Jeffrey Sachs, the economist and director of the Earth Institute at Columbia University, speaks with a velvet tongue but packs a mighty punch.

Big business, he says, is not responsible only for destroying the American democratic system, but has also transformed citizens into consumer addicts.

While multinationals continue to line their own pockets, what they leave in their wake is billions of people who are not only unhappy, but are suffering increasing levels of anxiety.

While a few companies are serious about dealing with the sustainability challenges of our age, Sachs says many more are still engaging in green washing, while he describes the fossil-fuel lobby, and the Koch brothers in particular, as "disgusting."

A dangerous direction

Not only is Sachs clear that the old economic paradigm, which is based on a fixation of GDP growth, is leading us to disaster, but that we need to find a completely new way of measuring the success of society.

Sachs, who amongst many roles is special adviser to UN secretary-general Ban ki-Moon on the millennium development goals, believes the creation of a set of sustainable development goals (SDGs) could be one route towards achieving that.

His particular interest is in developing a measure for wellbeing and happiness and he recently co-organised a major conference on the subject at the UN in New York, in partnership with the Himalayan kingdom of Bhutan.

I caught up with Sachs at the Rio+20 conference where he is keeping up a punishing schedule, engaging in several public and private debates ranging across the public policy sphere, from poverty to education.

"The point of the move to better metrics is the realisation that not only does gross national product not measure properly what makes us well-off and satisfied, it is leading us now in a very dangerous direction," he told the Guardian. "If we continue to follow that indicator we will follow a path right over the cliff.

"One of the key planks of the SDGs is that we need better measurement of wellbeing and one way is to ask people how well are you doing, life satisfaction. A legion of scholars have been studying this and picking up great traditions as brought by Buddhism and Bhutan in particular. We can now identify pretty systematically places were people are deeply unhappy, highly anxious and also identify systematically the reasons why.

"Money matters and especially for the poor. But once you reach a certain level of wellbeing, the additional gains are very small and perhaps not there at all. The US has tripled its per capital GDP over the last 50 years but there has not even been a twitch of the needle in raising wellbeing.

"Second, people are, like Aristotle said, social animals. We depend on our sense of participation in communities and if there is a lack trust, our lives are miserable, and if we live in unhappy places where people do not co-operate with each other and altruism is not a moral virtue that is defended, where cheating is rife and pervasive, then unhappiness soars and this is one of the most important findings of US sociology over the past 25 years.

"Americans do not trust each other, and there is so much cheating and illegality and this raises the third point, which is when people do not trust their governments to be fair honest and transparent, their own personal happiness suffers a lot."

A breakdown of modern democracy

Sachs, who became known for his role as an adviser to Eastern European governments during their transition from communism, says business has a major responsibility for the mess we are in, but also has great respect for the ability of multinationals to operate effectively on a global scale.

"I deal with a number of businesses that I admire because they are better diplomats than the state department as they are actually doing things rather than talking about them. They are getting real things done," he says.

"The other face of businesses is that they are too powerful in our societies. They write the rules, they pay the politicians, sometimes illegally and sometimes, via what is called legal, which is financing their campaigns or massive lobbying.

"Billions of dollars are spent and this is horrendous because if business writes the rules, it is not true their shareholder value is their value to society. It can reflect highly destructive practices which the politicians turn their eyes away from because of the political power companies hold. This has got completely out of control and is leading to the breakdown of modern democracy."

Drawing a line between big business and politics

Sachs says he has spoken to a number of CEOs recently and that lots of them would love to sign up to a no lobbying platform, but they feel they can't while their competitors are still engaged in it.

So he is pinning his hopes on young people leveraging the power of social networking to break the business stranglehold. One way would be to have a presidential candidate in 2016 who refuses to take any single contribution beyond $100 and uses social media to raise funds and get the message out to the voters, rather than using hugely expensive television campaigns.

He says: "The one thing these companies do not have is the vote, but the money to distort votes and the public is more and more onto this, but in the US they are profoundly cynical and very unhappy. Both political parties are in the pockets of big business."

Social media and consumerism

It is not just the way business controls politics that worries Sachs, but also their use of marketing in such an insidious way that people now value their lives according to the goods and services they buy.

While social networking has the power to break the existing power structures, Sachs also recognises its power to enslave us further to consumerism.

"It is striking to me that you look at Facebook and social media and these are the hot things but what is the business proposition of Facebook – more personalised advertising," he says.

"That is where the whole money proposition is that advertisers can learn how to more personalise the things exactly to hit your hot button.

"It is no secret we fell into a mass consumerist mentality. We fell into an era where the tools of mass persuasion are so powerful and bombard us daily so that happiness is defined by what is advertised.

"We have gotten into a self feeding cycle which is extremely dangerous. We are being sold things that are not raising our wellbeing and are often lowering it. Our health is breaking down, our anxiety is increasing, people not only watch too much television and eat too much fast food but they know it and then they spend tremendous amount of psychic effort and money to try to resist their own impulses which are built in and have become almost addictive."

Sustainable Development Goals

Sachs says the SDGs could be transformative for society because they can fire up the public imagination. But he is very clear they need to be simple so that even a child can understand them.

"I have been involved in the MDGs for a dozen years," he says. "They are not a treaty, they are not binding, they don't have the force of international law, but have had the force of inspiration and changed behaviour and motivated communities, governments, NGOs, companies and the broad public to take action.

"The point of the SDGs is that they need to be globally agreed goals, clear and time-bound and understandably broadly, not highly complex and esoteric.

"We are here in Rio 20 years after the adoption of three powerful, well crafted, forward looking treaties, on climate change, biodiversity and combating desertification. Not one of those has delivered what it set out to do because they became hostage to technical insider negotiations rather than a broad public movement to save the planet and that is what we need right now."

Sachs says it is vital that a clear framework for the SDGs is agreed by September 2013 when the UN holds a special assembly to have a final review of the MDGs, but that this is by no means a certainty.

"If we do that by then, we will keep the pace," he says. "But they will not serve any purpose if we have another highly fractious bitter debate or a Christmas tree of demands that ends up 300 pages long like Agenda 21."

A fresh approach

What is particularly interesting about Sachs is that he has taken a multi-disciplinary approach to seeking solutions to the world's most intractable problems. At the UN conference on happiness, he held a day long workshop that did not just include the usual suspects.

Richard Davidson, a neuroscientist, explained how happiness is a skill that can be learned; public policy expert Robert Putnam showed the importance of social connections; economist Joseph Stiglitz highlighted the flaws with GDP; Buddhist monk Matthieu Ricard explained the reciprocal benefits of altruism; and Martin Seligman, founder of positive psychology, reminded everyone that there's much more to a flourishing life than just the absence of misery. How did a traditional economist start welcoming in such a rainbow of different views and traditions?

"I did not have this concept in my mind when I was younger," he says. "I was an economist and was asked go and solve a problem, trying to end hyper inflation in Bolivia, and I quickly realised that any real problem is so far beyond your own discipline.

"I found there are great answers around if you step outside your discipline but it is in compartments. One of my gurus is E O Wilson, one of the world's greatest thinkers. One of his concepts is concillience, which is the jumping together of knowledge and he propounded that not only the social and physical sciences, but humanities and arts, have to come together along with cultural and religious traditions.

"As we learn intellectually how to harness these linkages, we will be more effective at facing our most fundamental challenge which is wellbeing and sustainability of the planet."

As Sachs prepares to dash off for his next appointment, I ask him what has most surprised him in his search for wellbeing and happiness.

"I find the most wonderful part of what I do, travelling to more than 100 countries, is the common humanity and the ability to forge meaningful bonds across every divide one can imagine, whether intellectual or racial and religious. It is powerful and it is the common shared human nature and human fate that makes it possible to see these matters in a more holistic way."

This content is brought to you by Guardian Professional. Become a GSB member to get more stories like this direct to your inbox