Deep inside the waterways of the Nile Delta, it is hard to believe that this region is in an environmental crisis. It is an idyllic setting as the canoes of fishermen drift through the swamps; kingfishers and egrets fly overhead, and reeds glisten in the early morning sunshine.
But the fishermen are not happy. They say their catches are down, and that the water is more and more polluted from nearby factories.
There is certainly enormous pressure on the Delta's resources; most of Egypt's 80 million people are crammed into this fertile, green landscape, where the Nile ends its epic journey half the length of Africa, and fans out into a series of tributaries and lakes, before flowing into the Mediterranean.
I ask the fishermen if they know about global warming, and the threat to the Delta posed by the possibility of sea-levels rising. They say they have heard about it, but have seen no evidence yet.
We leave the fishermen, and drive north, closer to the Mediterranean coastline. Our engaging guide is Mamdouh Hamza, a prominent Egyptian engineer and head of a company that specialises in underwater construction.
Hamza stops his car, and leads us out into some sandy wastes by the side of the road. We can see abandoned crops, and dying palm trees. He says the land has been destroyed by salinity, or salt.
Rising salinity levels
|Mamdouh Hamza says rising salinity could lead to economic and agricultural disaster
As the sea on Egypt's coastline rises, (Hamza says by 20cm during the last century, a statistic that leading Egyptian government scientists concur with) salt-water infiltrates the Delta's soil from below, and destroys the farming land.
The consequences of this are very serious for Egypt, which relies on the Delta for food production.
Today, as Egypt's population continues to grow, and as it spends more and more money on food imports, the country cannot afford to lose any more productive land. Gesturing to the salty wastes around me, Hamza says: "It is a human disaster, an economic disaster, an agricultural disaster, and it will lead not only to poverty but also to hunger".
Of course, predictions of future changes in sea levels, mainly resulting from melting of the polar ice-caps, are very imprecise.
Last year, Egypt's environment minister, George Maged, told a parliamentary committee that "many of the towns…in the north of the Delta will suffer from the rise in the level of the Mediterranean with effect from 2020, and about 15 per cent of Delta land is currently under threat from the rising sea level and the seepage of salt water into ground water".
Many experts believe that a one-metre rise in sea-level on Egypt's coastline by the end of this century is a reasonable prediction, which, if true, would threaten the great city of Alexandria, and the millions of people who live in it.
Hamza has submitted an ambitious proposal to build a waterproof wall that he argues would effectively separate the sea from the land, prevent salt water seepage, whilst at the same time raising the shore by 2 metres, but, so far, the government has not taken him up on it.
One government scientist I met with, Professor Ibrahim El Shinnawy, is not convinced that such dramatic steps need to be taken yet.
He says, "we are recommending more investigations, but we think we can adapt ourselves to this problem, as the rate of change is very slow". In other words, there is still time " to put the best mitigation measures" in place.
In truth, there are any number of factors now damaging the ecology of the Delta. Ever since the completion of the Aswan High Dam, 40 years ago, soil fertility levels in the Delta have been falling, as large quantities of sediment are no longer washed downstream.
Hamza and I walk across from the abandoned land, to a plot that is still being farmed. We meet the owner, Abdel Fattah Ghoneim, 40, who tells us about the growing difficulties of making a living here in the northern Delta. He has to pump in fresh water, he says, whereas in the old days "there was enough rain, you didn't need to do anything more".
And, because the ground "is so salty" he has to buy hundreds of bags of sand, to lay on top of the ground and protect his crops from salinity. "Twenty or 30 years ago, we could just plant our seeds and not worry about anything else," Ghoneim says.
"But now, those days are over."