April 11, 2011

Nitrogen Helps Feed World But Pollution Costly

The growing world population relies on the help of nitrogen for our food supply, yet its very use pollutes the air, soil and water.

The first European Nitrogen Assessment (ENA), launched at a conference today, estimates that nitrogen pollution will cost Europe an annual of &eur;70 to &eur;320 billion ($100-$460 billion USD) in damages.

It found that the nitrogen pollution contributes to climate change as well as biodiversity loss.

"Nearly, half the world's population depends on synthetic, nitrogen-based fertilizer for food but measures are not needed to reduce the impacts of nitrogen pollution," said lead editor Mark Sutton of U.K.'s Center for Ecology and Hydrology.

Robert Watson, chief scientist at Britain's ministry for environment, farming and rural affairs, says, "It is not about getting rid of fertilizers, it is how do we use fertilizers in a much more careful way through precision agriculture so we capture those benefits for agricultural productivity without having these negative effects."

Reuters reports that 80% of nitrogen emissions are caused by agriculture, with crops grown to feed livestock accounting for most of that.

200 experts from 21 countries and 89 organizations participated in a five-year study that found that this cost is more than doubled the extra income gained from using nitrogen fertilizers in European agriculture.

Nitrogen compounds produced through burning fossil fuels poses a greater threat to the environment, yet only account for 40% of the cost, according to the study.

Key notes found in the study include:

  • At least ten million people in Europe are potentially exposed to drinking water with nitrate concentrations above recommended levels.
  • Nitrates cause toxic algal blooms and dead zones in the sea, especially in the North, Adriatic and Baltic seas and along the coast of Brittany. 
  • Nitrogen-based air pollution from agriculture, industry and traffic in urban areas contributes to particulate matter air pollution, which is reducing life expectancy by several months across much of central Europe.
  • In the forests atmospheric nitrogen deposition has caused at least 10% loss of plant diversity over two-thirds of Europe.

Through this study, geographical areas that are affected most by nitrogen pollution are pinpointed, giving policymakers a complete scientific assessment of the costs of not addressing the issue. It also outlines certain actions that will protect the environment and public health as well as reduce the problem.

Sutton says, "Solutions include more efficient use of fertilizers and manures, and people choosing to eat less meat."

"Nitrogen is absolutely critical for human wellbeing but the challenge is how do we capture the benefits of nitrogen and minimize the adverse effects," Watson says.

He also says that "things are going in the right direction, what this (report) is saying is we need to go further to avoid this environmental damage."

According to Watson, nitrogen oxide emissions have dropped by 60% since 1990 in Britain and nitrogen fertilizer use dropped by 19% between 1998 and 2010.

For the first time, the ENA study evaluated the multiple threats of nitrogen pollution in economic terms at such a global scale.

The study will be discussed at a week-long conference held this week in Edinburgh, Scotland.


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