Table schema:
CREATE TABLE table_2508175_1 (country VARCHAR, annual_co2_emissions__in_thousands_of_metric_tons_ VARCHAR)

Question: when the annual co2 emissions (in thousands of metric tons) is 1811, what is the country?
SQL: SELECT country FROM table_2508175_1 WHERE annual_co2_emissions__in_thousands_of_metric_tons_ = 1811