Longtermists believe we need to stop AI from killing us in the next 20 years.
Short-termists believe in eradicating malaria.

As someone who hates long terms, I propose "shorty" as a short term that means short-termist (or neartermist). I like it because it does not falsely imply that short-termists don't care about the long run future. While diminutive, I think it's actually a positive term - after all, there are several traditional ballads that wax poetic about how virtuous shorties are.

See also my previous market: