there are shorter production cycles which again results in a more efficient use of feed. Besides genetically modified crops and livestock, synthetic biology is also on the rise and environmentalists argue that these also contain risks, if these organisms were ever to end up in nature. This, as unlike with genetically modified organisms, synthetic biology even uses base pairs that do not exist in nature. 21st century In 2022, Global Witness reported that, in the preceding decade, more than 1,700 land and environmental defenders were killed, about one every two days. Brazil, Colombia, Philippines, and Mexico were the deadliest countries. United States Beginning in the conservation movement at the beginning of the 20th century, the contemporary environmental movement's roots can be traced back to Rachel Carson's 1962 book Silent Spring, Murray Bookchin's 1962 book Our Synthetic Environment, and Paul R. Ehrlich's 1968 The Population Bomb. American environmentalists have campaigned against nuclear weapons and nuclear power in the 1960s and 1970s, acid rain in the 1980s, ozone depletion and deforestation in the 1990s, and most recently climate change and global warming. The United States passed many pieces of environmental legislation in the 1970s, such as the Clean Water Act, the Clean Air Act, the Endangered Species Act, and the National Environmental Policy Act. These remain as the foundations for current environmental standards. Timeline of US environmental history 1832 – Hot Springs Reservation 1864 – Yosemite Valley 1872 – Yellowstone National Park 1892 – Sierra Club 1916 – National Park Service Organic Act 1916 – National Audubon Society 1949 – UN Scientific Conference on the Conservation and Utilization of Resources 1961 – World Wildlife Foundation 1964 – Land and Water Conservation Act 1964 – National Wilderness Preservation System 1968 – National Trails System Act 1968 – National Wild and Scenic Rivers System/Wild and Scenic Rivers Act 1969 – National Environmental Policy Act 1970 – First Earth Day- 22 April 1970 – Clean Air Act 1970 – Environmental Protection Agency 1971 – Greenpeace 1972 – Clean Water Act 1973 – Endangered Species Act 1980 – Earth First! 1992 – UN Earth Summit in Rio de Janeiro 1997 – Kyoto Protocol commits state parties to reduce greenhouse gas emissions 2017 – First National CleanUp Day Latin America After the International Environmental Conference in Stockholm in 1972 Latin American officials returned with a high hope of growth and protection of the fairly untouched natural resources.