1. It's Carers Week. About 6.5 million Britons are unpaid carers. And that number is going to go up and up. ONS / BuzzFeed / Via ons.gov.uk That's 6.5 million people who give an hour or more of their time, for free, to look after someone else, usually a family member. Britain is going to face a crisis in the next few years: There are simply going to be too many people in need of care and not enough people to look after them. 2. Here's why. The population of the UK is going up. BuzzFeed / ONS / Via ons.gov.uk It was a little over 62 million five years ago; it's almost 65 million now. And by 2035, it's projected to be around 73 million. 3. In one sense, that's not an urgent problem. There's still plenty of room for everyone to live. ONS / BuzzFeed / Via gov.uk Less than 10% of Britain is built on. Large areas around 14 major urban centres are protected by green belts, and there about 29% of the rest of the land falls into national parks, areas of outstanding natural beauty, or sites of special scientific interest. But there're lots of places to build houses for more people to live in (although that isn't happening fast enough). 4. The reason we do need to worry about it is that as the population grows, it's getting older. ONS / BuzzFeed / Via ons.gov.uk The median age of the population was 39.7 years in 2010; by 2020 it's expected to be 39.9, and by 2035 it'll be 42.2. 5. What that means is that there will be more and more older people as a proportion of the population. ONS / BuzzFeed / Via ons.gov.uk Five years ago, there were almost four working adults for every one person above the (current) retirement age of 65. Now it's more like two and a half. The government has changed the retirement age so younger people will now have to work until they're 68, but even taking that into account, the Office for National Statistics (ONS) says "the number of people of state pension age (SPA) is projected to increase by 28 per cent from 12.2 million to 15.6 million by 2035".That's a problem for a variety of reasons – most obviously, it'll be harder to pay for state pensions with the taxes of working people. 6. And that means lots more people are going to have to become carers, because older people are disproportionately likely to require care. The Alzheimers Society / Via alzheimers.org.uk Two-thirds of dementia sufferers live at home, and most of those are looked after by unpaid carers. The number of people with dementia was about 850,000 in 2013. That figure is predicted to go up 40% by 2025, and 156% by 2051.And, of course, dementia is just one of the problems which strike older people more than younger people. 7. The Carers Trust estimates that an extra 3.4 million carers will be needed by 2040. ONS / World Bank / Carers Trust / BuzzFeed / Via carers.org That's an increase of around 60% from its 2010 estimate of 7 million (a little higher than the Carers Week estimate). In the same time, the ONS estimates that the population as a whole will have grown by just 18%. 8. And that comes at a cost. Carers are more likely to suffer from ill health… ONS / BuzzFeed / Via ons.gov.uk 9. …and less likely to be in work. ONS / Carers Trust / BuzzFeed / Via carers.org Comparing the ONS estimate of the employment rate of the population as a whole with the Carers Trust stats on employment of carers.The Carers Trust says that more than half of carers who are not in work say they would like to be. It says that "£5.3 billion a year has been wiped off the economy". 10. The burden of caring falls disproportionately on women… ONS / BuzzFeed / Via ons.gov.uk 11. …and young people suffer a lot too. University of Nottingham / BuzzFeed / Via bbc.co.uk A 2010 survey estimated that there are 700,000 young carers in Britain, and they're twice as likely to be "not in education, employment or training" (NEET). If that stat is right, it means that one young person in 12 is caring for a loved one. This isn't a problem that's going to go away.