I came to a counterintuitive conclusion on this one. Wondering who else will.

@Lexer I'm with you. 2023 was an outlier. I don't follow climate change news closely, but we had a bunch of weirdness with polar vortices or something. So, without making a more detailed model I have to expect some amount of regression to the mean.

From the NOAA dataset, which is being used for resolution.

Though rolling averages are obviously increasing fast, I'm investing in NO because the likelihood of a positive YoY change is surprisingly low. Plus, 2023 represents a huge YoY spike, making a reversion to the mean in 2024 likely.

https://www.metoffice.gov.uk/about-us/press-office/news/weather-and-climate/2024/met-office-carbon-dioxide-forecast-on-the-limits-of-compatibility-for-achieving-1.5c The build-up of atmospheric carbon-dioxide between 2023 and 2024 is forecast to be faster than that required to track IPCC scenarios that limit global warming to 1.5°C, that is the finding from the latest Met Office CO₂ forecast.

Which dataset (e.g. NASA, NOAA, Berkeley Earth)? How are ties resolved?

@StevenK I‘d say NOAA is a good dataset

@StevenK If there is a tie, I return 50%

Two words: El Niño

@Gideon37 But might have peaked in December

Why close so early?

@ICRainbow Changed it

The trend is your friend!