Imagine the world of civil society in 20 years' time. What will charities and voluntary organisations look like? Will the voluntary sector be dominated by a handful of multinational mega brands? Will faith organisations or trade unions be booming? Will public services have been taken over by big social enterprises, with chief executives on £1m salaries? Will the 2020s equivalents of MySpace and Facebook have created a generation familiar with instant activism, or a generation of solipsistic couch potatoes? Will responses to the pressures of climate change - carbon taxes, the end of cheap air travel, and the revival of local sourcing of food - have catalysed a dramatic strengthening of local communities?
Over the last eight months, the Carnegie UK Trust's inquiry into the future of civil society has been exploring where we might be headed. We've used a range of forecasting and scenario methods, techniques which are now widely used by the business community and public sector. These helped shape dozens of meetings that gathered insights from hundreds of people working in and around civil society in all its forms, and reflected the lively diversity of post-devolution UK and Ireland.

Fuzzy boundaries

The science fiction writer William Gibson famously said that the future is here already, just distributed unevenly. Certainly we've discovered it is possible to see today some of the trends that may transform civil society. Globalisation is already having a very visible impact - and not just through big events like Live8, but also through diaspora migrant communities acting as channels for aid and campaigns as well as remittances back to their countries of origin. Technology is another very visible driver of change and has already made it far easier to organise people, whether on local or global issues. Some of the household names of 20 years time look likely to be web-based civic organisations - though there are also well-grounded fears that the internet could become much more commercialised and inaccessible.

An ageing population could be another boon for civil society, providing an ever larger pool of people with time and energy for civic life. But there are unanswered questions over whether the third sector will provide the greatly expanded elder care that's likely to be needed over the next few decades, or whether the public sector and private providers will turn out to have an edge. Equally, although civil society has played a decisive role in putting climate change on the public agenda, it's less clear whether the heavy lifting to change lifestyles over the next few decades will be done more by civil society or by government policy - carbon taxes and regulations - and big business.

The meetings aired anxieties about civil society's relationships and often fuzzy boundaries. Big business increasingly likes to portray itself as socially concerned, adopting the style of civic action through "campaigns" of varying degrees of cynicism. Make Poverty History was just one example of many of the virtues - and risks - of very close relationships between NGOs and governments, and the tightrope many have to walk in combining influence on the inside with campaigning from outside.

But one theme came through more strongly than any other. This was the concern that for all the strength of civil society, and the burgeoning numbers of charities, social enterprises and voluntary organisations, we may be witnessing a more basic fragmentation of our society and a disconnect between people, classes and races that could grow worse over the next few decades. One aspect of this is the widening gulf between rich and poor, with the top 1% living ever more rarefied lives, and the very poor ever more marginalised from political power as well as from economic opportunities.

It's an irony that growing inequality could mean more money for philanthropy. In the US, quite a few of the ultra-rich have taken to heart the 19th century industrialist and philanthropist Andrew Carnegie's comment that it's a disgrace to die wealthy. So far, however, little of the money accumulated by the top 1% during the longest boom in British history has yet found its way into social causes. Many hope that this will change. But others are ambivalent about what this could mean - especially the risks of rich people exercising even more power over poor communities.

In some places fears of disconnection focused on culture and race. Even if some of the more lurid claims about widening segregation have been overplayed, there are plenty of areas where there's remarkably little mixing across class and racial boundaries. There were also concerns about declining civility and mutual respect. One effect of an individualistic culture that's poor at instilling mutual respect is that people jump more quickly to anger or violence. Declining levels of social trust have certainly left British children - and their parents - less trusting of both their peers and strangers, and less likely to commit to civic causes.

This concern related to fears that we might be losing the shared public arenas where communities can deliberate about the future. Newspapers and broadcasters have fewer resources for investigation and news, as opposed to comment. Politics and political parties have been hollowed out by a generation of centralisation and diminishing public interest. The web has turned out to be much better as a tool for mobilising communities of interest than for community-wide deliberations. The net result may be a loss of our collective ability to build bridges across social divides or to resolve conflicts when they arise.

Increasing fears

For the inquiry's international advisers the biggest concern was that fear itself would corrode civic life. Tighter security legislation is already hampering peaceful protest and, looking ahead, both terrorism, and increasing fears about terrorism, could sow distrust between communities. At a global level, the stringent security laws introduced in Europe and America are already being used to justify authoritarian regimes stamping even harder on their own dissenters.

There were several dogs that didn't bark. There was much less discussion about the role of the third sector in delivering public services than we expected. Most people assume there will be modest expansion in third sector provision - but it was seen as equally likely that the private sector will displace existing third sector providers. Nor was there much discussion about the independence of the sector. As the recent Centris report prepared for the inquiry confirmed, few civil society organisations see this as a pressing issue.

So is civil society prepared for the future? Probably not. Most organisations have to live hand to mouth, juggling short-term funding and perpetual minor crises. Even the bigger ones rarely get much time to stand back and look at the bigger picture. Many are on a treadmill chasing after contracts and new funding.

The French futurist Gaston Berger once said that the purpose of looking to the future is to disturb the present. It's only by being disturbed that we stand a better chance of shaping the future rather than being its victims.

· Geoff Mulgan is chair of the Carnegie UK Trust inquiry into the future of civil society in the UK and Ireland. More on the inquiry and its reports at carnegieuktrust.org.uk

Everyone with a good idea wants it to have an impact, but what turns promising social innovations into household names? What made microcredit, distance learning and street papers succeed while other good ideas languished?
In a Young Foundation study, published today, we surveyed what has been learned around the world about "scaling up", and we have completed a series of detailed case studies on examples ranging from Alcoholics Anonymous to Sure Start, Teach First to the Big Issue.

Our findings confirm that it's never enough to "build a better mousetrap". Having a good idea won't guarantee that the world beats a path to your door. Innovators need to cultivate "effective demand" from people or institutions with the money to pay for it. That might be thousands of consumers, as in the case of fair trade, or a government department, as with new models of schooling. The key point is that often innovators have to be advocates and campaigners too.

Innovators also have to work on "effective supply", turning a promising idea into something that is really productive. This usually involves hard graft, testing, refining and adapting the idea. Sometimes it means investing scarce resources in trials and pilots, as Education Extra did for extended schooling, and sometimes it simply becomes clear that the idea isn't replicable. Everyone knows of great projects that were too dependent on a charismatic individual, or simply too expensive to be replicated.

Spreading an idea is hard work. The phone-based language translation service, Language Line, failed to spread to Germany partly because policy makers there thought that migrants should learn German. The Big Issue was rebuffed in California, and not only because people there generally drive to work rather than walk .

Our bigger message is that replication doesn't just depend on growing organisations. Bigness has become fashionable in the social enterprise world, partly due to the influence of business. But most organisations built around a social innovation find it hard to grow, and not just because of lack of capital. Growth often requires organisations to change their culture, becoming more formal, as well as their leaders - since founders' virtues can become vices when growth is under way - and their accountability arrangements. Nor are the halfway houses between organisational growth and loose diffusion - franchising, licensing and federations - any easier to pull off.

A key message in our report is that, in practice, most social innovations spread through influence and copying, rather than through growing the social equivalents of Microsoft or BP. It's true that radical ideas are often best promoted through the example of real organisations. But their impact comes from movements for change that far transcend the organisations that first put them into practice.