European Space Agency
THERE is an invisible gas in Earth’s atmosphere that is feeding an environmental crisis. The damage gets worse every year. If things are left unchecked, we are heading for a global disaster. And here is the most worrying thing about this gas: it isn’t carbon dioxide.
Nitrogen is normally thought of as inoffensive stuff; after all, this colourless substance makes up 78 per cent of Earth’s atmosphere. When you feel a refreshing breeze on your cheeks, it is mostly nitrogen molecules swishing past. Our ecosystems naturally cycle nitrogen from the air in and out of our soils, where it forms an essential nutrient for plants. The trouble is, this cycle is now dangerously out of whack because of human activity. The result is nitrogen in harmful forms swamping the wider environment.
Some of the effects of this crisis have been obvious for ages. We have long known, for instance, that pollution from nitrogen-bearing compounds prompts algal blooms that choke waterways. But other effects are now coming into focus too, like the way nitrogen pollution is killing peat bogs. Compounds of nitrogen are also damaging the delicate balance of the atmosphere.
A United Nations panel set up to assess the problem has revealed just how bad things have become. In fact, nitrogen pollution is one of the most dire crises we face. Fortunately, there are ways that we can dig ourselves out of this hole – but they will involve wholesale changes to how we grow our crops.
All life on Earth depends on nitrogen. Most of the crucial chemical components of our bodies, from the proteins in our nails…
