KHAN YOUNIS (Reuters) — As the world’s population reaches seven billion, there are few places in the world where explosive demographic growth is having such a significant impact as Gaza.

In less than half a century, the number of people on the planet has doubled, and sometime on Sunday the world’s population passed the seven billion mark, according to the United Nations Population Fund.

In Gaza, 1.7 million people are crammed into a living space measuring about 41 kilometers long, and between six and 12 kilometers wide, with a total area of 360 square kilometers. Almost three-quarters of them are UN-registered refugees.

“There is no space. We are not living in a good situation. The number of people continues to grow and there is no space,” Gazan Khalil Ahmed told Reuters Television.

The population explosion is set to continue, according to the Palestinian Central Bureau of Statistics, which reported that the annual growth rate of 3.3 percent is higher than the world’s average rate of 1.4 percent.

The head of PCBS Ola Awad warns that the population in Gaza will exceed two million by 2020.

“Until 2020 we expect that the population in the Gaza strip will reach two million and 130 thousand estimating the annual growth in the Palestinian territories,” she said.

Awad said a combination of cultural, social, political and historical factors are behind the continuing high birth rate, notwithstanding the endemic poverty and lack of opportunity as a result of the Israeli blockade. But she is unequivocal that this ticking demographic time bomb has serious implications for Gaza’s future and its fraught relations with neighboring Israel.

“The Gaza strip is in a dangerous situation. If we are speaking about Palestinian society we are speaking of a young society. In the Gaza strip people up to the age of 14 make up around 44 percent of the strip’s population. It is a dangerous index,” Awad said.

Hemmed in by land, sea and air since 2007, an Israeli blockade has had a devastating impact on the people of Gaza.

The UN Relief and Works Agency for Palestine Refugees says not only is Gaza already one of the most densely populated parts of the world it is unique in being fenced-in, offering no escape for residents in times of conflict.

“Gaza is one of the most densely populated parts of the planet. So a rise in population in such a confined community is going to have an enormous impact.

“We already have a situation where unemployment is very high. Where there is not proper drinking water. Where there is a crisis in every part of the population’s life. So the increase in population in Gaza will be, I think, more acutely felt than in many other parts of the world because it is so densely populated,” UNRWA spokesman Chris Gunness said.

“Gaza is unique in the annals of contemporary warfare in being the only conflict with a fence around it. So when the bombs start falling there is nowhere to flee. There’s nowhere safe in Gaza and given the UN installations were hit even the UN cannot necessarily provide a neutral security zone. So it is a real problem. The blockade and the incursions that come with it can only make life considerably worse for the population of Gaza,” Gunness added.

Israel has long restricted the entry of goods into the coastal enclave but it tightened its blockade in 2007 after Hamas wrested control of Gaza from its rival Fatah. Denied the building blocks of forging a meaningful society and functioning economy, the blockade has plunged 67 percent of people below the poverty line, surviving on less than two dollars a day.

Before the embargo, many Palestinians worked in Israel but the travel ban cut off the only means of earning an income for many families. Today Gaza has the highest unemployment rate anywhere in the world, running at just over 45 percent, according to UNRWA.

The European Union and other international organizations have condemned the land and maritime embargo as a form of “collective punishment,” which is banned under the Geneva Convention. But Israel continues to defy calls to lift its blockade which it says is necessary to prevent militants from obtaining weapons, explosives and ammunition.

UNRWA provides food staples and schools for Gaza’s refugee population. The enclave has no airport or seaport for freight.

Gaza’s pressure cooker atmosphere has been relieved since the fall of Egyptian President Hosni Mubarak this year and a change in policy by Cairo, a party to the blockade with Israel, which now opens the southern border crossing at Rafah daily for civilian traffic, though not for trade.

But UNRWA reports that Gaza’s working-age population (those over 15) is estimated to have grown by 2 percent in the second half of 2010 from the first half, increasing the demand for jobs that do not exist in its broken economy.

“Where can I work? Do you think there are any job opportunities? All the young men are unemployed. What do you think? Go to another place where they will say we do not have jobs. Before we used to work in Israel, we used to work a week in Israel and come back,” unemployed Atya Abdel Hamid explained.

Basma Daka, 24, is due to give birth in two months. The young mother hopes life for her second child will be better, but she is not optimistic.

“Due to the situation we are living in Gaza the future of our children is unclear and not like other children in the world. He will not have the same right of education if we compare him to children in other countries. He will not get the best education. He will lose his right of play unlike like other children in Arab countries,” Daka added.

The current conflict has also prevented women from asserting themselves in regard to their reproductive rights, Gaza’s United Nations Development Fund for Women programmer reported.