Short answers, pulled from the story.
The WHO designated tobacco the world's single greatest preventable cause of death in 2008 because tobacco kills more than 8 million people every year worldwide, including about 1.3 million non-smokers who die from exposure to secondhand smoke. The WHO estimated tobacco caused 100 million deaths over the entire 20th century.
The word tobacco traces back through the Spanish tabaco to the Taíno language of the Caribbean. Bartolomé de las Casas, writing in 1552, recorded that the term referred to a roll of tobacco leaves, while another account linked it to a Y-shaped pipe called a tabago. Similar words also appeared in Spanish, Portuguese, and Italian as early as 1410, possibly derived from the Arabic ṭubbāq, a term for various herbs dating to the ninth century.
The chief commercial tobacco crop is Nicotiana tabacum. Seventy-nine species of tobacco are known in total, but N. tabacum dominates global production. The more potent variant Nicotiana rustica is also used in some countries.
China is the largest tobacco producer, accounting for about 36.3% of world production, followed by India at 12.9% and Brazil at 11.9%. Every year, roughly 5.9 million tons of tobacco are produced globally. Zimbabwe is also among the top producers.
In drug-effect preference questionnaires, nicotine scores almost as highly as opioids as an indicator of addictive potential. One medical study ranked tobacco's overall harm to users and others as sixth most harmful among 20 drugs assessed, placing it three percentage points below cocaine and 13 percentage points above amphetamines.
Tobacco was central to the origins of genetically modified plant science. The first genetically modified plant was produced in 1982 using Agrobacterium tumefaciens to create an antibiotic-resistant tobacco plant. Transgenic tobacco then became the first GM crop tested in open field trials, in the United States and France in 1986, and China became the first country to approve commercial planting of any GM crop in 1993 when it approved GM tobacco.