Thread by @newscientist

All life on Earth depends on nitrogen, but because of human activity, the nitrogen cycle is now dangerously out of whack. Here are five ways that nitrogen pollution is harming our planet. (Thread...)

1. Rain can wash nitrates into watercourses and oceans. This nitrogen-based pollution feeds algal blooms that suck up oxygen as they decompose, choking aquatic life.

2. Cars and power plants emit nitrogen oxides, which are one of the principal precursors to a type of air pollution called particulate matter. These tiny particles can be breathed into our lungs, where they cause tissue damage associated with a range of health problems.

3. The same nitrate that can sneak into waterways can also pull key nutrients out of the soil, including magnesium and calcium. This can make soil too acidic, such that plants are unable to take up nutrients properly.

4. Rising levels of ammonia pollution are decreasing the acidity of the air. Certain habitats, such as peat bogs, rely on the air being slightly acidic. In Northern Ireland, this problem is causing the degradation of sphagnum peat moss bogs, a major store of carbon dioxide.

5. Excess nitrate can be converted by bacteria into nitrous oxide gas. At high altitudes, this reacts with ultraviolet light and eats away at the ozone layer that shields us from UV rays. The damage is tough to undo, because nitrous oxide has a lifespan of 120 years.

Fortunately, there are ways that we can tackle this forgotten environmental crisis – but they will involve wholesale changes to how we grow our crops. Read the in-depth report by @ajzaleski in this week’s New Scientist to find out more. newscientist.com/article/mg2503…