This issue’s cover posed a challenge: to present cannabis in a way that was recognisable, but that didn’t immediately call to mind a number of associations. An image of a cannabis leaf has layers of meaning attached to it. We wanted to make it possible for readers to take a fresh look. We are, as a nation, taking a fresh look at cannibis. Last year a survey found that nearly two-thirds of us didn’t have a problem with people using it for fun, and even more people thought it should be available for medical purposes. As with alcohol, we seem to be happy to leave the risk calculation up to the individual. (I think my dad summed up the views of those two-thirds of New Zealanders quite well: “You should be free to misuse your body however you like.”) In another survey, most people said that of all New Zealand’s environmental features, rivers and lakes were the worst-managed—and two-thirds of people believed dairy farming to be the culprit. In other words, we shouldn’t be free to misuse land however we like. We shouldn’t be allowed to spread certain substances on the nation’s pastures. Less management of cannabis, please, and more of freshwater. Our social views change slowly enough that the government ought to be able to keep up. On these issues, it hasn’t. As we begin to value things differently, the costs of them change, too. Since European settlers arrived in New Zealand, the nation’s waterways have been treated as a pre-fabricated sewage network—put it in the river, and the river carries it away. We don’t want to use our rivers in this manner anymore, but the primary sector has been caught by surprise at the change—not to mention the need to invent a brand-new nationwide nutrient-drainage system from scratch. As Kennedy Warne describes in his story on rivers, agriculture and environmental tipping points on page 36, a large group of scientists are working on this problem, but the solutions aren’t free or easy. Animal-derived foods cost more than the price we pay for them, and our waterways pay the difference. We can remove this cost from our lakes and rivers if we take it on ourselves, but the size of the issue means that it can’t be left to individual decision-making—regulation is required. Meanwhile, our other value change is looking better for the nation’s bottom line. Treasury has already done the maths on the revenue it stands to gain via GST and company taxes on legalised cannabis—and it’s in the hundreds of millions. Not to mention the potential savings to police of no longer enforcing prohibition. Costs, returns, values—it is a complex public equation, but I invite you to open this issue and make a fresh calculation with an open mind.