A major research institute in Washington, DC, Pew Forum on Religion and Public Life, is predicting, in a study called the Future of the Global Muslim Population, that the global Muslim population will grow by more than a third over the next two decades - with significant increases in Europe and the United States.

The Pew Forum's Associate Director of Research Alan Cooperman said one of the main findings is that the Muslim population worldwide is expected to grow at about twice the rate for non-Muslims. "So if current trends continue, Muslims will make up 26.4 percent of the world's total projected population of 8.3 billion people in the year 2030," he said.

In America, researchers said Muslims will double in number to more 6 million in the next twenty years. That would make them as numerous as the current population of Jews or Episcopalian Protestants.

The Pew report says the Muslim share of Europe's population is expected to grow by nearly a third to 58 million.

However, researchers said there's no evidence that Islam may one day be the dominant culture in Europe. This is a prediction by the European far right known as the Eurabia hypothesis. Pew researcher Brian Grim says it is not supported by the current trend in which the Muslim share of the total European population increases by 2 percent every twenty years. "It would take many, many years. And there's no real scenario, that we've looked at, that this Eurabia scenario would come to be," he said.

One place where the Muslim population is growing fast is within Israel. Researchers said it has doubled in absolute terms since 1990, and is expected to continue to rise from around 18 percent of the total population currently to 23 percent in 2030. Grim said that is the largest percentage increase in any country in the world.