Wiping out all of Africa’s elephants could accelerate Earth’s climate crisis by allowing 7% more damaging greenhouse gases into the atmosphere, scientists say. But conserving forest elephants may reverse the trend, providing a service worth $43billion in storing carbon, the academics found. The research, published in Nature Geoscience, shows that the presence of the animals leads to higher numbers of large trees that better capture greenhouse gas, but without elephants, smaller trees less able to absorb carbon thrive. The extinction of forest elephants could lead to a 7% drop in “aboveground biomass” — living vegetation including stems, branches, seeds and foliage — in western and central African rainforests. Large herbivores are known to be vital in spreading seeds, but until now ways in which elephants affect rainforests have been something of a mystery. But the study found that while grazing in the Congo and elsewhere, the animals clear away smaller vegetation, which over time leads to fewer but larger trees, which are denser and lock away more carbon. Earlier this month, Swiss scientists reported that planting billions of acres of trees in an area the size of the US could be the “most effective solution to climate change to date”. Using model simulations, the scientists from the Laboratory of Climate and Environment Sciences in France said one animal for every square km increases forest biomass by 60 tonnes per hectare. Fabio Berzaghi and his colleagues found that when elephants thin out forests, eating those that are less than 30cm wide, there is less competition among the vegetation for light, water and space, which allows fewer and larger trees — and with a higher wood density — to emerge, increasing amounts of carbon stored. The total canopy cover was about 70% more in areas with elephants than those without, so only about half the natural light reached the ground, inhibiting growth of small trees. The research suggests elephants have an important role in shaping the structure of African forests. “We speculate that the presence of forest elephants may have shaped the structure of Africa’s rainforests, which probably plays an important role in differentiating them from Amazonian rainforests,” the paper said