Vietnam is a country in Southeast Asia. Located at the eastern edge of mainland Southeast Asia, it covers 311,699 square kilometres. With a population of over 96 million, it is the world's fifteenth-most populous country. Vietnam borders China to the north, Laos and Cambodia to the west, and shares maritime borders with Thailand through the Gulf of Thailand, and the Philippines, Indonesia, and Malaysia through the South China Sea.
As the country is located within the Indomalayan realm, Vietnam is one of twenty-five countries considered to possess a uniquely high level of biodiversity. It is ranked 16th worldwide in biological diversity, being home to approximately 16% of the world's species. 15,986 species of flora have been identified in the country, of which 10% are endemic. Vietnam's fauna includes 307 nematode species, 200 oligochaeta, 145 acarina, 113 springtails, 7,750 insects, 260 reptiles, and 120 amphibians. There are 840 birds and 310 mammals are found in Vietnam, of which 100 birds and 78 mammals are endemic. Vietnam has two World Natural Heritage Sites—the Hạ Long Bay and Phong Nha-Kẻ Bàng National Park—together with nine biosphere reserves, including Cần Giờ Mangrove Forest, Cát Tiên, Cát Bà, Kiên Giang, the Red River Delta, Mekong Delta, Western Nghệ An, Cà Mau, and Cu Lao Cham Marine Park.
Vietnam is also home to 1,438 species of freshwater microalgae, constituting 9.6% of all microalgae species, as well as 794 aquatic invertebrates and 2,458 species of sea fish. In recent years, 13 genera, 222 species, and 30 taxa of flora have been newly described in Vietnam. Six new mammal species, including the saola, giant muntjac and Tonkin snub-nosed monkey have also been discovered, along with one new bird species, the endangered Edwards's pheasant. In the late 1980s, a small population of Javan rhinoceros was found in Cát Tiên National Park. However, the last individual of the species in Vietnam was reportedly shot in 2010. In agricultural genetic diversity, Vietnam is one of the world's twelve original cultivar centres. The Vietnam National Cultivar Gene Bank preserves 12,300 cultivars of 115 species. The Vietnamese government spent US$49.07 million on the preservation of biodiversity in 2004 alone and has established 126 conservation areas, including 30 national parks.
In Vietnam, wildlife poaching has become a major concern. In 2000, a non-governmental organisation called Education for Nature – Vietnam was founded to instill in the population the importance of wildlife conservation in the country. In the years that followed, another NGO called GreenViet was formed by Vietnamese youngsters for the enforcement of wildlife protection. Through collaboration between the NGOs and local authorities, many local poaching syndicates were crippled by their leaders' arrests. A study released in 2018 revealed Vietnam is a destination for the illegal export of rhinoceros horns from South Africa due to the demand for them as a medicine and a status symbol.
The main environmental concern that persists in Vietnam today is the legacy of the use of the chemical herbicide Agent Orange, which continues to cause birth defects and many health problems in the Vietnamese population. In the southern and central areas affected most by the chemical's use during the Vietnam War, nearly 4.8 million Vietnamese people have been exposed to it and suffered from its effects. In 2012, approximately 50 years after the war, the US began a US$43 million joint clean-up project in the former chemical storage areas in Vietnam to take place in stages. Following the completion of the first phase in Đà Nẵng in late 2017, the US announced its commitment to clean other sites, especially in the heavily impacted site of Biên Hòa, which is four times larger than the previously treated site, at an estimated cost of $390 million.
The Vietnamese government spends over VNĐ10 trillion each year for monthly allowances and the physical rehabilitation of victims of the chemicals. In 2018, the Japanese engineering group Shimizu Corporation, working with Vietnamese military, built a plant for the treatment of soil polluted by Agent Orange. Plant construction costs were funded by the company itself. One of the long-term plans to restore southern Vietnam's damaged ecosystems is through the use of reforestation efforts. The Vietnamese government began doing this at the end of the war. It started by replanting mangrove forests in the Mekong Delta regions and in Cần Giờ outside Hồ Chí Minh City, where mangroves are important to ease flood conditions during monsoon seasons. The country had a 2019 Forest Landscape Integrity Index mean score of 5.35/10, ranking it 104th globally out of 172 countries.
Apart from herbicide problems, arsenic in the ground water in the Mekong and Red River Deltas has also become a major concern. And most notoriously, unexploded ordnances pose dangers to humans and wildlife—another bitter legacy from the long wars. As part of the continuous campaign to demine/remove UXOs, several international bomb removal agencies from the United Kingdom, Denmark, South Korea and the US have been providing assistance. The Vietnam government spends over VNĐ1 trillion annually on demining operations and additional hundreds of billions of đồng for treatment, assistance, rehabilitation, vocational training and resettlement of the victims of UXOs. In 2017 the Chinese government also removed 53,000 land mines and explosives left over from the war between the two countries, in an area of 18.4 km2 in the Chinese province of Yunnan bordering the China–Vietnam border.