Last month was the first June on record when the daily average global 2-metre surface temperature exceeded 1.5 °C above pre-industrial levels [1] and last week, on July 6th, the daily global air temperature hit a record high of 17.23 °C [2]  In 2020 it was estimated that the world’s remaining carbon budget was about 500 gigatonnes CO2 if there was to be a 50% chance of limiting global warming to 1.5 °C. It is now estimated that the remaining budget is about 250 gigatonnes CO2, i.e., it has halved in three years, as a result of continued pollution and temperatures rising faster than expected [3].  At the current rate of emissions, this budget will be exhausted in about six years.  Hence, it seems very likely that global temperatures will rise by more than 1.5 °C and perhaps by as much as 4 °C this century.  The last time the Earth was that hot was about 15 million years ago during the Miocene when sea levels were 40 m higher [4].  It is time to get much more serious about reducing carbon emissions instead of just talking about it.  Current targets for reducing emissions are so far in the future that they are beyond the horizon – effectively out of sight and out of mind.  We need to be costing everything in terms of carbon emissions and making decisions that reduce emissions now.

[1] Climate graphic of the week: first days of June bring record heat, FT June 17, 2023.

[2] Global temperature hits record high, FT Weekend 8th July 2023 based on data from NOAA.

[3] Forster PM, Smith CJ, Walsh T, Lamb WF, Lamboll R, Hauser M, Ribes A, Rosen D, Gillett N, Palmer MD, Rogelj J. Indicators of Global Climate Change 2022: annual update of large-scale indicators of the state of the climate system and human influence. Earth System Science Data. 15(6):2295-327, 2023.

[4] Foster GL, Rohling EJ. Relationship between sea level and climate forcing by CO2 on geological timescales. Proceedings of the National Academy of Sciences. 110(4):1209-14, 2013.