A mounting sense of concern about the threat to oceans

Both are the result of massive human consumption and output, often with little regard to its consequences.

Yesterday the actor Harrison Ford spoke about protecting the oceans, and criticised those who denigrate science.

While it is often tedious to hear wealthy celebrities get on their high horse about such matters, the damage that is being done to the oceans is something that is a source of genuine and mounting concern.

The hugely respected broadcaster Sir David Attenborough has said that oceans are under the greatest threat in history.

His stunning TV programmes have illustrated to the world both the wonder of the seas, their importance in the ecosystem, and the challenges they face.

It is hardly a surprise that there is so much environmental damage. Think of the plastic that any one individual can open and discard in a day, and it only takes a small number of thoughtless people to cause massive pollution.

A walk along any beach in Northern Ireland will show signs of plastic waste. In third world countries with poor waste management, beaches are filled with such rubbish.

And it is hardly surprising that we might be damaging the atmosphere either. Think of the fuel that is used to power cars and planes and the smog that was apparent 50 years ago, when traffic was a fraction of current levels, let alone now.

The science around climate change is disputed, but mainly the extent. No serious scientist says that human emissions do not play some role in the climate. The big debate is over extent, whether it will be catastrophic or manageable over time.

Science will help find a solution: less damaging plastics and lower emissions. But thoughtful human conduct too ought be something on which conservatives, socialists and neithers can agree.