Just three years earlier, Roubini had been the object of derision in the economics community as he prophesied a US housing market crash, financial crisis and partial collapse of the banking sector. Today, as an adviser to governments and central bankers and much feted in the media, he's well aware of the power of being right.
"In my line of business your reputation is based on being right," he says. "The publicity is just noise. Certainly with a global crisis, the dismal scientists are having some prominence, even if most of the economics profession actually failed to predict it."
The 51-year-old, widely known as Dr Doom, is in town to publicise his new book Crisis Economics, a crash course in the financial crisis and what can be done to avoid another.
The book does little to suggest he is uncomfortable with his nickname. Where Roubini is concerned, the great recession has some way to run.
"The crisis is not over; we are just at the next stage. This is where we move from a private to a public debt problem," he says, his speech the mongrel drawl of a man who was born in Turkey to Iranian parents, raised in Israel and Italy and lives in New York. "We socialised part of the private losses by bailing out financial institutions and providing fiscal stimulus to avoid the great recession from turning into a depression. But rising public debt is never a free lunch, eventually you have to pay for it."
As eurozone leaders panic and markets continue to dive, Roubini believes Greece will prove to be just the first of a series of countries standing on the brink.
"We have to start to worry about the solvency of governments. What is happening today in Greece is the tip of the iceberg of rising sovereign debt problems in the eurozone, in the UK, in Japan and in the US. This... is going to be the next issue in the global financial crisis."
It already is. And Roubini claims to have foreseen it as far back as 2006.
"I was writing about the PIGS [Portugal, Italy, Greece and Spain] six to nine months before everyone else, I was worried about the future of the monetary union back in 2006," he says. "At the World Economic Forum I outraged a policy official by suggesting the monetary union might break up."
Roubini has sandwiched a visit to the The Daily Telegraph's offices between a private meeting with Bank of England Governor Mervyn King – "I regularly meet with policy makers. I don't know if it's even worth mentioning" – and a talk at the London School of Economics. I ask him if I can see his LSE speech.
"I haven't written one. I never prepare a speech, I don't even have notes. I usually just speak out of my own thoughts; stream of consciousness."
It's a manner he adopts when we meet. Looking over my shoulder, declining eye contact, he moves seamlessly between what he describes as the economist's usual suspects – "the US, eurozone, Japan, China, emerging markets, inflation, deflation, markets" – as he must when teaching his 400 students in New York.
The prognosis for all the suspects save China and the emerging markets is grim, little wonder given the backdrop of a 3.8pc drop in the FTSE last week and panic among investors spooked by German chancellor Angela Merkel's short-selling ban. The ban has been dismissed as fiddling while Rome, or rather the eurozone, burns.
Roubini believes Greece's problems will see the country forced to restructure its debt and raises the longer term prospect of a breakdown of the union with the potential exits of Greece, Spain and Portugal.
Could it survive such a blow? "Well you could think of a world where there is a eurozone with only a core of really strong economies around Germany," he says. "But the process that would lead to one or more countries leaving the union would be so disruptive that the euro as a major reserve currency would be severely damaged."
Like many economists, Roubini does not talk in absolute predictions. It is all about what could happen in worse case scenarios.
But he argues they are only becoming more likely under current political leadership, the UK's new Conservative-Liberal coalition included. "I am worried about the hung parliament. Whenever you have divided, weak or multi-party governments, budget deficits tend to be higher. It is harder to make the necessary sacrifices."
He dismisses the £6bn of cuts announced by the coalition as "small compared to what is needed", but rejects the idea that the UK is worse off than many of its peers.
"In the US there is a lack of bipartisanship between Democrats and Republicans, in Germany Merkel has just lost the majority in her legislature, in Japan you have a weak and ineffective government, in Greece you have riots and strikes," he says. "The point is that a lot of sacrifices will have to be made in these countries but many of the governments are weak or divided. It is that political strain that markets are worried about. The view is: you can announce anything, we'll see whether you're going to implement it."
This, he explains, is the ultimate challenge facing governments.
"If you're pushing through austerity while there is growth that's one thing, but if you're pushing it through while the recession is deepening, politically that is harder to sell. And the eurozone doesn't just need fiscal consolidation but also structural reform to increase productivity and restore competitiveness," he says.
Germany is the blueprint, Roubini points out, but "it took a decade for them to see the benefits of structural reform and corporate restructuring".
"If Spain and Portugal start today, you'll see the short-term cost without the long-term benefit and they might run out of political time," he says. "That's why I worry about several eurozone members having to restructure their debt, or deciding that the benefits of staying in the monetary union are less than the cost of it."
The prognosis for the UK is, at least, a little less alarming. An independent currency gives it a few more levers to pull – quantitative easing means default is unlikely to be an issue. But that comes with its own challenges.
"Eventually inflation will go up and that erodes the real value of public debt," Roubini says. "In that scenario the value of the pound will fall sharply. It could even become disorderly and that could damage the economy, the financial markets and also the role of the pound as a reserve currency."
Yet another challenge for Government then. Whether the coalition can live up to it remains to be seen. And whether it thinks it has to.
Roubini is adamant that the great recession is not over. But a temporary economic pick-up, which would convince governments that reform is unnecessary, could bring its own problems.
"People asked me why I saw there was a bubble and my question was why others didn't. During the bubble everybody was benefiting and losing a sense of reality," he says. "And now, since there is the beginning of economic recovery – however bumpy that might be – in some sense people are already starting to forget what happened two years ago. Banks are going back to business as usual and bonuses are back to levels that are outrageous by any standards. There is actually a backlash against even moderate reforms that governments are trying to pass."
Reform, Roubini insists, is necessary, recovery or not. "We are still in the middle of this crisis and there is more trouble ahead of us, even if there is a recovery. During the great depression the economy contracted between 1929 and 1933, there was the beginning of a recovery, but then a second recession from 1937 to 1939. If you don't address the issues, you risk having a double-dip recession and one which is at least as severe as the first one."
Roubini has built his reputation on such forecasts. So, given the real reputation builder was forecasting the crisis, has he been one of the few to enjoy the troubled times of the past few years?
"We are witnessing the worst global economic crisis in the last 60 to 70 years and for an economist that offers an opportunity," he says. "So it has been interesting, but the damage financially and economically has been so severe and so many people have suffered. Anybody involved has to bear that in mind."
