To say electronic cigarettes ignite controversy is an understatement.

For some, e-cigarettes offer the prospect of disrupting the $800 billion global cigarette trade by providing a satisfying alternative to smoking. Nicotine itself is not a carcinogen, and e-cigarettes do not have all of the toxins and carcinogens produced by burning tobacco that cause half of all long-term smokers to die prematurely.

For the other side, e-cigarettes look more like Big Tobacco bouncing back with a dangerous new way to hook kids and keep people smoking.

Who’s right?

E-cigarettes have been on the market since 2007, but only now are we starting to see their impact. For anyone willing to take a dispassionate look at the emerging data, the news is good for those inspired by the prospect of e-cigarettes crowding out tradition smokes. Consider five important observations:

First, in the mid-2000s, the share of Americans who considered themselves current smokers declined to about 20 percent. Then that decline in smoking stalled, picking up again with the advent of e-cigarettes.

Second, during the rise of e-cigarettes, smoking rates in the US adult population have fallen to their lowest rates in recent history. According to new data released last week by the Centers for Disease Control and Prevention, the proportion of American adults who smoke has fallen each of the past six years, from 20.6 percent in 2009 to 15.2 percent in early 2015. In the past year, the smoking rate fell by 10 percent — the largest single-year decline in the last 18 years.

Third, fears of young people becoming addicted to e-cigarettes or e-cigarettes serving as a “gateway” to smoking remain speculative. To the contrary, youth smoking rates have continued to drop at unprecedented rates, and are already below the government target for youth smoking for 2020, more than five years ahead of what had been a very ambitious schedule.

Fourth, there are now at least 2 million ex-smokers using e-cigarettes in the United States. While we can’t be certain that they are ex-smokers because they are using e-cigarettes, there are thousands of powerful testimonies of “vapers” who quit smoking using e-cigarettes after having tried everything else.

And fifth, though we can’t yet be certain of all of the long-term health impacts or benefits of e-cigarettes, that doesn’t mean we know nothing.

Thousands of experimental measurements have been made that show that the important hazardous chemicals in combustion cigarette smoke are mostly not present in e-cigarette vapor, or are present at levels that give less cause for concern. Based on what we know today, there is broad agreement that e-cigarette use is significantly safer than cigarette smoking.

The American experience is mirrored across the Atlantic. In August, Public Health England, an agency of Britain’s Department of Health, issued a 111-page report on electronic cigarettes that carefully addressed every significant concern that has ever been raised about these products.

PHE found that e-cigarettes are almost exclusively used by those who have already smoked and rejected the claim that they are attracting nonsmokers. They also showed that both adult and youth smoking continued to decline while e-cigarette use has grown.

And based on the available information, PHE concluded electronic-cigarette use is likely to be around 95 percent less harmful to health than smoking.

PHE is the first public body to declare its support for e-cigarettes. PHE declares its ambition to achieve a tobacco-free generation by 2025, and it believes that “e-cigarettes have the potential to make a significant contribution to the endgame for tobacco.” I share their ambition and believe that many of my colleagues in public health do as well — as do many in the private sector.

We now need to agree on how to make this work. The time has come for such responsible companies within this industry (with one of whom I am now affiliated), and the government and public health (where I have spent a good part of my career) to work together to find ways to accelerate the historic obsolescence of traditional smoking with rapidly advancing cleaner new technologies.

Millions of lives depend on it.

Former US Surgeon General Dr. Richard Carmona authored many federal warnings regarding tobacco use. He serves on the board of NJOY, an independent electronic-cigarette company that has the mission of rendering the tobacco cigarette obsolete.