By Alex Kirby BBC News Online environment correspondent

The proportion of really poor people in the world is gradually falling, as development spreads outwards. But the world's population is still growing, and the rate of progress is too slow to tolerate.

Average life expectancy

When I worked in one of the world's poorest countries, Burkina Faso, 30 years ago, average life expectancy was about 42 years. Today it has improved to a little more than 47 years, a snail's pace that challenges everyone who lives in plenty.

We have scant hope of meeting the Millennium Development Goals, and we are all the losers. Ignore the morality if you want. The wretched of the Earth have so little to lose they may not hesitate to destroy what we have. And they have no choice but to destroy their share of the one environment which sustains us all.

Listening to the voices of the poor

So we have a direct interest in knowing the facts about development. If we cannot hear the voices of the poor themselves, let us listen to those who work alongside them.

I know of no development "industry": there may be a very few people making good livings off the backs of the poor, but almost every professional I have met does it from conviction, not for gain. I am as sceptical of what they tell me as I am of what I hear from politicians and archbishops, but that is because scepticism is the air reporters breathe. Anyway, my scepticism usually turns to admiration for lives of quiet heroism.

Spotlight on one particular issue

Sometimes we turn the spotlight on one issue and neglect others just as cruel and urgent. HIV/Aids is sexier than diarrhoea, but kills fewer people. But we should not blame the public relations teams. We know what will sell. We demand the pictures that show starvation so vividly and ignore the corrosive effects of malnutrition that are impossible to picture.

The only reason I ever wanted to be a journalist was to help people to understand their world better so they would change it. Often it does not happen. But I do remember one of the first stories I filed to Reuters from Ouagadougou in my Burkina Faso days.

I reported how there was not enough foreign help to enable many starving people to survive the savage Sahel drought. Several months later, the source of my story told me it had led some governments to change their policies. We need to know all we can.