In 2021, President Biden announced a strengthened domestic emission reduction target of 50-52% below 2005 levels by 2030, including land-use, land-use change and forestry (LULUCF), which translates to 3.7-4.2 GtCO₂e/yr by 2030, or 43-50% below 2005 levels, excluding LULUCF.
This updated domestic target falls short of 1.5°C compatibility, which would require the US to target emissions reductions of 60% (55-66%) below 2005 levels, resulting in emissions of 2.9 (2.5-3.3) GtCO₂e/yr by 2030, excluding LULUCF emissions.
A fair share contribution to reduce global greenhouse gas emissions compatible with the Paris Agreement would require the US to go further than its domestic target, and provide substantial support for emission reductions to developing countries. The US’ fair share (domestic and international support) would require the country to finance or provide support for mitigation abroad equivalent to domestic emissions reductions of at least 75% below 2005 levels by 2030 when excluding LULUCF on top of its domestic reductions.
President Biden has announced plans to reach net zero emissions by 2050. This would mean the US’ remaining emissions in 2050 would need to be within a range of 0.8 GtCO₂e/yr, or a reduction of 90-96% below 2005 levels excluding land sinks, but including the use of BECCS.,
The US would need to balance the remaining emissions through the use of carbon dioxide removal (CDR) approaches. Our analysis shows that, assuming LULUCF sinks remain at current levels, net zero GHGs could be achieved by 2057, and net zero CO₂ by 2052.
Achievement of net zero CO₂ before mid-century requires rapid decarbonisation in the power sector, as this is a catalyst for decarbonisation of other sectors. Reductions in the transport and industry sectors would also need to be prioritised as they are significant contributors to US emissions.