For me, there was no scene in the Blue Planet II series more heart-rending than one in this week’s programme. In it, as snowflakes settle on the ground, a baby albatross lies dead, its stomach pierced by a plastic toothpick fed to it by its own mother, having mistaken it for healthy food. Nearby lies plastic litter that other hungry chicks have regurgitated.
Being fed lethal plastic debris is a risk that every young albatross now faces. This one scene symbolises a major problem that today threatens all sea creatures worldwide. Plastic is now found everywhere in the ocean, from its surface to its greatest depths.
There are fragments of nets so big they entangle the heads of fish, birds and turtles, and slowly strangle them. Other pieces of plastic are so small that they are mistaken for food and eaten, accumulating in fishes’ stomachs, leaving them undernourished.
And while in the sea, this debris may combine with other toxic chemicals that we have dumped in the ocean adding, some suspect, to the chemical contamination that we’re already seeing in a variety of sea creatures.
Every year, we dump around eight million tonnes of plastic into the sea. When ingenious chemists invented plastics over a century ago, the manufacturers proudly announced that this new material was, most wonderfully and valuably, indestructible. It would never wear out.
No one at the time, apparently, asked the question of what happened to this extraordinary new kind of marvellous material after we have finished with it. Now we know. It kills.
Plastic is not the only threat to marine life. So are rising temperatures. As the planet as a whole warms, so do the oceans. And the effect of that on marine life is, if anything, more damaging than it is to life on land.
If the sea temperature rises by one or two degrees in the tropics, the tiny coral polyps that over many centuries have built a reef begin to die. Within a few weeks, the whole reef is bleached to a ghostly white and the great variety of creatures that once lived there are homeless.
If the temperature remains high for too long, the reef may die, as we have witnessed twice on the Great Barrier Reef, in just the last two years.
In the Arctic, ice has been steadily disappearing – the extent of sea ice cover in summer has been reduced by 40 per cent in the last 30 years – so that the lives of many of its inhabitants, including seals, walruses and polar bears, are beginning to change radically.
Yet all is not yet lost. We can, right now, reduce the amount of plastic that we use in our everyday lives. Already many companies have realised the danger and have taken measures to reduce the amount of plastic bags and packaging they use. And we ourselves can simply stop using plastic unnecessarily.
We can also get together internationally to control the rate at which we take fish from the sea for our own consumption. Overfishing has in recent times destroyed fisheries that were once of almost unbelievable richness – of herring in the North Sea, and cod in Newfoundland.
Thirty years ago, a few conservationists recognised that hunting whales with ever-greater intensity and efficiency was bringing some populations to the very brink of extinction. So in 1986, the whaling nations of the world got together and agreed by a majority vote to stop doing so – except for a very few special purposes. Today, some whales have started to increase once again and now exist in heartening numbers.
We can also slow the rate at which the temperature of our planet is increasing by reducing the amount of fossil fuels we use to produce our energy, drawing instead on renewable resources such as tidal and wind power. A major step was taken when, in 2015, the industrial nations of the world agreed to work together to bring that about.
It is true that since then the United States has threatened to withdraw from that decision [with President Trump declaring, “I was elected to represent the citizens of Pittsburgh, not Paris.”] Let us hope that Trump will eventually recognise that the Paris Agreement was not about Pittsburgh, or even Paris, but the entire planet.
Our wellbeing is inextricably bound up with the health of the oceans. We depend on the creatures that live there for much of our food, and are likely to do so increasingly as our numbers continue to grow.
But, more than that, the oceans act as the planet’s air conditioner. They have absorbed 93 per cent of the heat trapped by greenhouse gases, produced in the burning of fossil fuels, since the Industrial Revolution, and they are continuing to do so, though this is neither desirable nor sustainable.
As I say at the end of Sunday’s final programme, never before have we been so aware of what we are doing to our planet – and never before have we had such power to do something about it. Surely we have a responsibility to care for the planet on which we live?
The future of humanity, and indeed of all life on Earth, now depends on us doing so.