More than 190 countries are gathered in Rio for the largest ever United Nations summit on the environment.
Rio+20 , called 20 years after the original Earth Summit, officially runs from 20th to 22nd June when ministers arrive for the ‘High Level Segment’.
However in an extraordinary move the Brazilian hosts have managed to get an 80-page agreement already agreed by environment ministers before the world leaders even arrive.
The text has yet to be signed off by heads of government, but Mrs Spelman said she did not expect anything to be dramatically changed.
“Whilst there is still a lot of work to do, this agreement means we have made progress towards achieving what the Rio Earth Summit set out to do – to get the world on the right path to achieve cleaner and greener growth that ends the damage we have done to the environment and helps end poverty,” she said.
The Future We Want commits the world to creating a new set of ‘sustainable development goals’.
The SDGs, as they will be known, will work like the existing Millennium Development Goals to drive action on sustainable food, water and energy for all.
The United Nations General Assembly will appoint a group of representatives from 30 countries by September to develop the goals. It is expected the goals will focus on food, water and energy set come into force in 2015.
Mrs Spelman said it could transform the way the world works, including forcing countries like Britain to use food, energy and water in a more sustainable way.
“The agreement on Sustainable Development Goals is a good outcome. We have backed SDGs from the outset and helped drive them from a good idea to a new agreement that will elevate sustainability to the top of the agenda. We had wanted to get agreement on themes of food, water and energy, which will now be our next aim.”
However environmentalists said the agreement was too weak.
For example plans to phase out fossil fuel subsidies only reaffirms previous commitments to phase them out if they "harmful and inefficient", without setting a date.
Jim Leape, WWF Director General, said important issues like halting deforestation, loss of species and overfishing have been watered down.
He said that the agreement should have agreed the themes of SDGs and a timetable in which they should be agreed.
At the moment he feared the agreement is too vague to force countries to act.
“It’s up to world leaders to get serious about sustainable development and save this process. If they approve what’s on the table now without significant changes, they’ve doomed Rio+20 to ridicule,” he said.
Kumi Naidoo, Greenpeace International Executive Director said the agreement has nothing to force countries to take action, meaning environmental degradation will continue.
“We were promised the 'future we want' but are now being present with a 'common vision' of a polluter’s charter that will cook the planet, empty the oceans and wreck the rain forests.“
“This is not a foundation on which to grow economies or pull people out of poverty, it’s the last will and testament of a destructive twentieth century development model,
“World leaders will begin to descend on Rio today and we have to ask why? We were promised a green economy, the Future we Want, but all we can look forward to is three more days of Greenwash.”
World leaders will now spend three days negotiating the text.
Mrs Spelman said it was unlikely it will change drastically but NGOs are hoping it will be significantly strengthened.
Article originally appeared in The Telegraph.