One way to look at how problematic this is would be to think in terms of a carbon budget. We can estimate how much carbon can be put into the atmosphere before warming reaches 1.5° C. Subtract the emissions we've already added, and you get the remaining budget. At this point, the remaining budget for 1.5° C is only 200 Gigatonnes, which means another four years like 2023 will leave us well beyond our budget. For the 2° C budget, we've got less than 20 years like 2023 before we go past.
An alternate way to look at the challenge is to consider the emissions reductions that would get us on track. UNEP uses 2019 emissions as a baseline (about 52 Gigatonnes) and determined that, in 2030, we'd need to have emissions cut by 28 percent to get onto the 2° C target, and by 42 percent to be on track for the 1.5° C target.
The NDCs are nowhere close to that, with even the conditional pledges being sufficient to only cut emissions by 10 percent. Ideally, that should be prompting participating nations to be rapidly updating their NDCs to get them better aligned with our stated goals. And, while 90 percent have done so since the signing of the Paris Agreement, only a single country has made updated pledges over the past year.
Countries are also failing to keep their national policies in line with their NDCs. The UNEP report estimates that current policies allow the world collectively to emit two Gigatonnes more than their pledges would see being released.
A limited number of countries are responsible for the huge gap between where we need to go and what we're actually doing. Nearly two-thirds of 2023's emissions come from just six countries: China, the US, India, the EU, Russia, and Brazil. By contrast, the 55 nations of the African Union are only producing about 6 percent of the global emissions. Obviously, this means that any actions taken by these six entities will have a disproportionate effect on future emissions. The good news is that at least two of those, the EU and US, saw emissions drop over the year prior (by 7.5 percent in the EU, and 1.4 percent in the US), while Brazil remained largely unchanged.