The tragedy of climate commons

The tragedy of climate commons

Imagine a group of 100 fisherman faced with declining stocks and worried about the sustainability of their resource and their livelihoods. One of them works out that the total sustainable catch is about 20% of what everyone is catching now (with some uncertainty of course) but that if current trends of increasing catches (about 2% a year) continue the resource would be depleted in short order. Faced with that prospect, the fishermen gather to decide what to do. The problem is made more complicated because some groups of fishermen are much more efficient than the others. The top 5 catchers, catch 20% of the fish, and the top 20 catch almost 75% of the fish. Meanwhile the least efficient 50 catch only 10% of the fish and barely subsist. Clearly, fairness demands that the top catchers lead the way in moving towards a more sustainable future.

The top 5 do start discussing how to manage the transition. They realise that the continued growth in catches - driven by improved technology and increasing effort - is not sustainable, and make a plan to reduce their catch by 80% over a number of years. But there is opposition - manufacturers of fishing boats, tackle and fish processing plants are worried that this would imply less sales for them in the short term. Strangely, they don't seem worried that a complete collapse of the fishery would mean no sales at all - preferring to think that the science can't possibly be correct and that everything will be fine. These manufacturers set up a number of organisations to advocate against any decreases in catch sizes - with catchy names like the Fisherfolk for Sound Science, and Friends of Fish. They then hire people who own an Excel spreadsheet program do "science" for them - and why not? They live after all in a free society. Full blog post