Is The Focus On Plastics & Marine Debris Covering The Real Issue?

I’ve been thinking of writing this piece for a while. I’ll be honest with you… I am troubled. I’m a scuba diver and I love diving in great places. I’ve travelled the world and the seven seas to dive some of the greatest sites this planet has to offer. I’ve been lucky enough to see some amazing stuff and I’ve got more trips booked in. I’ve watched all the Attenborough documentaries and many more like it.

I work at a dive centre that is 100% Aware and makes a payment to PADI’s home charity Project Aware every time it certifies a diver. We organise regular beach, canal and ocean clean-ups. We recycle and campaign against debris and overfishing. We worry about sharks and the health of the oceans. We care for the planet.

By now I’m sure you see the issue. I’m struggling to reconcile my love of diving and travel with what I truly believe to be the biggest threat to life on earth and NOT just the oceans. Climate change – which whatever your views – the scientist say is real. I’m inclined to believe the staggering evidence which proofs that climate change is man-made and driven by the overproduction of greenhouse gases.

[caption id="attachment_22205" align="aligncenter" width="300"]Carbon Emissions Carbon Emissions[/caption]

The science bit

Take a Boeing 737 aircraft, used typically for short-haul flights, as an example. Emissions of this aircraft are around 90 kg of CO2 per hour. CO2 emissions generated by aircraft are generally released into the high atmosphere and are thought to have a greater greenhouse effect than CO2 released at sea level. The emissions are therefore adjusted accordingly and multiplied by a factor of 2.00, to give the equivalent of 180 kg CO2 per hour.

Further allowance is needed for fossil fuel energy used in:

  • Extraction and transport of crude oil
  • Inefficiencies in refineries (around 7%)
  • Aircraft manufacture and maintenance, and staff training
  • Airport construction, maintenance, heating, lighting etc

The Carbon Independent Calculator takes all the above factors into consideration and rounds up CO2 emissions to a value of 250 kg CO2 per hour flying! Sounds like a lot more than the 90 kg per hour we started with. Alternatively, the UK Department for Transport journey planner assumes 0.158 kg of CO2 per km, which is equivalent to 134 kg CO2 per hour for a plane flying at 850 km per hour.

What is our impact?

Now I realise that some people will argue that because a plane is flying anyway, and their added weight is pretty much insignificant, it makes no difference to the CO2 released whether or not they are on the flight. And so they will continue flying and make no effort to cut back or take any other action. But what they may not realise is that the decision made by an airline to fly new routes and to continue them (and to increase or decrease their frequency) depends upon the revenue received by the airline. Therefore, it’s not actually the travelling on the aircraft that causes the CO2 emissions, but buying a ticket which encourages the airline to persist with the route and continue to release greenhouse gases.

Consequently, the more money someone pays the airline, the more likely it is to continue or even increase its flights on a particular route. So technically, those buying high-priced peak tickets are more responsible for the planes flying than those buying cheap off-peak seats - and this effect can be multiplied by at least a factor of 10, since seat prices can vary by this much. Carbon calculators could perhaps incorporate this, but the practical difficulties would be hard to overcome. However, people who are finding it hard to cut back on flying could take the intermediate action of avoiding the peak-time highly-priced seats where the airlines are getting their largest income and making their greatest profits.

[caption id="attachment_22204" align="aligncenter" width="500"]Carbon Emissions & Planes Carbon Emissions & Planes[/caption]

So it could be argued that although air travel accounts for only a small fraction of global emissions, one transatlantic flight can add as much to your carbon footprint as a typical year's worth of driving.

What does this mean for the Ocean?

As divers, most of us are concerned about the ocean and the life that inhabits it. The impacts of man-made CO2 emissions are multi-layered.

Ocean warming

Ocean warming has an impact on marine species and ecosystems. Marine fishes, seabirds and marine mammals all face very high risks from increasing temperatures, including high levels of mortality, loss of breeding grounds and mass movements as species search for more favourable environmental conditions. Coral reefs are also affected by increasing temperatures, which cause coral bleaching and increase their risk of mortality.

Warming ocean temperatures are also linked to the increase and spread of diseases in marine species.

Additionally, the rise in sea surface temperatures is causing the intensification of El Niño events, which disrupts the natural flows of ocean currents, which in turn disturbs the location of ocean upwellings that deliver nutrients into the ocean and support the whole ocean food chains. It also causes changes to the timings and positions of ocean current, which disrupts migration patterns and breeding regimes.


Between 25 and 50% of CO2 emissions produced by the burning of fossil fuels is being absorbed by the oceans, and it’s thought that this process has considerably slowed the rate of global warming. This might sound like good news, but unfortunately all that CO2 doesn’t just conveniently disappear when it goes into the water! The problem is that CO2 combines with water molecules to make a weak acid called ‘carbonic acid’.

Biologists are very worried about the effect this will have on marine life. The problem is that a vast number of marine organisms build their skeletons and shells from calcium carbonate. But calcium carbonate dissolves in acidic solutions! Many researchers have showed that when these organisms are exposed to high levels of CO2, they cannot build their shells/skeletons properly. Truth is, not a single genus benefits from acidification.

[caption id="attachment_22210" align="aligncenter" width="500"]Carbon Dioxide Carbon Dioxide[/caption]

So …what can we do?

Flying is a major contributor to global warming and atmospheric CO2. Increases in CO2 levels contribute to the acidification of oceans. Travelling to go on diving holidays is helping to destroy the very things we love. Fortunately, the BBC has a helpful video on some things we can do to both minimise and mitigate our impact if we decide to continue to fly, you can have a look here:

In summary, these are:

  1. Just don’t fly. Take a train, ferry, share a car. All have lower CO2 outputs per km of travel.
  2. Travel light. The heavier the plane, the more fuel it needs to use to take off , fly and land. Most of us are dab hands at packing light anyway – taking your dive kit leaves no allowance for luggage anyway, but think about all the spares we carry with us. Perhaps we could adopt the principle of ‘team spares’ – instead of everyone taking a spare torch maybe just one or two of us…. the chances of everyone in the group losing their torch is minimal.
  3. Fly direct. Take-off and landing use more fuel, so taking the direct flight route is always better.
  4. Resist the upgrade. Sit in the cheap seats. The World Bank state that your emissions are 3 times higher in business class or first class than economy.
  5. Chose your airline. Some airlines use more fuel than others. Generally, the more modern the fleet the lower the emissions.
  6. Fly from your local airport. This way at least you don’t add to the problem with your travel to and from the airport.
  7. If you do decide to travel, then we need to offset the carbon. Some people say that doesn’t work, but merely reduces the problem. However, if we can mitigate our own impact then at least we don’t add to the problem. There are lots of ways to offset your carbon. I used the website below to calculate the Carbon Offset cost of my last holiday to Egypt. I used/generated 1.6t of CO2. To offset costs £33 – I feel that’s a small amount to add to the cost of a £1500 dive holiday.

Oh…and if you do decide to travel and do offset your carbon, don’t forget that you can still do good in other ways.

    • Make every dive a debris dive wherever you go! Despite the existential nature of the climate change threat, marine debris is still a major threat to aquatic life.
    • Make sure your dive techniques are good. Employ good buoyancy control and the ‘look don’t touch’ philosophy.
    • Wear reef-friendly sunscreen and perhaps adopt other low CO2 and environmentally friendly products and materials and goods, like the Ocean Positive range from Fourth Element.


I don’t want to go give up diving and seeing all the amazing things this beautiful planet has to offer. Instead, I am going to minimise the impact my dive travel is having on the environment. I for one am now going to offset my personal carbon use with the help of this site:

I am also going to contact the major dive tourist companies to see what they are doing.

[caption id="attachment_22206" align="aligncenter" width="480"]Green Plane Green Plane[/caption]

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