Only the heavens can prevent a dreadful drought in England Water companies have got much better since 1976 at safeguarding domestic supplies, so farmers are likely to feel the impact first - and much attention will be devoted at Monday's summit on trying to minimise the effect on producing food. "It is extremely worrying," Peter Kendall, the President of the National Farmers Union told me this week. I have been walking along the dry bottom of the major drainage ditches on my farm in December and January: I have never done that before in my life. Even bleaker months seem to lie ahead. Many farmers have long insured against dry spells by digging small reservoirs on their land, which they fill from nearby rivers over the winter. But river flows are so low that they have often been prevented from doing so this year: the Environment Agency is restricting 345 abstractions in order to safeguard supplies for other users and wildlife. Those who take water from rivers directly in the summer are expected to face similar impediments, as are those who rely on groundwater. The agency is helping by extending the season during which abstractions can take place. And farmers can make the most of their water by irrigating at night, to reduce evaporation, and avoiding windy days which blow the spray away. Some are also looking at planting crops that need less water, but room for manoeuvre is limited, not least because many are contracted to supermarkets to supply certain produce at particular times. Harvests are likely to suffer as a consequence, driving up food prices. Indeed, the crisis is expected to be so severe that households are likely to be affected too. Already appeals are going out to customers to save water by "rediscovering the joys of washing up by hand." And water companies are warning that hosepipe bans are likely before the summer. Demands for a national water grid are bound to resurface, boosted by the fact that, even now, the north and west of the country have plenty of water (Scotland has received the heaviest rainfall on record), and by projections that the disparity is likely to increase with global warming. But water is immensely heavy - we each use a ton a week - and very costly to move long distances. Tackling waste would help. Despite improvements in mending leaking pipes, almost a quarter of the water dispatched to consumers still never reaches them - and a third of what does is wasted. Using the planning system to discourage development in water-scarce areas would also be a good idea - if the Government did not seem so intent on weakening it. But none of this will help us this year; only massive, sustained rainfall can do that. Perhaps we should hope, given my record, that writing this article will do the trick. Can you really chew and concentrate? Think again It is an annoying habit that's often banned in schools, but new research suggests that chewing gum actually improves students" performance. Scientists at St Lawrence University, New York state, have found that indulging in it before tests bestows "multiple advantages" in boosting brainpower. More than 200 students were split into three groups. One chewed away for five minutes before taking "a battery of cognitive tests" and then stopped; the second kept going; and the third abstained. The first group did much better than the third under a range of measurements including for "working memory, episodic memory, and general speed of information-processing." The researchers put this down to "mastication-induced arousal." In other words, the jaw movements increase the heart rate and blood pressure, sending more blood to the brain. The benefit was greatest immediately after the chewing, and dropped to nothing over the following 20 minutes. Perhaps the thing to do, then, is to carry on masticating. Well no, according to the research. The students that kept going did no better than the abstainers - something the university's assistant professor of psychiatry, Serge Onyper, who carried out the study, attributes to "a sharing of resources by cognitive and masticatory processes." Or, put simply, it's not possible to chew gum and think productively at the same time. Good news about hot air No one seems to have noticed in Britain, but this week witnessed the most promising action on climate change in years. On Thursday, the US and five other governments launched a five-year programme to address pollutants such as soot, methane and hydrofluorocarbons, which together are almost as important as carbon dioxide in increasing global warming. While the international climate negotiations, which are focused on CO₂, crawl along, these pollutants can be cut rapidly by local and national governments using existing laws and technologies. There is an immediate effect; unlike CO₂, which stays in the atmosphere for at least a century, they disappear in years, sometimes days. Studies show that a series of uncomplicated clean-up measures would buy decades of time for tackling dangerous climate change. Even more important, they would save 2.4 million lives a year from breathing in the soot, which is mainly emitted by diesel engines and the inefficient cookstoves used by many of the world's poorest people. Prominent climate sceptics - such as Senator James Inhofe, who pioneered the Republican rejection of action on CO₂ - support an assault on soot. And Canada - which recently courted international outrage by quitting the Kyoto Protocol - is one of America's partners in the programme, along with Sweden, Mexico, Ghana, Bangladesh and the UN Environment Programme. Perhaps the world should have acted on these pollutants first, before addressing CO₂. Still, as they say, better late than never.