About 8.4 billion tonnes of carbon is estimated to have been accumulated and stored in long-lasting products from around the world made by humans, such as plastics and buildings, between 1995 and 2019, according to a study. Researchers at the University of Groningen in the Netherlands said this 'fossil carbon' added to the 'technosphere' -- the sum of all human-made objects, both in use and discarded -- equals around 93 per cent of carbon dioxide emissions from around the world in 2019. They added that the carbon locked up in the 'technosphere' has a huge potential to add to greenhouse gas emissions. Increasing the lifetime of products and recycling rates are two ways to reduce the amount of fossil carbon entering waste streams, the researchers suggested. "Over these 25 years (1995-2019), 8.4 billion tons of fossil carbon have accumulated, with approximately 0.4 billion tons added each year, with a huge potential for further contribution to anthropogenic greenhouse gas emissions,"