Researchers at UC Santa Barbara have determined the extent to which plastic contributes to climate change, and to what it would take to curb these emissions.
In 2015 alone, the life cycle of plastics, from extraction and distillation, through to transport and disposal, emitted equivalent to 1.8 billion tonnes of CO2.
The researchers also expect this number to grow, predicting that the global demand for plastics will increase by 22 per cent over the next five years, meaning emissions will need to be cut by 18 per cent just to break even.
On the current course, emissions from plastics will reach 17 per cent of the global carbon budget by 2050, according to the results.
This budget estimates the maximum amount of greenhouse gases we can emit while still keeping global temperatures from rising more than 1.5°C.
Sangwon Suh, Professor at UC Santa Barbara’s Bren School of Environmental Science & Management, said: “This, to our best knowledge, is the first global assessment of the life cycle of greenhouse gas emissions from all plastics. It’s also the first evaluation of various strategies to reduce the emissions of plastics.”
“If we truly want to limit global mean temperature rise from the pre-industrial era below 1.5°C, there is no room for increasing greenhouse gas emissions, not to mention substantially increasing greenhouse gas emissions like what we have projected for the life cycle of plastics.”
Ultimately, the researchers found that replacing fossil-based energy with renewable sources had the greatest impact of plastic’s greenhouse gas emissions overall, as transitioning to 100 per cent renewable energy, which the researchers considered a purely theoretical scenario, would reduce emissions by 51 per cent.
Suh said: “What I’m seeing is that greenhouse gas emissions reduction will not happen unless we really make efforts at an unprecedented scale.”