Every single year the marine industry burns enough oil to flood the entire Island of Manhattan to 7m in depth, that's enough to entirely cover a two-story house.

The IMF recently calculated global implicit and explicit subsidies on fossil fuel production to be $5.9 trillion. Looking just at oil based products, this would imply an approximate subsidy of $1100/tonne. This puts the subsidy for Shipping's oil usage at $376 Billion, every year.

HFO is so toxic, it is banned as a fuel source for ships travelling in the Antarctic, to prevent a spillage devastating the protected environment. Sadly it is still used by 60% of the approximately 60,000 "large" vessels in the world - with that percentage likely to increase as fuel prices climb.

Those living near ports and high marine traffic routes are most at risk. Having high population density in general, it's no surprise to see 6 of the worst affected countries located in the European continent.

The high illness and death toll is caused by emissions from shipping being far higher in cancer, pulmonary and cardiovascular disease-causing chemicals than road transport. As one example, it has been shown that the 16 largest cargo vessels emit as much toxic sulphur (in the form SO_x) as 800 million cars.

The mix of emissions include several toxic irritants as well as various particulate matters. Together these have a substantial affect on lung health, and beyond premature death can lead to various illnesses - as another example, shipping has been directly linked with causing up to 6.4 million cases of childhood asthma globally every year.

If Shipping was a country, it would be the 6th highest emitter of CO2 in the world, ahead of Germany, Mexico and the United Kingdom

The over 1 billion tons of emissions does not account for the CO₂ used in sourcing, refining and transporting the oil, which could add a further 11% (another 110 000 000+ tons) according to detailed studies.

If shipping emissions continue to grow as projected (and allowed by IMO targets), the maritime industry will single handidly undermine the objectives of the Paris Climate Agreement.

Long-term exposure to high levels of nitrogen dioxide can cause chronic lung disease, worsen asthma and heart disease and is tied to elevated risks of premature death. Only one or two breaths of a very high concentration can cause severe toxicity.

In the presence of rain, nitrogen oxides form nitric acid, creating acid rain – killing trees and plant life, and destroying marine ecosystems.  High levels of nitrogen dioxide are also responsible for damaging plant growth/reducing crop yields.

While only 2% of total shipping emissions, NO_x is estimated to have a Global Warming Potential of over 30 times greater than CO₂. This would make the NO_X emissions from shipping almost as disastrous for climate change as its CO₂ emissions.

Scrubber systems use seawater spray to remove some of the contaminants from the engine’s exhaust, dumping the acidic wash into the ocean. It’s estimated by the International Council on Clean Transportation (ICCT) that 10 billion tonnes of scrubber washwater is discharged into the oceans annually – causing acidification and destruction to the marine environment.

High oil prices are causing shipping operators to ditch Very Low Sulfur Fuel Oils in favour of cheaper High Sulfur Fuel Oil, which can have a sulfur content of up to 3.5%, in combination with scrubbers, which will lead to an increase in ocean acidification and atmospheric SO_x emissions.

Just like NOX, SO_x is extremely hazardous to the environment and human health. In humans long term exposure can cause respiratory diseases, high concentrations can cause death in a single exposure. It is also a suspected mutagen. For the environment it causes acid rain and acidification of the oceans.

Methane emissions are considered such a risk, that several initiatives have launched satellites into space to better understand emissions sources and how we can control them. While agriculture is currently the biggest offender for methane emissions, the approximately 45 mega tonnes produced by the oil industry are seen as an easier target to fix with regulation and controls.

Methane is also the primary contributor to the formation of ground-level (tropospheric) ozone (O₃) or smog, by mixing with NO_x and Volatile Organic Compounds (VOCs - also heavily emitted by shipping). Ground level O₃ is a hazardous air pollutant and greenhouse gas, exposure to which causes 1 million premature deaths every year.

LNG is currently being explored as another alternative to HFO for shipping – however “fugitive” methane emissions and methane “slip”- where methane escapes storage reservoirs unintentionally or passes through the engine un-combusted - are a big risk, and are currently under the scrutiny of several studies.

N₂O is currently the single most ozone-depleting emission and is expected to remain so throughout the 21st century, and could well reverse the good work of the Montreal Protocol that has helped restore the ozone layer's protective effects.

Nitrous oxide emissions from human activities have increased 30 percent over the past four decades, surpassing the highest emission levels scientists have projected in climate models. Most of this increase has come from agriculture or natural sources, however given its severity, the approximate 0.5% that can be attributed to shipping is still significant.

With the pending climate crisis, other fuel sources are being considered. One of these is Ammonia, which amongst a litany of issues, produces large amounts of N₂O during combustion, and would require scrubber style systems to have it removed from the exhaust gas – introducing large amounts of N₂O into the marine environment.