Arthur purchased a tract of land for $140,000 in 2012 when he heard that a new highway was going to be constructed through the property and that the land would soon be worth $200,000. Highway engineers surveyed the property and indicated that he would probably get $180,000. The highway project was abandoned in 2016 and the value of the land fell to $100,000. What is the amount of loss Arthur can claim in 2017?