Call to tackle nitrogen's multi-pronged threats
The threat of global warming has stamped 'carbon' into the world's consciousness, as well as the pages of its dictionaries. We worry about our carbon footprint, aim to cut our carbon emissions, decarb our lifestyles - and even have a whole new generation of carbon accountants tracking man's meddling in the carbon cycle. But carbon isn't the only natural cycle we have messed with. Nitrogen is another key part of the planet's chemistry, whose normal flow has been seriously disrupted by man. And it's also one that has very much been overlooked, in the focus on carbon.
Biggest disaster that no-one has heard of
But with nitrogen playing a massive role in the biological and climatic meanderings of the planet, we need to pay much more attention to our nitrogen-related emissions - and to scale up efforts to reduce their impact on the planet. "It's been said that nitrogen pollution is the biggest environmental disaster that nobody has heard of," said Alan Townsend, from the University of Colorado. He was speaking at this week's nitrogen-themed presentation at the 242nd National Meeting & Exposition of the American Chemical Society (ACS).
Nitrogen is weaved into many aspects of the planet's environmental woes. It plays a role as a planet-warming greenhouse gas, when in the form of nitrous oxides. Its presence helps the formation of ozone, a big health-hazard in many cities. As nitrates in rivers and the sea, it can power massive toxic algal-blooms and oceanic dead zones, as well as polluting drinking water. But it can also form sunlight reflecting aerosols which help to cool the planet.
"A single atom of reactive nitrogen can contribute to air pollution, climate change, ecosystem degradation and several human health concerns," Townsend said. And the origin of all that problem-causing nitrogen? It can be tracked, in the main, to two activities underpinning the modern world - the burning of fossil fuels to feed our massively increased energy consumption, and the ladling of millions of tons of fertilizers onto soils, to feed an ever-swelling human population.
Getting clever with nitrogen
The papers being presented at the ACS exposition are more than doom and gloom, however. As well as describing the scale and impact of humans on the nitrogen cycle, they explore some promising approaches for reducing our nitrogen-offloading habits. That includes measures to strip nitrogen from the smokestacks of fossil fuel-burning plants, becoming much cleverer with the control and application of nitrogen fertilizers, and shifting towards more organic methods of food production.
"We're just now starting to recognize the scope of the problem," said Townsend. "But the good news is that there are many opportunities for us to lessen the problems. These include ways in which chemists can help, ranging from the development of new technologies to reduce nitrogen's impact to new measurement technologies and techniques that can better diagnose the problems we face with nitrogen."
But Townsend also concedes that the nitrogen challenge - as is also remarked about for dealing with carbon emissions - is not so much a technical one, but more a question of the will to change things for the better. "In many ways, we already know how to do it - the problems are largely about finding the political and cultural means to implement these new practices," he said.
Top Image Credit: Fertlizing © Isteo