Limiting temperatures to +2°C still possible but any delay increases cost and climate risks

To achieve the Paris Agreement aims, and limit global warming to well below +2°C, or ideally below +1.5°C, many governments are aiming to reduce emissions to net zero by 2050. However, with ongoing high emissions since 2015, the window for limiting climate change has narrowed considerably.

Each year of delay shrinks the remaining carbon budget, necessitating a much faster timeline for reaching net zero. We estimate net zero now needs to be achieved by 2034 to limit the global warming increase to +1.5°C by 2100.

Based on progress since 2015, it seems unlikely that net zero will be achievable by 2034. Therefore, if the +1.5°C target is retained, large-scale removals of CO2 from the atmosphere will be needed.

For example, if net zero anthropogenic emissions could be guaranteed globally by 2050 (the current trajectory suggests net zero is beyond 2060) then ~500 bn tCO2 would need to be removed from the atmosphere to limit temperatures to +1.5°C.

Reforestation could provide up to ~40% of atmospheric removals, assuming high productivity of all reforested land and no losses through wildfires, future development or climate impacts (e.g. drought) or use as plantations. However, this would require the planting of ~38 billion trees per year from today. This compares to a current global deforestation rate of ~2.5 billion trees per year.

The rest of the atmospheric removals would need to come from largely unproven technological solutions, such as direct air capture (DAC), and amount to a capacity requirement of ~27 bn tCO2/y by 2050, which we estimate would require an investment of >$50 tn (real 2023) and consume ~1.1 bn t of steel with a power demand of >13,000 TWh/y, ~50% of current global demand, by 2050.

Each year of high emissions makes achieving the ambitious +1.5°C target increasingly difficult and puts it likely out of reach. However, meeting a +2°C target still seems possible but without faster reduction in emissions as well as increased reforestation and a stronger focus on atmospheric removals, even this target could fall by the wayside.

Earlier action brings lower costs, a smoother transition and less reliance on unproven technologies, thus increasing our chances of avoiding climate catastrophe.

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About The Author

Paul Butterworth , Research Manager

Paul moved to CRU's newly-formed Sustainability team in August 2021 where he is working closely with clients and internally on carbon market and energy transition issues. Paul joined CRU in 2012 and, latterly, was responsible for CRU's analysis across the whole steel value chain.