But the effect of society’s choices over family size is undoubtedly worth considering in terms of the effect on climate change.

Some close to the Copenhagen negotiations feel that its the elephant in the room.

Certainly population growth is a vital determinant of how much humanity consumes, but not on the official agenda for those urgent talks to limit global carbon emissions.

So a delicate issue, yet today, for the first time the United Nations issued a report linking demographic pressures to climate change.

Thoraya Ahmed Obaid, executive director of the UN Population Fund told me today that ‘this is the first time we are clearly speaking about the link between population growth and climate change’.

In 1994 in Cairo the UN did say that population was linked to environment, but this is the first time the body has linked it specifically to climate change.

The report quotes an intriguing study which says that putting the world into a low population growth path, leading to 8 billion rather than 9 billion people on the planet by 2050, would save 2 billion tonnes of carbon dioxide emissions.

But it’s not just that: there’s a huge wedge of the world’s population soon to come to child-bearing age … so is the answer for those rapidly growing countries to adopt coercive Chinese-style single child policies?

No, says the UN, this is not about forced population control, but enabling women to decide for themselves to have less children.

Education, empowerment of women, and contraception can all help mitigate climate change, says the report.

Of course almost all the likely growth in world population is happening in developing countries who emit far less Carbon than for example a child in Europe or America.

It’s the process of development that will see that population growth be increasingly carbon intensive.

The middle class in the world – earning at least $8000 a year stands at around 800 million now but is forecast to grow rapidly in the next two decades to 2 billion by 2030.

That’s two billion people who want to fly in planes, drive cars and eat lots of carbon intensive meat.

But that development will also naturally limit population growth as people become richer. so it’s a complex picture.

For now this is a new direction for the UN – the suggestion that condoms aswell as low carbon cars, can limit climate change. But it won’t be discussed in Copenhagen.

But now it seems all the security is in the wrong place. The latest US terror alert issued yesterday is not warning of a possible attack against any of the world leaders visiting here or the United Nations itself. The most dangerous places in the city are apparently the sports stadiums. That’s where the police say they are now expecting the next Al Qaeda attack - a ball game is more likely to be hit than tomorrow’s meeting of the security council.

The Feds are warning that an Al-Qaeda training manual specifically lists “blasting and destroying the places of amusement, immorality, and sin … and attacking vital economic centres” as desired targets of the global terror network.

A joint statement from the Department of Homeland Security and the FBI said while the agencies “have no information regarding the timing, location or target of any planned attack, we believe it is prudent to raise the security awareness of our local law enforcement partners regarding the targets and tactics of previous terrorist activity.”

They obviously don’t realise that all of their local law enforcement partners in New York (I assume they include the NYPD) are patrolling the weird array of protests outside the United Nations building.

Still, since it appears that the NYPD accidentally blew the surveilance of a terrorist suspect this month by questioning one of his friends about him, maybe the FBI will be happy if all the cops are kept out of the way.

Having been denied permission to erect his huge Bedouin tent anywhere in the city he’s had to sleep in the office block that also serves as Libya’s diplomatic HQ at the UN.

We saw him leave there this morning serenaded by a large anti-Libyan protest. But he has managed to put his tent up. 45 miles away in Bedford, Westchester in upstate New York.

Pictures of the tent - which we assume he wants to use to entertain his pals – have outraged local residents and the local council have issued a “stop work” order on the tents construction but they were too late – the tent is up and we don’t know when it might come down.

It’s in the garden of a huge property owned by Donald Trump. He says it was rented out to “mid east partners” and he’s investigating if they are sub-letting to Libya. Gaddafi will be in good company if he ever gets to visit his tent. The neighbours include designer Ralph Lauren and America’s answer to Delia Smith – Martha Stewart.

We’ll see if the tent remains standing long enough for Gaddafi to be able to invite the neighbours in for tea.

But of course someone asked it anyway.

One of the American diplomats shot back – maybe it will encourage the UN to invest in some electric cars.

The Americans are by far the worst offenders. They have the longest motorcades with the heaviest vehicles in them and they don’t seem to be in a hurry to replace any of them with electric models anytime soon.

It would be too hard for the secret service to look tough and menacing in an SUV that hummed like a lawnmower. But it’s not just the queues of cars that are polluting the east side of Manhattan.

I spent a lot of my day hanging out by the very long line of satellite trucks parked outside the UN building. All of them running their engine constantly to generate the power needed for all those live broadcasts.

Chocking us with the fumes at the same time. But that’s not the worst of it. Nearly every one of the correspondents, producers, camera operators and editors that are attached to the live broadcast trucks flew in here, with all their heavy equipment, to cover a climate change conference.

And the irony really does seem to be lost on the media.

We are all very quick to criticise the politicians who do the same, quick to bark questions at Al Gore who is on an almost perpetual global journey to warn of the dangers of rising carbon emissions. But we are extremely slow to turn the same spotlight of hierocracy on ourselves.

Our Channel 4 news team only had to travel to from Washington DC to get to New York so our short one hour flight won’t be the worst offender among the press corps – but is that really an excuse?

Like Al Gore every one of us would argue we have to be here to draw attention to the problem and scrutinise the world leaders who claim to be doing their best to arrest rising world temperatures.

But there are an awful lot of journalists here, an awful lot, and we may all need to start asking questions of each other as well as our leaders.

The ‘there’, was here, in Geneva, the UN’s other home. Ban Ki-Moon came in at 9am, spoke for 10 minutes and disappeared.

A well-honed, well-delivered speech, but no sense of occasion or presence. Behind him, however, a phalanx of heavyweight talent.

Pascal Lamy, the Director General of the World Trade Organisation – dynamic, brusque, no nonsense and the man whose mere invitation had ensured that the others all turned up, including Ban Ki-Moon.

Angel Gurria, the charismatic orator who heads up the OECD came next. Behind him Robert Zoellic the American former trade secretary now head of the World Bank, who is again extremely impressive in the flesh. Dominique Strauss-Kahn of the IMF. Helen Clark, the former New Zealand Premier who heads the UNDP. The cast went on and on.

What struck me was that these global institutions are currently in exceptional hands. But what also struck me was that the representative bodies that tag around in their wake are amazingly cumbersome. The room at the WTO sported a delegate and some sort of support from virtually every member state of the United Nations.

Hundreds and hundreds of thousands of air miles had been burnt to get them to the event. Their capacity to interact with these speakers was limited by the size of the room and the length of the day. The whole thing might have been infinitely more effective had it been done via a video-conference online.

The event? I have got this far without even mentioning it; it was a review of the Aid for Trade project – about countries in the north assisting in developing the trading capacity of countries in the south by investing infrastructure and systems that will level the trading playing field. This while the latest trade round, the ‘Doha round’, is stalled (incidentally everyone I spoke to felt the deal at Doha was there for the taking if only the Americans (and a few others) will get behind it).

The session I ‘facilitated’ followed Ban Ki Moon’s. It started with a highly structured debate.

Then the EU Development Commissioner Louis Michel, who was on my panel, turned to me and whispered: “This is boring – get them to stop reading.”

So I did, I banned all pre-prepared scripts as delegates and panellists had simply been reading from prepared statements.

Suddenly the whole thing lit up and people said what they meant.

Sounds boring I know, and in some ways it was, but it was a fascinating insight into power, powerlessness and the state of global institutions in a globalised world where globalization itself has run into such thunderstorms.

I will do another session today – likely to be far more interesting, to which I will return in my next Snowblog.

He travelled down the so-called “Afgoye corridor”, which houses the biggest concentration of displaced people anywhere in the world.

The corridor is the 19 mile road from Mogadishu to the town of Afgoye and it is lined with the homes of around 400,000 Somalis, living in makeshift huts in temperatures around a hundred degrees.
 
Islamist militia, gangsters and warring clans have made the corridor so dangerous that the WFP’s Somalia Director admits that he hasn’t been able to visit Afgoye himself in 18 months.

And shortly after we got our film footage safely out of Afgoye, a Somali journalist was kidnapped by masked gunmen there and held for five days. But the real story in Afgoye is the plight of its people.  
 
There is no more startling evidence of that than in the feeding centre run by a small and remarkable team of Somali doctors from Medecins Sans Frontieres. 

We met Abdullahi Noor who is just 16-months-old. He’s dangerously close to dying from a lack of food and water. A tiny victim of what may be the worst and least reported humanitarian crisis anywhere.
 
“I cannot move because of hunger” said Fatima Abdirhaman, a mother of four children too exhausted to lift herself off the ground. “I have nothing, nothing to eat. I ate a small amount of porridge yesterday, and that was the last thing I had.”
 
In the four days Channel 4 spent filming in the camps, the only food seen by our producer was boiled leaves, often harvested by children. At the camps we visited, elders repeatedly blamed the World Food Programme for diverting aid away from desperate people.
 
“It is absolutely true that the WFP brings in a very large quantity of aid” said Sheikh Mukhtar, leader of the “Ifis 1″ camp which houses 310 families. “What happens is that they bring the food here to prove it has been delivered, but then only offload a small amount and take the rest back with them to the market in Mogadishu to sell.”
 
Afterwards the Sheikh pointed to the roadside graves of those children who had not survived. 28 children dead, he said, in the last six months. “We are at the mercy of gunmen if we go back home” he continued, “and if we stay here we are dying like flies.”
 
In the Bisharo camp which houses 700 families, camp leader Moallim Mohamed said his people had been forced to pay for ration cards and for the armed guards accompanying WFP staff.

“This is not a one off, this is regular,” Mr Mohamed said. “We pay the gunmen, we pay the man who gives out the cards. If we don’t pay up, they just cover the truck up, open fire on us and drive away. Even on the last trip, they fired at us and eventually we paid them money. I paid the money myself!”
 
The WFP say that these kinds of activities are likely to be carried by local militia demanding protection money and are unrelated to WFP personnel.

They say they have more than doubled their staff, and improved independent monitoring.

The WFP operation is run from the Kenyan capital, Nairobi, which is 765 miles from Mogadishu by road. I spent a week there, talking about what we’d found out with as many aid workers and diplomats as I could, as well as officials from the UN and WFP themselves.

Nobody would deny that Somalia is one of the most complex and dangerous countries in the world to work in.

But the overwhelming sense I came away with was one of deep concern that a vital operation which feeds 3.5 million Somalis may have crossed the line, in terms of its accountability both to its donors and to the very people it is there to help.

Watch Jonathan Rugman’s report on Channel 4 News at 7pm, Monday night or read more online now.

The Israeli prime minister’s spokesman, Mark Regev, this morning drew attention to the UN’s “clarification” over this incident in an interview on Radio 4’s Today programme.

It’s the first time that the Israeli government itself has talked about this clarification in the international media. Because what happened in Jabaliya on 6 January is something I’ve looked into in detail, I’d like to clarify a couple of points myself.

Israel is apparently seizing on a minor error buried in an online publication by a UN agency. Other observers who’ve followed this little row believe this rather manufactured controversy is serving as a smokescreen, diverting attention from a much more serious incident that occurred on the last day of the war at another UN-run school just 800 yards up the road in which children were killed and others badly burned by white phosphorus.

Mr Regev, among other Israeli spokespeople, has suggested in the past that the UN was not entirely impartial in this conflict.

To recap: Israeli mortars, reportedly aimed at a Hamas rocket-launching team, slammed into a street crowded with civilians on 6 January. The mortars stuck within yards of the UN-run Jabalya Prep Girls’ School which at the time was sheltering 1,368 refugees from the conflict.

The Israel Defence Force initially claimed the militants had been firing from inside the school, then changed its position to say they’d been firing “in the vicinity of the school.”

The UN Relief and Works Agency (UNRWA) – the UN’s lead-agency in Gaza, which administers the schools and looks after one million Palestinian refugees – said from the outset that the mortars hit outside the school.

But another UN agency, the Office for the Coordination of Humanitarian Affairs (OCHA), in one of its reports on daily incidents, erroneously stated that the mortars had actually hit the school. This prompted a clarification from OCHA earlier this week and an article in the Israeli newspaper Haaretz.

The Israeli prime minister’s spokesman, Mark Regev, in his interview on Today at 08.40 this morning was asked about the morality of the conflict and the killing of civilians. In response, Mr Regev said it is “important to investigate everything we did.”

He quickly added that “it is important that other organisations also look into what happened and how they played a part in the conflict, negatively.”

“What do you mean?” he was asked.

“Well like the United Nations,” he ventured, “that said they were 99.9 per cent sure about what happened at the school, put out a correction earlier this week saying the Israeli shells didn’t actually hit inside the school.”

Mr Regev’s statement was not challenged.

But it was misleading, a salvo in the public relations war that’s still raging nearly three weeks after the conflict stopped.

UNWRA, the agency which has always maintained the mortars hit outside the school, also said at the time that it was “99.9 per cent sure” there were no militants inside the school.

The other agency, OCHA, had made a mistake in its daily report on 7 January. The notion that it was a genuine mistake (and not a politically motivated untruth) is reinforced by that fact that OCHA had reported correctly on the previous day that the shells hit outside the school.

The Israeli government has had less to say about another incident at a nearby UN school just up the road which occurred on 17 January. At 6.45am, four airburst white phosphorus shells exploded above the playground of the Beit Lahiya primary school, in which 1,600 civilians had taken refuge. It was the last day of the war.

While women and children were evacuating the buildings in panic (and we obtained mobile phone footage documenting all this), an artillery shell slammed into a first floor balcony, killing two boys, Bilal and Mohammed, blowing the hand of their mother and the legs off their 19-year-old female cousin. Here’s a link to my report of this incident.

I reached the school on 19 January and I saw the white phosphorus for myself. An Amnesty International investigator said there was prima facie evidence of a war crime. Mr Regev told Channel 4 News on 22 January that Israel was investigating allegations it had used white phosphorus in civilian areas, something which is illegal.

UNRWA has demanded an independent investigation into this incident. As the OCHA report into it pointed out: “A total of more than 50 UN facilities sustained damage since 27 December. There are no bomb shelters in the Gaza Strip, and no alarm systems to warn of impending bombardment.”

Presumably this is one of the incidents which Mr Regev says it is important that the IDF investigates.

Today we contacted the IDF. They confirmed the 6 January incident was indeed still under investigation. They added:

“Regarding the alleged incident on the 17 of January: The IDF has no information on the alleged incident. However, it is well known that the area of Beit Lahiya, located in the northern Gaza Strip, is in close proximity to Israeli territory and is therefore used extensively by Hamas for launching rockets and shells at Israeli citizens.

“Hamas is also known to use civilian structures, including schools, for its terrorist attacks, thereby actively using children as human shields.”

As far as we can ascertain, the incident involving the phosphorus bombs at the Beit Lahiya school is not the subject of any investigation.

“The United Nations has reversed its stance on one of the most contentious and bloody incidents of the recent Israel Defence Forces operation in Gaza, saying that an IDF mortar strike that killed 43 people on 6 January did not hit one of the United Nations Relief and Works Agency schools after all.”

The article quoted the UN humanitarian co-ordinator in Jerusalem as saying that the UN “would like to clarify that the shelling and all of the fatalities took place outside and not inside the school”.

The United Nations spokesman, whom I’ve just called, is very unhappy about what’s being reported in Israel about this incident.

As one of the first western journalists to get into Gaza, I wanted to investigate exactly what did happen in Jabaliya, on the northern fringes of Gaza City, on 6 January. At the time, it was the single bloodiest incident of the war. It had been widely reported by western journalists – none of whom was allowed into Gaza – that the school itself was targeted.

I have examined what was actually said at the time by the UN and by the Israelis. I also went to the scene, when I finally got into Gaza via Egypt, to hear first hand from local residents – and from the headmaster of the UN-run al-Fakhura primary school in question. At the time of the “missile” strike, the school was sheltering nearly 2,000 refugees. The IDF had the school’s co-ordinates.

What is not contested, at time of writing, is that 43 people died. What is also absolutely clear is that no one inside the school was killed – a fact the UN is accused of twisting.

From the very outset, the UN said that the bombing took place outside the school. UNRWA, the UN Relief and Works Agency which administers refugee assistance in Gaza stuck to that.

John Ging, Director of UNRWA operations in Gaza was quoted by The Guardian as saying that three shells had landed “at the perimeter of the school”. This is accurate.

Another branch of the UN, its humanitarian affairs agency (OCHA) also reported in its daily output of 6 January that the missile strikes had been outside the school. In its report of the following day, however, it mistakenly said the school itself had been attacked. This error was corrected earlier this month.

But it is this error that has been seized upon by the Israelis.

Ironically, the IDF spokesman Major Avital Leibovitz, told Alex Thomson in a live interview in Jerusalem on the night in question that “two Hamas militants,” whom she named as Amar Abu Askar and Hassan Abu Askar, “were in the building and firing rockets.” The IDF later changed its story from saying Hamas militants were inside the school to telling foreign diplomats that the militants had been “next to the school”.

When I went to the scene, I found the impact marks of three mortars in the middle of the street outside the school. The closest of these (and they were all within a few yards of each other) was about 20 yards from the distinctive blue-and-white wall of the school.

An investigator with Amnesty International who visited the same site independently told me she had found a fourth impact mark. An independent munitions expert identified the strike patterns as those of mortars. The IDF uses GPS-guided mortars, which are highly accurate. Surrounding buildings were splattered with the pockmarks of shrapnel.

Local residents in the street told me that militants had been firing rockets – as the IDF claimed – and having been targeted in retaliatory fire by the IDF, they ran down the street past the school. That’s when the mortars apparently landed. The street was full of people at the time, hence the allegation that most of those killed were civilians. I was unable to find out whether the militants were among the dead.

The headmaster of the al-Fakhura school told me that four people inside his school were injured by shrapnel from the mortars, but that the only person killed was one child who happened to be in the street outside at the moment of impact.

This may sound like a lot of detail to go into – but when it comes to determining whether or not customary international humanitarian law may have been breached (as has been alleged), this is the sort of detail that can be important. Although a large number of civilians were apparently killed, all this may prove to be evidence which works in Israel’s favour as it’s pretty clear that the school itself was not the target.

The other reason I think it’s important is that by seizing on one factual error by the UN – which was corrected anyway – the IDF fuels the suggestion that the UN’s account of an incident in which 43 people died is a fabrication.

UPDATE: The IDF’s Gaza Coordination and Liaison Administration has since claimed only 12 people, including nine “Hamas operatives”, were killed in the incident rather than 43. A later video report on the dispute over how many people died in the conflict overall is here.

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