The theme of World Environment Day this year is, ‘Many Species, One Planet, One Future’. What does this mean for a girl or boy on this planet, wherever their home happens to be? It is surely the opportunity to think about the rich diversity of everything that lives together on Earth, to recognise that this rich environment is the foundation on which human life is built, and to remember that individuals acting alone can influence the lives of us all in the years ahead.

Scientists have concluded that this planet experienced five ‘mass extinctions’ in the past, when a large number of species disappeared in relatively short and traumatic periods. We may even now be living through a sixth extinction: it is estimated that almost one third of today’s species could have disappeared by the end of the century.

The causes lie in the destruction of natural habitats, pollution and disease, and in climate change which acts as a catalyst. The major difference between this and past mass extinctions therefore is the extent to which humans are contributing to the scale of damage and the speed at which it is occurring. 

We have failed to put a proper value on the basis of human survival for too long. We need to reassess, understand better, and fully appreciate our complete and critical dependence on our environment. For instance, coral reefs provide food, storm protection, jobs, recreation and other income for more than 500 million people worldwide. 

Yet almost three quarters of the world’s coral reefs are threatened or have been destroyed. Biodiversity is essential to our being certain about the lasting availability of food and nutrition. But as we lose habitats and ecosystems, we undermine this richness and variety and reliability of supplies that affects our own survival. 

The momentum towards environmental catastrophe builds at a cascading pace. However, there is still a chance to achieve a different outcome. It requires us to work collectively to bring together political influence and decisions, skills, finance, and technology to develop a shared and fair pathway for all that can endure in future.

There is little time remaining to choose the direction we must travel together. 

The Commonwealth belongs to one third of all humankind on this planet, and is a vast network and opportunity for working and striving together. We have long championed the need for sustainable development – an approach to living that encourages development and growth opportunities whilst also protecting and managing limited natural resources.

In 1989, the Commonwealth’s Heads of Government pioneeringly stated this clearly in the Langkawi Declaration on the Environment. 

We have since put the ideas and goals of that Declaration into practice through, for example, the Commonwealth’s involvement with the Iwokrama Rainforest in Guyana, home to some 1,300 animal and 1,500 plant species.

At the core of Iwokrama’s success has been the creation of partnerships between the local population, international institutions and private enterprise. These partnerships have helped to create lasting development for the local communities, whilst protecting the ecosystem in which they live, that also provides benefits to the global community.

It is just one example of what can be achieved through cooperation, common purpose and shared goals about our environment and its future. 

Nearly 20 years have passed since the Rio Earth Summit that put the need to strike a balance between then environment and our human development needs at the top of the agenda of global debate.

Fresh momentum is now required to address the way in which sustainable development goals are agreed, pursued, and governed at the global level if we are to avoid environmental catastrophe. In the build-up to the forthcoming ‘Rio+20’ gathering in 2012, the Commonwealth will be tireless in promoting an outcome from that meeting that delivers development and that protects the world’s rich and diverse ecosystems.

The Commonwealth will also keep pursuing practical action: our Lake Victoria Climate Change Action Plan is a road-map already agreed by our members to help countries to build resilience and cope with the environmental challenges they face, including assistance to create green economies.  Our environmental good offices will build on this.

The world’s current development path points to a bleak future, but we have to act urgently in the belief that it is not too late. We have the knowledge, skills and abilities required to adjust to a better future that protects the environment, our fragile planet, and ourselves as well as those who come after us.

On this year’s World Environment Day, we should all reflect on how our individual and collective  actions can make a contribution that has a positive global impact in future.           

The author is the Commonwealth Secretary-General.