Category:20th century in the environment 15th16th17th18th19th20th21st22nd23rd24th25th Subcategories This category has the following 19 subcategories, out of 19 total. 0–9 1900s in the environment (17 C) 1910s in the environment (16 C) 1920s in the environment (16 C) 1930s in the environment (16 C) 1940s in the environment (17 C) 1950s in the environment (17 C, 1 P) 1960s in the environment (16 C) 1970s in the environment (16 C, 2 P) 1980s in the environment (17 C) 1990s in the environment (17 C, 1 P)N 20th-century natural events (2 C) 20th-century naturalists (3 C, 114 P) Non-renewable resource companies disestablished in the 20th century (56 C) Non-renewable resource companies established in the 20th century (98 C)P Protected areas disestablished in the 20th century (9 C) Protected areas established in the 20th century (11 C, 1 P)R Renewable resource companies disestablished in the 20th century (6 C) Renewable resource companies established in the 20th century (10 C)S Species described in the 20th century (107 C)
