Why it matters: The projected shifts in climate if greenhouse gas emissions are unmitigated show that the climate young people are growing up with today will be drastically different by the time they are older — and may even have "no modern equivalent."
By the numbers:
- In the scenarios with unchecked emissions, all 540 cities showed an increase in the average annual temperature between the current city and its contemporary analog, with an average increase of 8.2°F.
- Annual precipitation was more mixed, with 218 cities experiencing less rain and 322 with more, for an average change of +3mm.
- On average, the contemporary analog city was 528 miles from its 2080 partner.
- With lower emissions, the average distance shrinks to 230 miles, average annual temperatures would increase by 4.6°F, and precipitation would increase by 22mm.
How they did it: The study, led by Matt Fitzpatrick at the University of Maryland's Center for Environmental Sciences, used 12 temperature and precipitation variables to create 27 climate projections for each city.
- The projections are based on two underlying emissions scenarios, which were combined with Earth system models to generate 54 future climate scenarios.
- One of the emissions scenarios involves the world reining in greenhouse gas emissions, but not sufficiently to meet the Paris Climate Agreement's temperature goal.
- The other scenario, shown in the map, involves emissions continuing to increase unchecked.
The researchers took the mean of the 2080's projections for the 540 cities they examined and matched it with the contemporary city with the most similar climate.
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