Is the nitrogen cycle out of whack?

When it comes to fossil fuel emissions, carbon dioxide currently has center stage. But humans are also adding nitrogen to the environment. And it's happening at an alarming rate. We need nitrogen to produce food and energy. But we're too inefficient about it, say researchers reporting in Science magazine today.

Humans are adding nitrogen both by burning fossil fuels and by its use in agriculture and industry. And now, the nitrogen cycle is out of whack. Too much reactive nitrogen is starting to accumulate in soil, water, the atmosphere and the oceans.

That extra reactive nitrogen contributes to all sorts of environmental problems — smog, haze, "dead zones" in the coastal ocean, the greenhouse effect and ozone depletion. To balance the cycle, we need to manage our nitrogen use better, the scientists say. Controlling nitrogen emissions from fossil fuels will help. And other solutions are better treatment of sewage, and finding ways for crops to get more nitrogen out of their fertilizer.

Carolyn Gramling

Back to top