The global carbon budget tells us how much more carbon we can emit or ‘spend’ before we risk temperatures passing 1.5°C. On the current trajectory, we have about 316 Gigatonnes left before we run out around May 2029. This is why there is such an urgent push to reduce emissions by 2030.
But this budget is based on emissions from fossil fuels and agriculture. It doesn’t include emissions from ferocious forest fires, or even more concerning, melting permafrost (Fig. 1).
“Permafrost emissions are really hard to capture in global models, so even in the [new climate models] being used to project climate in the future and the behaviour of the planet and the global climate system, these emissions are not included…climate modellers don’t want to include it; permafrost modellers really think they should.” – Video (top) State of the Cryosphere Report, COP26
“Suppose we do reach net zero emissions by 2050, permafrost is going to continue emitting for at least a couple of centuries. So, in addition to the negative emissions that are in the models to keep temperature below 1.5°C, we also have to have negative emissions to offset permafrost. And we’re going to have to continue doing that for a couple of hundred years until the permafrost stabilises,” – Op cit.
More information
- Evidence: melting permafrost & burning ice (this website; includes videos)
- The Permafrost Carbon Network
- Extensive list of peer-reviewed research and publications