The answer to the impact of air pollution lies in ... the deep blue sea

IMAGINE for a moment standing on a sun-soaked beach, the surf crashing against the shore, and inhaling the salty, moist sea air. It’s invigorating.

- DR KATYE ALTIERI

But is it really? Hundreds of years ago, perhaps, but what about now? How do the ocean and the air interact in the presence of human-created air pollution, specifically nitrogen, and how does this relationship impact climate change?

The simple truth is, we don't know - and I want to find out.

Our oceans are as important to life on Earth as the air we breathe. An enormous carbon sink, they help to remove the greenhouse gas carbon dioxide (CO2) from the atmosphere, which is of course a good thing.

As a matter of fact, nitrogen helps the oceans to remove CO2 from the atmosphere. The problem is, too much of it can spur the production and release of nitrous oxide (N2O), another greenhouse gas that is 300 times as potent as CO2. That is clearly not a good thing.

As with everything in nature, things work when there's a balance; invariably, however, we humans throw out that equilibrium through our activities. That's why we're struggling so much with the issue of climate change, so much of which has to do with the pollution of our atmosphere.

We have doubled the amount of nitrogen in the atmosphere through activities such as fossil fuel combustion and agriculture. That nitrogen, even from far inland, is swept out to sea and settles in the ocean.

But we don't know exactly how much pollution-derived nitrogen reaches the open ocean. We don't know exactly what happens when it settles in the ocean.

And we face a conundrum: does it increase the ocean's ability to remove greenhouse gases from the atmosphere, or emit more deleterious greenhouse gases into the atmosphere?