Nature certainly seems to be rebelling against humanity on many fronts. Even seaweed is coming back to haunt us for our crimes against the environment.

A stretch of beach in France was closed recently after a horse rider lost consciousness as a result of rotting seaweed. The horse unfortunately didn't make it. Other residents have also been treated in hospital.

It's not some new, deadly form of seaweed mutated as a result of exposure to nuclear waste (France has a huge nuclear power industry), but a normal variety that's been washing up in huge volumes.

As the seaweed rots, hydrogen sulphide (also known as rotten egg gas) accumulates under it and when the crust is broken, the poisonous gas is released. Hydrogen sulphide is highly toxic, as lethal as cyanide.

The cause - massive amounts of nitrates leaching into nearby rivers from agricultural activities that then enter the ocean and act as a fertilizer for the seaweed; of which 70,000 cubic meters is being removed from Brittany's beaches each year.

In a world that's gone to the lengths of turning natural gas into nitrogen based fertilizers and will soon use coal for the same purpose; it's not like we have nitrogen to burn (excuse the bad pun). We need to be minimizing nitrate runoff and reusing it.

Similar nutrient overdose isn't just occurring in France, but in many places around the world. For example, what's known as "dead zones" have doubled in size in the Gulf of Mexico in recent years.

Dead zones are another man-made phenomenon where an excess of nutrients cause algae blooms which can then take up all the available oxygen in the water; leaving it uninhabitable for other aquatic organisms.