The United Nations has released another report, Global Environmental Outlook 4 [pdf], on the state of our planet’s ability to support life, yet it has received minimal coverage. Our news media should explain why. Read the below summary of the report (courtesy George Monbiot), and try and imagine what else could be of more importance.

Crop production has improved over the past 20 years (from 1.8 tonnes per hectare in the 1980s to 2.5 tonnes today), but it has not kept up with population. “World cereal production per person peaked in the 1980s, and has since slowly decreased.” There will be roughly 9 billion people by 2050: feeding them and meeting the millennium development goal on hunger (halving the proportion of hungry people) would require a doubling of world food production. Unless we cut waste, overeating, biofuels and the consumption of meat, total demand for cereal crops could rise to three times the current level.

There are two limiting factors. One, mentioned only in passing in the report, is phosphate: it is not clear where future reserves might lie. The more immediate problem is water. “Meeting the Millennium Development Goal on hunger will require doubling of water use by crops by 2050.” Where will it come from? ‘Water scarcity is already acute in many regions, and farming already takes the lion’s share of water withdrawn from streams and groundwater.” One-tenth of the world’s major rivers no longer reach the sea all round the year.

Buried on page 148, I found this statement. “If present trends continue, 1.8 billion people will be living in countries or regions with absolute water scarcity by 2025, and two thirds of the world population could be subject to water stress.” Wastage and deforestation are partly to blame, but the biggest cause of the coming droughts is climate change. Rainfall will decline most in the places in greatest need of water. So how, unless we engineer a sudden decline in carbon emissions, is the world to be fed? How, in many countries, will we prevent the social collapse that failure will cause?

The stone drops into the pond and a second later it is smooth again. You will turn the page and carry on with your life. Last week we learnt that climate change could eliminate half the world’s species; that 25 primate species are already slipping into extinction; that biological repositories of carbon are beginning to release it, decades ahead of schedule. But everyone is watching and waiting for everyone else to move. The unspoken universal thought is this: “if it were really so serious, surely someone would do something?”

When a crowd of people watches something bad happen, the likelihood that someone will intervene to prevent it decreases as the size of the crowd increases. And here we are, the whole human race, watching our planet’s ability to sustain our lives slip away, waiting for someone to act.

Politicians, bloggers, voters: no more games please. This is issue number one. As the most unlikely of newspapers (The Toronto Sun) declared last week, we’re at red alert. The time to hesitate is long past through, and half-measures are not going to cut it.