Committed future carbon dioxide (CO2) emissions from existing and proposed energy infrastructure already exceed what can be emitted if global warming is to be limited to 1.5 degrees Celsius, according to international researchers.
And they would eat up around two-thirds of the remaining carbon budget even if we only aim for a limit of 2 degrees Celsius, they add.
A team led by Dan Tong from the University of California, Irvine, US, examined future emissions across electricity generation, industry, transport, residential, commercial and other energy infrastructure.
They found that if all the proposed power plants are built, and energy infrastructure continues to operate as it has done historically, their emissions will total around 846 billion tonnes.
If we’re not happy with that, the most obvious infrastructure to consider retiring early, they say, is in the electricity and industry sectors, which make up 75% of emissions but less than 25% of economic value. {%recommended 9322%}
Writing in the journal Nature, Tong and colleagues note that recent decades have witnessed an unprecedented expansion of historically long-lived fossil fuel energy infrastructure, particularly associated with rapid economic development and industrialisation of emerging markets such as China and India, along with a shift towards natural gas-fired power plants in the US.
“Although such expansion may be slowing, substantial new electricity generating capacity is proposed – and in many cases already under construction,” they write.
“Consequently, there is a tension between dwindling carbon emissions budgets and future CO2 emissions locked-in or ‘committed’ by existing and proposed energy infrastructure.”
For their study, the researchers used datasets on existing and proposed – that is, planned, permitted or under construction – fossil-fuel-burning energy infrastructure as of the end of 2018.
They present region- and sector-specific estimates of future emissions, as well as the sensitivity of such estimates to assumed lifetime and utilisation rates, and the economic value of associated energy assets.
“Detailed and up-to-date analysis of existing and proposed CO2-emitting energy infrastructure worldwide reveals incredibly tight constraints of current international climate targets even if no new emitting-infrastructure is ever built,” they write.
“Although climate and energy analysts have emphasised that avoiding 1.5°C of warming, for example, remains ‘technically possible’, our results lend vivid context to that possibility.
“We would have a reasonable chance of achieving the 1.5°C target with (1) a global prohibition of all new CO2-emitting devices, including many or most of the already proposed fossil fuel-burning power plants, and (2) substantial reductions in the historical lifetimes and/or utilisation rates of already existing industry and electricity infrastructure.
“Barring such radical changes, the global climate goals adopted in the Paris Agreement are already in jeopardy and may be contingent upon widespread retrofitting of existing emitting infrastructure with carbon capture and storage technologies (which retrofits would be tremendously expensive), large-scale deployment of negative emissions technologies, and/or solar radiation management.
“On the other hand, our results suggest that the level of future warming in excess of the Paris targets is largely dependent on infrastructure that has not been built yet.”