The number of cigarette smokers in the world will fall by a minuscule amount in the next 18 years unless significant action is taken, a study claims.
Research published by BMJ Tobacco Control calculates that global "prevalence" (the percentage of the adult population that smokes) will dip by just 1.7 percent by 2030.
The study claims, on the other hand, that World Health Organisation measures could see a drop from just under 24 percent in 2010 to under 13 percent in 2030 if they are put into practice.
More than five million people die from smoking-related illnesses every year - more than the total toll of Aids, tuberculosis and malaria combined.
In the paper, titled The Potential Impact of Smoking Control Policies on Future Global Smoking Trends, researchers from the University of Michigan predict only a gradual decrease in smoking levels.
The study states: "This is mixed news. On the one hand, it suggests that global smoking prevalence is not likely to rise over the next 20 years but on the other hand, it indicates that due to expected population growth, the global number of smokers (at least those within the  countries we studied, constituting approximately 90 percent of the world's smokers) will increase by 10 percent to a staggering 872 million smokers in 2030."
The study suggest enacting six measures suggested by the WHO:
- Tobacco use monitoring.
- Protection from secondhand exposure to tobacco smoke.
- Help to quit.
- Warnings about dangers of tobacco
- Enforcement of tobacco advertising and sponsorship bans
- Tax hikes on tobacco products.
Although many of these measures have been instigated in certain countries, they have not been universally enacted.
The researchers used WHO data to estimate the global prevalence of smoking among adults. They found that China contributed the most to the global smoking tally (28 percent), followed by India (11 percent), Indonesia (4.8 percent), the US (4.7 percent) and Russia (4 percent).
With no additional action on smoking, countries in Europe would remain top of the league of smokers, accounting for 30 percent by 2030. Smoking prevalence would continue to increase in Africa.
However, the study estimates that the WHO measures would drop global prevalence to 15.4 percent by 2020 and 13 percent by 2030, with the largest fall in the proportion of smokers being in Europe.
The study authors are keen to stress that their figures are not forecasts, but rather an indication of possible achievements.
"As approximately half of lifetime smokers die of tobacco-related diseases, implementation of [WHO measures] would prevent many millions of premature tobacco related deaths," the study concludes.