, pollution and habitat destruction are raising the risk of extinction for a fifth of the world’s invertebrates, scientists say. Invertebrates make up nearly 80 percent of the world’s species, and such a significant loss would have lasting repercussions across the globe.

A new study by the Zoological Society of London and the International Union for Conservation of Nature found that human impacts contributing to the rising pH levels of the oceans, also known as ocean acidification, and increasing amounts of carbon dioxide in the atmosphere could be particularly harmful for species with external skeletons that can erode. Other problems affecting invertebrates include agricultural runoff, habitat loss and industrial waste.

The report assessed 12,000 species in the IUCN’s Red List of endangered species. However, the list only covers 1 percent of all described marine invertebrate species and even fewer (0.3 percent) of all described land invertebrates, so the threat could be significantly higher than the study determined.

These invertebrates are particularly helpful to humans in that many of them are insects that pollinate flowers or marine animals that help with water filtration, scientists say.

Spineless creatures have been largely ignored by human conservation efforts, scientists say. Conservation spending has historically focused on more iconic species such as eagles and polar bears. But this study proves that smaller, more prolific invertebrates like jellyfish and butterflies are just as vulnerable to pollution and our warming climate.

The report includes calculated worths of some of the potentially threatened invertebrates identified by the report. For example, the estimated worth of honeybees to the British economy was £200 million in 2007. Many people do not think about how integral insects and other invertebrates are to the economy, but their existence is worth billions of dollars each year across the globe.

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