Stopping global warming at 1.5°C can save a vast number of species

The effects of global warming are projected to influence climate across the entirety of our planet, changing ecosystems and weather patterns along the way. These changes put many plant and animal species in jeopardy, as they need to adapt more quickly to a less hospitable environment. Now, a new study published in Science has found that limiting global warming to 1.5°C would save the vast majority of the planet’s animal and plant species from climate change.

While past research has focused on quantifying the benefits of limiting warming to 2°C above pre-industrial times, they have not explored how this affects insects. This new research from the University of East Anglia (UEA) is the first to explore how limiting warming to 1.5°C would benefit species globally.

Researchers from UEA and James Cook University in Australia assessed roughly 115,000 species – including 31,000 insects, 8,000 birds, 1,700 mammals, 1,800 reptiles, 1,000 amphibians, and 71,000 plants. Not surprisingly, this is the largest scale study of its kind.

The research team was looking at how different projected climate futures affected areas, making them climatically unsuitable for the plants and animals that live there. “We measured the risks to biodiversity by counting the number of species projected to lose more than half their geographic range due to climate change,” explains Rachel Warren, a professor at UEA and lead researcher on the study. “We found that achieving the ultimate goal of the Paris Agreement, to limit warming to 1.5°C above pre-industrial levels, would reap enormous benefits for biodiversity – much more so than limiting warming to 2°C.”

Their results showed that insects were especially sensitive to climate change. Of the 31,000 insects studied, 18 percent were projected to lose over half their range at a 2°C increase. But at a 1.5°C increase, the number was reduced to 6 percent.

“The current global warming trajectory, if countries meet their international pledges to reduce CO2, is around 3°C,” says Warren. “In this case, almost 50 percent of insects would lose half their range. This is really important because insects are vital to ecosystems and for humans. They pollinate crops and flowers, they provide food for higher-level organisms, they break down detritus, they maintain a balance in ecosystems by eating the leaves of plants, and they help recycle nutrients in the soil.”

Even more concerning, the researchers found that the three biggest groups of pollinating insects were the most sensitive to warming.

In their study, the researchers also assessed the ability of species to relocate to more habitable locations as the climate changes. “If warming is limited to 1.5°C by 2100 then more species can keep up or even gain in range, whereas if warming reached 2°C by 2100 many species cannot keep up and far more species lose large parts of their range,” Warren says.

Although just half-a-degree Celsius may not seem like much, this study shows that there are major consequences that lie between 1.5 and 2°C. If we aren’t able to cut back on the contributing factors to man-made climate change, we might be finding out what those consequences are for ourselves.

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By Connor Ertz, Earth.com Staff Writer