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El Niño and a record CO2 rise

The recent El Niño event has elevated the rise in CO2 concentration this year. Here, using emissions, sea surface temperature data and a climate model, we forecast that the CO2 concentration at Mauna Loa will for the first time remain above 400 ppm all year, and hence for our lifetimes.

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Figure 1: Identifying, testing and forecasting the relationship between Niño 3.4 SST anomalies and Mauna Loa CO2 growth rates.
Figure 2: CO2 growth rate (minus anthropogenic emissions component) versus Niño 3.4 anomaly9.
Figure 3: Observed and forecast CO2 concentrations at Mauna Loa.


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We thank C. MacLachlan for performing the GloSea5 simulations, N. Rayner for providing the HadSST data, and S. Ineson and A. Scaife for comments. R.A.B received support from the European Commission's 7th Framework Programme (EU/FP7) under Grant Agreement 603864 (HELIX). The work of R.A.B., C.D.J., J.R.K. and J.J.K. forms part of the DECC/Defra Met Office Hadley Centre Climate Programme GA01101. R.F.K. was supported by the US Department of Energy under award DE-SC0012167 and by Schmidt Philanthropies.

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Betts, R., Jones, C., Knight, J. et al. El Niño and a record CO2 rise. Nature Clim Change 6, 806–810 (2016).

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