CREATE TABLE table_29538735_1 (year VARCHAR2, tonnes_of_co2_saved VARCHAR2)

When 1522 is the tonnes of co2 saved what is the year?
SELECT year FROM table_29538735_1 WHERE tonnes_of_co2_saved = 1522
SELECT "year" FROM "table_29538735_1" WHERE "tonnes_of_co2_saved" = 1522