The appreciation for natural resources as a driver of economic development has undergone a dramatic change in the past decades. Although an abundance of resources was generally perceived as advantageous until the 1980s, an influential literature emerged in the 1990s that reached seemingly opposite conclusions. The phrase "natural resource curse" was coined and, perhaps because of its paradoxical connotation, caught on in both academic and policy circles.

In a recent perspective, "Food security under climate change" (1 February, P. 580), M.E. Brown and C.C. Funk conclude that improved seed, fertilizer, land use and governance lead to food security. I find these claims highly questionable. The green revolution model (monocultures of improved crops supported through high levels of agrochemical and other inputs) has done much to increase agricultural productivity. It does little, if anything, to increase food security. (Letters)

A new paper shows that regional and even global temperatures are being temporarily held down by a natural jostling of the climate system, driven in large part by vacillating ocean currents.

Oxygen-poor waters occupy large volumes of the intermediate-depth eastern tropical oceans. Oxygen-poor conditions have far-reaching impacts on ecosystems because important mobile microorganisms avoid or cannot survive in hypoxic zones. Climate models predict declines in oceanic dissolved oxygen produced by global warming. The researchers constructed a 50-year time series of dissolved-oxygen concentration for select tropical oceanic regions by augmenting a historical database with recent measurements.

If there is an example of a silver bullet among genetically modified (GM) crops, it would be virus-resistant papaya trees. They saved the papaya industry in Hawaii from devastation by the ringspot virus, a serious pathogen that deforms fruit and eventually kills conventional trees.

It was supposed to prevent blindness and death from vitamin A deficiency in millions of children. But almost a decade after its invention, golden rice is still stuck in the lab.

Atmospheric measurements show that the carbon dioxide (CO2) concentration in the atmosphere is currently '385 parts per million (ppm) and rising fast. But this value is a global average that tells us nothing about the regional distribution of greenhouse gas emissions. As the world embraces myriad mitigation strategies, it must gauge which strategies work and which do not. Gaining such understanding will require a greenhouse gas monitoring system with enough accuracy and precision to quantify objectively the progress in reducing emissions.

More than a billion acres have been planted with genetically engineered crops in the USA since 1996, but we do not fully know their ecological costs and benefits.

The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming the Arctic, and fluctuations of regional fresh water inflow into the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence.

Demand for plant products has never been greater, more people, rising affluence, and expanding biofuels programs are rapidly pushing up the prices of grain and edible oil. Boosting supply isn't easy: All the best farm land is already in use. There's an acute need for another jump in global agricultural productivity-a second Green Revolution. Can it happen? Will it happen? (Editorial)