Here is the full list of all 33 Defiance 2050 achievements worth 1,000 gamerscore.
Complete 4 weekly contracts
Complete 10 major arkfalls in the Bay Area
Equip your first legendary weapon
Complete 20 pursuits in the Bay Area
Complete any daily contract
Kill Nim
Get to EGO level 50
Complete any co-op map
Cross the Golden Gate Bridge
Complete 10 pursuits in the Bay Area
Fully upgrade an ability
Jump a total of 5 kilometers with vehicles
Max out a class
Revive another player outside the tutorial
Get to EGO level 10
Complete your first pursuit in the Bay Area
Complete your first major arkfall in the Bay Area
Complete your first minor arkfall in the Bay Area
Complete the tutorial
Complete all other achievements
Complete all co-op maps
Max out reputation with 1 faction
Max out reputation with 4 factions
Earn 50 perks
Reach level 20 in any weapon skill
Kill 10,000 enemies
Capture 50 points in PvP
Kill 100 players in PVP
Complete the "Thorn Liro Thawandaye II" pursuit
Kill the Volge Warmaster and a Volge Huntmaster
Complete 25 sieges
Complete the "The Defiant Few II" pursuit
Complete "The Lion's Claw II" pursuit