- Cutting ships’ average speed could reduce noise levels by 66 per cent
- A 20 per cent cut in speed could see relative CO2 levels drop by 24 per cent
- The shipping industry produced about 3 per cent of greenhouse gas emissions
Speed reductions across all shipping can lead to significant reduction in fuel consumption and in turn a reduction in CO2 emissions, the study claims (stock image)
Global shipping is thought to generate just over 3 per cent of the total greenhouse gas emissions produced
Air pollution comes from burning fossil fuels, cars, cement making and agriculture
The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change. Pictured: air pollution over Paris in 2019.
Ocean ships should have speed limits to reduce the amount of pollution they produce and cut the risk of them crashing into whales, according to campaigners.
A 20 per cent drop in the average speed of ships could reduce the amount of carbon dioxide they pump into the atmosphere by more than a quarter.
Campaign group Seas at Risk has produced a report outlining the benefits of restricting how fast container ships should be allowed to travel.
There are currently no speed limits in international waters and they can only be imposed in some situations such as on harbour approaches and in coastal waters.
Most modern container ships cruise at around 20-24 knots (23-28mph) so a 20 per cent speed cut could reduce that to about 16-19 knots (18-22mph).
As well as slashing pollution, slowing boats down could also reduce underwater noise pollution by 66 per cent and whale collisions by 78 per cent, the group claims.
Global shipping is thought to generate just over three per cent of the world’s total greenhouse gas emissions so campaigners say any reduction would make an impact.
‘It’s a massive win, win, win, win,’ John Maggs from Seas at Risk told BBC News.
‘We’ve got a win from a climate point of view, we’ve got a win from a human health point of view, we’ve got a win for marine nature, we’ve got a potential safety gain, and up to a certain point we are saving the shipping industry money.’
CO2 emissions from ships are produced by the burning of fossil fuels in main engines, auxiliary engines and boilers.
Speed reductions can lead to significantly lower fuel consumption and in turn a reduction in CO2 emissions, the study claims.
Pollutants which campaigners say are bad for human health include black carbon, sulphur and nitrogen oxides.
Black carbon is a sooty black material that is emitted from gas and diesel engines, including ships.
It can increase the speed of heating in the Arctic region because it falls on the ice and limits its ability to reflect back sunlight.
The campaigners said whale-ship collisions happen ‘regularly’ but the risks of killing whales this way could be reduced if ships were slower.
In their report they wrote: ‘A three- to four-fold increase in the number of reported large whale–vessel strikes worldwide from the early 1970’s to the early 2000’s has been reported and attributed to increasing numbers, size and speed of ships.’
They said the risk of an animal dying during the collision could be reduced by between 10 and 22 per cent if ship speeds were 20 per cent lower.
While shipping companies support the need to cut their CO2 emissions, they are split on the need to reduce the speeds ships operate.
Danish shipping giant Maersk opposes any speed limits, saying they believe the focus should be on changing the way power is applied.
‘Focusing on power instead of speed limits will help deliver on the CO2 reduction targets set by the IMO, whilst rewarding the most efficient ships’, regulatory affairs director Simon Christopher Bergulf told BBC News.
Some companies are already reducing their speeds. The study found that in 2008 cargo ships slowed by an average of 12 per cent to cut fuel costs.
According to The Geography of Transport Systems report, most modern ships are designed to cruise most efficiently at between 20 and 24 knots.
Slower than this – known as slow steaming (18-20 knots; 21-23mph) – burns less fuel but make journeys take longer. This is predicted to become commonplace in future.
Ships can range down to about 12 knots (14mph) to save fuel before they start to plateau and wouldn’t get any benefit from going slower, that report said.
‘We think the best way to do this most effectively is with a direct speed limit, whether we get that or not is unknown, but ships will have to slow down in the future’, Mr Bergulf added.
Negotiators from the United Nations are meeting in London this week to discuss plans to reduce shipping speeds.
Carbon dioxide (CO2) is one of the biggest contributors to global warming. After the gas is released into the atmosphere it stays there, making it difficult for heat to escape – and warming up the planet in the process.
It is primarily released from burning fossil fuels such as coal, oil and gas, as well as cement production.
The average monthly concentration of CO2 in the Earth’s atmosphere, as of April 2019, is 413 parts per million (ppm). Before the Industrial Revolution, the concentration was just 280 ppm.
CO2 concentration has fluctuated over the last 800,000 years between 180 to 280ppm, but has been vastly accelerated by pollution caused by humans.
The gas nitrogen dioxide (NO2) comes from burning fossil fuels, car exhaust emissions and the use of nitrogen-based fertilisers used in agriculture.
Although there is far less NO2 in the atmosphere than CO2, it is between 200 and 300 times more effective at trapping heat.
Sulfur dioxide (SO2) also primarily comes from fossil fuel burning, but can also be released from car exhausts.
SO2 can react with water, oxygen and other chemicals in the atmosphere to cause acid rain.
Carbon monoxide (CO) is an indirect greenhouse gas as it reacts with hydroxyl radicals, removing them. Hydroxyl radicals reduce the lifetime of carbon dioxide and other greenhouse gases.
What is particulate matter?
Particulate matter refers to tiny parts of solids or liquid materials in the air.
Some are visible, such as dust, whereas others cannot be seen by the naked eye.
Materials such as metals, microplastics, soil and chemicals can be in particulate matter.
Particulate matter (or PM) is described in micrometres. The two main ones mentioned in reports and studies are PM10 (less than 10 micrometres) and PM2.5 (less than 2.5 micrometres).
Scientists measure the rate of particulates in the air by cubic metre.
Particulate matter is sent into the air by a number of processes including burning fossil fuels, driving cars and steel making.
Why are particulates dangerous?
Particulates are dangerous because those less than 10 micrometres in diameter can get deep into your lungs, or even pass into your bloodstream. Particulates are found in higher concentrations in urban areas, particularly along main roads.
What sort of health problems can pollution cause?
According to the World Health Organization, a third of deaths from stroke, lung cancer and heart disease can be linked to air pollution.
Some of the effects of air pollution on the body are not understood, but pollution may increase inflammation which narrows the arteries leading to heart attacks or strokes.
As well as this, almost one in 10 lung cancer cases in the UK are caused by air pollution.
Particulates find their way into the lungs and get lodged there, causing inflammation and damage. As well as this, some chemicals in particulates that make their way into the body can cause cancer.
Deaths from pollution
Around seven million people die prematurely because of air pollution every year. Pollution can cause a number of issues including asthma attacks, strokes, various cancers and cardiovascular problems.
Air pollution can cause problems for asthma sufferers for a number of reasons. Pollutants in traffic fumes can irritate the airways, and particulates can get into your lungs and throat and make these areas inflamed.
Problems in pregnancy
Women exposed to air pollution before getting pregnant are nearly 20 per cent more likely to have babies with birth defects, research suggested in January 2018.
Living within 3.1 miles (5km) of a highly-polluted area one month before conceiving makes women more likely to give birth to babies with defects such as cleft palates or lips, a study by University of Cincinnati found.
For every 0.01mg/m3 increase in fine air particles, birth defects rise by 19 per cent, the research adds.
Previous research suggests this causes birth defects as a result of women suffering inflammation and ‘internal stress’.
What is being done to tackle air pollution?
Paris agreement on climate change
The Paris Agreement, which was first signed in 2015, is an international agreement to control and limit climate change.
It hopes to hold the increase in the global average temperature to below 2°C (3.6ºF) ‘and to pursue efforts to limit the temperature increase to 1.5°C (2.7°F)’.
Carbon neutral by 2050
The UK government has announced plans to make the country carbon neutral by 2050.
They plan to do this by planting more trees and by installing ‘carbon capture’ technology at the source of the pollution.
Some critics are worried that this first option will be used by the government to export its carbon offsetting to other countries.
International carbon credits let nations continue emitting carbon while paying for trees to be planted elsewhere, balancing out their emissions.
No new petrol or diesel vehicles by 2040
In 2017, the UK government announced the sale of new petrol and diesel cars would be banned by 2040.
From around 2020, town halls will be allowed to levy extra charges on diesel drivers using the UK’s 81 most polluted routes if air quality fails to improve.
However, MPs on the climate change committee have urged the government to bring the ban forward to 2030, as by then they will have an equivalent range and price.
Norway’s electric car subsidies
The speedy electrification of Norway’s automotive fleet is attributed mainly to generous state subsidies. Electric cars are almost entirely exempt from the heavy taxes imposed on petrol and diesel cars, which makes them competitively priced.
A VW Golf with a standard combustion engine costs nearly 334,000 kroner (34,500 euros, $38,600), while its electric cousin the e-Golf costs 326,000 kroner thanks to a lower tax quotient.
Criticisms of inaction on climate change
The Committee on Climate Change (CCC) has said there is a ‘shocking’ lack of Government preparation for the risks to the country from climate change.
The committee assessed 33 areas where the risks of climate change had to be addressed – from flood resilience of properties to impacts on farmland and supply chains – and found no real progress in any of them.
The UK is not prepared for 2°C of warming, the level at which countries have pledged to curb temperature rises, let alone a 4°C rise, which is possible if greenhouse gases are not cut globally, the committee said.
It added that cities need more green spaces to stop the urban ‘heat island’ effect, and to prevent floods by soaking up heavy rainfall.