Ice cream melts faster than it used to.
In 2016, the average global temperature, according to the NASA Goddard Institute for Space Sciences (GISS) data analysis, was the warmest on record, besting the previous mark which was set in 2015. Earth has something of a streak going -- the last three full calendar years have cumulatively been the three warmest years on record.
There is unambiguous evidence that climate change, driven by increasing atmospheric CO2 concentration (as well as other greenhouse gases), is responsible for the relentless upward trend. Nonetheless, stochastic variations do lend a short-term veneer of unpredictability to near-term measurements.
A recently closed Metaculus question that asked whether 2018 will break the global heat record was quite popular -- 458 predictions were registered, with the community of predictors ascribing a median 33% chance of going over the top. Given the interest, it seems reasonable to roll the question out for the coming year:
Will 2019 again set a new record? Or will it fall off the recent record-setting pace?
This will resolve in the positive if the NASA GISS global average temperature for 2019 is published above that of any prior year for which records exist. As a practical matter, this will be either 2016 or (possibly) 2018.