Answer:
0.1 degree per annum
Explanation:
There are 30 years between the years 2020 and 2050. If the average temperatures increase by 3 degrees Fahrenheit in 30 years, then the rate of change of temperature equals the ratio of the total increase in temperature and the number of years.
Rate of change = 3/30 = 0.1
Hence, the rate of temperature change is 0.1 degree Fahrenheit annually.
