Johann Hari: Six good reasons for feeling cheerful

Reason to Roar Number Two: The hole in the ozone layer is beginning to heal

As a columnist, it's always easier to look out over the world's agonies and offer your readers reasons to be miserable. "Lots of people live free, happy lives today" is never much of a headline. So right now I could serve up a Boxing Day dish of global warming, nuclear proliferation, the implosion of Iraq, and the starvation of Africa with a sprig of parsley, and it would all be true and terrifying. But today - in our bloated post-Christmas glow - is a good day to remember that hope is the basis of all good leftish politics.

It's no coincidence that the most liberal American President of the 20th century - Franklin Roosevelt - declared "we have nothing to fear but fear itself", while his most conservative successor, George W Bush, seems determined to keep Americans in a constant state of amber-alert anxiety. So here is something I should do more often. Here is a bouquet of reasons to feel hope.

Prozac Pill Number One: Europe is free, democratic and at peace, from the shores of the Atlantic to the Ural mountains. When my grandparents were my age, they were scattered across a rubble-strewn continent that had consumed itself in fire twice in a generation, churning out more than 50 million corpses.

The Europe that emerged from the wreckage was divided by a giant concrete wall, with half of its citizens trapped under the Communist fist. To them, the idea that their grandson would live in a Europe with no dictators and no mass death would have seemed like sci-fi. If Europe, after a century of genocide and tyranny, can end up like this, we have some reason to hope for Africa and the Middle East too.

Reason to Roar Number Two: The hole in the ozone layer is beginning to heal. This was the environmental nightmare of my childhood, with CFCs trashing an essential part of the planet's protective layer. But determined political action by environmentalists managed to alert the world's people, who ignored the deniers and reacted rationally in their own self-defence by ditching CFCs. The observing stations of the American Geophysical Union have found that the depletion of ozone in the upper atmosphere has now slowed down, and will recover within a few generations. This shows that it is possible for the world's divided governments to deal with environmental threats in a sane way.

Of course, it will take a much bigger wrench for us to slash back the fossil fuels that are causing catastrophic global warming. The deniers are more determined and more drenched in corporate cash now, and we don't have a lot of time to defeat them. But the healing skies over the Arctic show it is possible.

Hip-Hip-Hurrah Number Three: Far more British teenagers trapped in poverty are staying on to get qualifications since the government introduced Educational Maintenance Allowances (EMAs). These are weekly payments of £30 to students from poor families who stay on to do A-levels or a GNVQ, with an annual bonus of £500 if they get good grades.

When I was at college, it used to be that the working-class students who could afford to stay in school had to work knackering minimum-wage jobs to be able to afford a good Saturday night out, while middle-class kids had much more time and energy to study (and got better grades as a result). Today, that's not the case. For all its flaws, that's a Labour government in action - while David Cameron's Tories dismiss it as "waste" and "a bribe". EMAs are a beautiful demonstration of how concerted government action can help the poorest people to lift themselves up, and make Britain a better, more equal country.

Joy! Number Four: The everyday miracle of science - the living embodiment of the Enlightenment - is continuing to find cures for diseases wherever it is not blocked by organised superstition. The list of life-saving, life-enhancing discoveries made by scientists this year could fill an entire issue of The Independent, but here's some choice cuts. Researchers in Toronto have managed to cure diabetes in mice, leading to hopes of a major breakthrough for humans in the next few years. The US National Federation for the Blind's team has invented a machine that can be held over printed text and read it out to blind people - an innovation that in time will be as important as guide dogs.

And - best of all - there is now a vaccine that prevents cervical cancer, a disease that kills more than 300,000 women worldwide every year. The Ministry of Health is poised to roll it out across Britain in 2007. Incredibly, the churches are opposing this, claiming cervical cancer is a "good deterrent" and that vaccinated kids will be more likely to have sex. Where scientific knowledge can be freely pursued, it saves millions from slow, painful deaths.

Slab of Chocolate Cake Number Five: Since 2002, 60 million people have been lifted out of poverty in China, matched by nearly 40 million in India. There are still terrible problems in both those countries - but it's worth pausing to realise what these statistics mean. That's 100 million more human beings who will not go to bed hungry tonight. That's 100 million more people who will live to an old age, and not bury their children because they were too poor to keep them alive. In the two most populous countries in the world, poverty is falling, and human happiness is rising.

Reason to Glug Champagne and Hug Children Number Six: Take That have reformed - and they're thrashing that whining narcissist Robbie Williams. Okay, so I admit the main reason we are all happy Take That are back (back, back for good) is that it has reawakened the adolescent fantasies of every British woman and gay man in their twenties. But it is also a shimmering sign that sometimes, just sometimes, the nice, quiet, talented people prevail over the brash exhibitionists.

For over a decade, Robbie has taunted the wholesome foursome who helped make him famous, calling Gary Barlow "fat" and laughing about their chart-flops. He paraded his naked ego at every opportunity, even becoming the only performer at Live8 who didn't mention Africa once. ("I've had a really tough year," he announced instead. I'm guessing it wasn't as tough as the kids in Sierra Leone, Robbie.) But now Take That are back with a million love songs and a bashfully surprised smile at their mega-success, and Robbie is languishing with nothing but his own self-obsession as comfort.

Yes, there are reasons to be depressed and scared, and I will probably be talking a lot about them in 2007. But just for today, let's hum along with Louis Armstrong: "I hear babies cryin', I watch them grow/ They'll learn much more than I'll ever know/ And I think to myself, what a wonderful world."

j.hari@independent.co.uk