There may now be more buildings than trees and more plastic than animals, in terms of mass, as humans are creating things faster than nature can produce living biomass.
Ron Milo and his colleagues at Weizmann Institute of Science in Israel have estimated the mass of all artificial and living things on the planet. They say that 2020 may be the year in which humanity鈥檚 creations outweigh the biosphere.
鈥淲e are really at the cusp of the transition where around us are more human-made things than living things,鈥� says Milo.
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The team says that in 1900, the mass of human-made objects was only 3 per cent of the total mass of all living things, referred to as biomass. Now, the mass of artificial objects is on course to be triple that of living biomass by 2040.
Most of the human-made mass is in infrastructure, such as buildings and roads, whereas trees and shrubs make up 90 per cent of living biomass. The team estimates there are 1100 gigatonnes of buildings and 8 Gt of plastic on the planet, compared with 900 Gt of trees and 4 Gt of animals, including humans.
The researchers say the total mass of living things on Earth has remained roughly the same since 1900, while the mass of human-made objects has doubled around every 20 years. It is impossible to say exactly when artificial mass overtook or will overtake biomass, but the team says it is probably between 2014 and 2026.
The biggest surge of artificial objects occurred following the second world war during a period of increased consumption and urban development known as the 鈥済reat acceleration鈥�, the team says.
鈥淭he work opens up more questions than provides answers, but those questions are fascinating, not least what might be the limits to the growth in rate of accumulation of infrastructural mass and what implications does it have for disposal,鈥� says Jeremy Woods at Imperial College London. 鈥淭his serves to strongly underline the need for wise and informed human stewardship of the environment.鈥�
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