A new global plan for nature is under development in Sharm el-Sheik, Egypt this week where governments from around the world are meeting at the Convention on Biological Diversity.

This is the 14th such gathering since the Convention was born back in 1992 at the Rio Earth Summit and it’s fair to say that progress towards halting the loss of nature over the past quarter century has mostly failed.

Signatories to the Convention accept this and understand that the new plan, to run from 2020 to 2030, will need to be much more ambitious if we are to reverse the catastrophic loss of biodiversity.

One topic of conversation here on the Red Sea coast is the need for more compelling communication of the biodiversity crisis to an often disengaged public. There is talk of defining an ‘apex target’ which, in one number, would give an indication of the health of nature in a given country or region.

Delegates cite the ‘below two degrees’ climate change target as an example of a simple, powerful number widely understood and communicated by the media. Perhaps if we had an equivalent target for nature then the public would take more interest and put pressure on politicians to take more action on reversing degradation of the natural world.

The problem is that nature is more complex than carbon. There are many ways to measure and monitor biodiversity together with multiple solutions that will need to be deployed if we are to fix the extinction crisis.

The half-Earth idea is provocative and bold but in the end is unlikely to be embraced as a target because it could create as many problems as it solves.

One apex target, first suggested by the famous biologist E.O Wilson, is for half of the Earth to be set aside for nature. This passes the simplicity test but raises many difficult questions. What, for example, would the consequences be for nature outside the protected half and how could we possibly prevent leakage of environmental impact from what would be an increasingly densely populated human half of the planet?

The half-Earth idea is provocative and bold but in the end is unlikely to be embraced as a target because it could create as many problems as it solves.

Another apex target idea is to use the IUCN (International Union for Conservation of Nature) Red List to assess the extinction risk of species as a kind of barometer of life on Earth.

What the IUCN Red List does is classify a species by how likely it is to become extinct, from ‘least concern’ on one end of the spectrum to ‘critically endangered’ on the other. The bad news is that is of the 96,500 species on the IUCN Red List, more than 26,500 are threatened with extinction, including 40% of amphibians, 34% of conifers, 33% of reef building corals, 25% of mammals and 14% of birds.

These percentages could be the basis of the new, simple apex target we are searching for, but many more species would need to be assessed and we are short on time.

The global plan for nature is one plan we must get right.

The global plan for nature will be signed off at the 15th meeting of the Convention on Biological Diversity in China in 2020. I’m not exaggerating when I say it may just be the most important international plan of action humankind ever agrees.

The collapse of global ecosystems cannot happen. Nature regulates our climate and provides us with food, shelter and medicine. It gives us joy and inspires our cultures, our art and our spirit of adventure. The global plan for nature is one plan we must get right.

Jonny Hughes, Chief Executive

This article first appeared in The Scotsman on 27 November.