Energy matters - it's in the bag!
A visit to any beach can reveal the growing problem of plastic. Mexico is certainly no exception. Its odds-on you will find some form of plastic litter.
All oceans are now impacted by the presence of plastic. Yet marine ecosystems offer enormous benefits to humans including food for billions of people, carbon storage, waste detoxification, recreational sports, endless holidays and the undeniable positive effect of being 'at the seaside'. So why are we trying so hard to destroy our marine ecosystems by deluging them with plastic rubbish?
Most plastic originates from hydrocarbons - by refining and altering - crude oil and natural gas, and in years gone by, also from coal and wood too. All plastics are toxic. PVC, or polyvinyl chloride, is widely recognised as the most toxic plastic. Its production and destruction releases a host of toxic chemicals - dioxins, organic chlorides, lead and cadmium - and greenhouse gases too.
An estimated 10 million tons of plastic enter the world's oceans from the land every year. And of course this 'marine plastic' is increasing. Plastics entering the oceans are predicted to increase by an order of magnitude within the next decade.
Over time, marine plastic fragments are broken into zillions of tiny pieces often only a few microns across, unseen without a microscope. It becomes permanently embedded in the environment, impossible to retrieve, slowly releasing its toxins and entering the food chain. It is irreversible environmental damage, unlike carbon dioxide in the atmosphere. Marine plastic is not something that can be overcome by technology. Once there, the vast majority will persist over geological timescales.
Retrieving some marine plastic is possible - typically the larger more visible items - plastic bags, bottles, sacks, shoes, chairs, cutlery & food packaging, buckets, abandoned fishing nets, ropes, surfboards and so on. Collecting these items is time intensive, expensive, and inefficient, but keeping the beaches clean does help. So much better to not let plastic enter the oceans in the first place.
The economic cost depends partly on where plastic enters an ocean, then where the oceans move it to, and how quickly the environment breaks it into tiny pieces. Longshore drift is well known to quickly move fragments of plastic along shorelines for hundreds and even thousands of kilometres. Some plastics have travelled more than 3000kms from their entry points, and recently a plastic bag was found on the floor of the deepest ocean, over 10,000m deep.
So it is not enough for Mexico to have a rigorous system for collecting and disposing of plastic. Mexico has to influence neighbouring countries to take action as well.
Marine plastic now impacts humans all across our globe. For example, it reduces the size of fisheries and reduces the livelihoods of those who work at sea or at the seaside. Tourists can expect a range of injuries - cutting themselves on sharp plastic debris, exposure to unhygienic items, getting entangled in bags and fishing lines etc.
A rapid buildup of plastic has the potential to dramatically shift the ecology of Mexico's oceans. Plastics introduce stress into the environment for fish and mammals, create a base for colonisation by bacteria & algae, and can lead to changes in water temperatures & acidity. Whereas natural flotsam such as seaweed and wood degrades and sinks within a few months, plastic can withstand prolonged exposure to waves and remain buoyant for decades.
What is clear is that marine plastic is globally a trillion dollar economic cost. The average cost per ton has little relevance; after all, marine plastic does not mix evenly throughout. And the damage caused is also impacted by how much plastic is already in the environment.
For Mexico, the economic cost of marine plastic is without doubt billions of dollars per year and will get bigger every year. Next time you buy some hydrocarbons in the form of plastic, or leave some plastic rubbish on one of Mexico's beaches, do think twice about the consequences.