Our guides from Save Brasil and the Brazilian Nature Agency had just finished explaining the importance of the Atlantic Forests of Brazil and were ushering us towards the forest when a dazzling emerald blur whizzed in front of us.  It danced over the crimson flowers, pausing to peer between the petals, searching for nectar.  It’s not often you get to show the Secretary of State (SoS) for the Environment, the Environment Minister for Scotland and the Commissioner for Sustainable Futures in Wales a hummingbird at 10 feet.  But there it was - glistening irradiances of green and violet, wings invisible as it hovered.

If a picture speaks a thousand words then seeing something with your own eyes must be worth many more, and that’s why we took some time out from the endless rounds of meetings here at the Rio+20 summit and brought these  members of the UK delegation to see the wonders of the Brazilian rainforest for themselves. And what a start for the visit!  Even the accompanying journalists were impressed.

You wouldn’t expect to find a rainforest in Rio, but Tijuca National Park, the location for our visit, sits within the city limits and covers two hills above Copacabana beach. If we’d stood in the same spot around 150 years ago then the view would have been very different. Instead of lush rainforest, we’d have been looking at the coffee and sugar cane plantations grown after the forest was cleared. But the forest was restored after the city’s water supply began to dry up and the slopes of the hills started to become unstable. It's a great example of safe guarding nature for the benefit of the services it provides for us - or in Rio jargon, ecosystem services.

So if people living over 150 years ago realised that destroying rainforests is bad for the planet and for us, then why are we still destroying them today, and what is the UK delegation doing to stop it?

Chatting as we walked through the forest, it was great to hear that Mrs Spelman (SoS) agrees with us about the importance of protecting rainforests. She was adamant that the UK (and the EU) was pushing hard to ensure that the final text helped save more of them. When asked to shed light on how it is that the UK government has allocated so much money to support rainforests and yet the BirdLife Forests of Hope programme, with projects ready to go, cannot get funding, Mrs Spelman invited us to contact the relevant officials to follow up.

But while we agreed on the importance of protecting our rainforests and the need for this to be included in the Rio text, we differed on the threat that agriculture poses to these amazing places.  As the global population increases, the amount of food we need is going to increase too. We need to ensure that this increase in agricultural activity doesn’t come at the expensive of the natural environment. Mrs Spelman was confident that the Rio text already had sufficient safeguards in place to prevent this, but when I read it I was left unconvinced. It still looked to me like it was encouraging a straight forward increase in production without taking nature into account.

The irony of the situation is this conversation took place in a field taken out of production for conservation reasons 150 years ago.