Nice brain teasers to keep you busy at the beach or while hiking in the mountains, or touring on your bike.
Han Lindeboom, endoument professor of Marine Ecology
'The Dutch Nobel laureate Paul Crutzen has claimed that we are living in the Anthropocene epoch. There isn't a place on earth you won't find some evidence of human influence and many global systems are now influenced or even dominated by humans. Researchers such as Marten Scheffer and Terry Hughes have taught us a lot about tipping points, where a certain limit is reached and you tip over into a completely different system. That principle applies to the climate and CO2. Perhaps we've already reached, or will be unable to avoid reaching, such a tipping point with CO2. In any case, it's clear that the rapidly growing world population is the root of the problem. Why don't we try to stop that growth by limiting people to one child per person (two for a couple) and accepting that as the norm?'
Harry Wichers, professor of Immunomodulation by food
'I am rather amazed by the energy policy in our country. Although I'm a climate change sceptic, I believe an alternative energy policy is highly desirable for other reasons besides the climate, if only to increase our independence from dubious regimes in the Middle-East or highly unpleasant pseudo-Tsars. It amazes me that we seem unable to come to a clear decision on which type of alternative energy is most suited to our situation. Why are our efforts divided and why are we lagging behind the rest of Europe? Might that be because Shell determines energy policy here?'
Prem Bindraban, former director of the world data centre for soils ISRIC, just started as director of the Virtual Fertilizer Research Centre in Washington
'Nutrients from (artificial) fertilizers are going to be essential if we are to produce enough food to feed 7, and soon 9, billion people. We're going to need innovative solutions and approaches to fertilizer if we are to reach food and environmental targets. Fertilizers are mined (phosphate, potassium) or produced in factories (nitrogen) and subsequently added to the soil. This process means that right off the bat 30 to 70 percent of the fertilizer doesn't benefit the plants and goes to waste. After they've been consumed by humans and animals, the fertilizer in plants end up in the environment as well. But the only place we want the fertilizer to be is in the plant! Why do the nutrients from the fertilizers have to be absorbed through the roots? If the nutrients are only assimilated into the biochemical process when they reach the leaves, can't we have the leaves absorb some of them directly? Or attach a drip to the trunk of a (fruit) tree? Or, if it does have to go through the roots, which properties of the plants or soil organisms in question can increase the efficiency with which fertilizer is absorbed? A lot of attention has been paid to reclaiming fertilizer, and rightly so. Couldn't we try to capture nitrogen from the air and apply it precisely and directly where it's needed?'
Herman Eijsackers, chairman of the Scientific Advisory Board for Wageningen UR
'The most challenging issue as far as I'm concerned is how to carry out science for impact without being accused of getting into bed with big industry. It's remarkable that the universities of Delft, Eindhoven, and Twente are able to work together with the industrial sector at least as intensively as we do without getting embroiled in the same kind of public debates. Perhaps that's because the research we do in Wageningen impacts people more personally, through their food, environment, and general well-being. That's why I believe Wagneningen needs to find a way to work together with citizens as well as industry and policy makers. But how do you do that?'