The sun was shining; the bands were good - well, some of them - and the summer had arrived at last. Tennis players fought it out at Wimbledon and cyclists raced down the Mall in the Tour de France. But as the crowd inside Wembley Stadium for the London Live Earth concert was joined by two billion viewers around the world, other things were happening yesterday too.
Live Earth took place on seven continents, over 24 hours. During that time five million people travelled by plane - and nearly 5,000 people died as a result of air pollution. More than 83 million barrels of oil were consumed - and the Antarctic lost a kilometre from its melting ice shelf. The population of the world increased by 211,000 - and the forests of the world decreased by 20,000 hectares.
All this happens every day - symptoms of the global crisis that Live Earth hopes to help to stop. And the true picture is even worse than we fear, The Independent on Sunday can reveal.
Startling new research shows that humanity is pushing the Earth to breaking point by devouring the life-support systems that make it habitable. Even before the feared climate change really begins the bite, the planet is already under intolerable strain. An unprecedented study by top ecologists and climatologists, to be published by the US National Academy of Sciences, shows that a quarter of all plant life in the world is being destroyed each year by the demands of just one species: homo sapiens.
"That is mind-boggling," said Kevin Wall, co-founder and producer of the Live Earth shows which started in Sydney, Australia, at 2am British time and ended in Rio de Janeiro early this morning. "It is part of the challenge we face, which is so overwhelming that people tend to go along with their lives in the same way, because it's invisible moment by moment."
Live Earth hoped to beat that inertia by challenging members of its unprecedented global audience to reduce their own carbon emissions and campaign for serious political action. "The Earth is a blue ball covered with a very thin layer of lacquer, within which the air, water and living beings exist," said the former US presidential candidate Al Gore, who also put the concerts together. "This fragile layer is all we have. It is our only home - and we owe it to our children and our children's children to protect it."
But the new research in 161 countries - the most extensive study ever made into humanity's impact on the planet's production of life, powered by the Sun - shows that the Earth is already in serious trouble. In some parts of the world humans are using up far more than 25 per cent of plant life for food, fuel and other needs. In Western Europe we gobble up 40 per cent of the earth's natural bounty, in Eastern Europe 52 per cent, and in India a staggering 63 per cent. About half of this is accounted for by growing crops and another 40 per cent in forestry and grazing domesticated animals.
"This is a remarkable impact on the biosphere caused by just one species," said the German government's chief adviser on climate change. The US Academy's study, actually carried out at Austria's Klagenfurt University and Germany's Potsdam Institute for Climate Research, is backed by some of the world's most distinguished experts. Dr Nathan Moore of Michigan State University called the results "alarming". Professor Christopher Field, founding director of the Carnegie Institution's Department of Global Ecology, said: "With millions of species sharing the leftovers, it is hard to know how many will be squeezed out of the game."
Global warming will place even greater strain on the natural world, the survey says. But it also warns that one of the main measures proposed to combat climate change - growing extra crops for to make biofuels - places "massive additional pressures on ecosystems".
Live Earth took place on seven continents in Sydney, Tokyo, Shanghai, Johannesburg, Hamburg, London, New York and Rio de Janeiro. Crowded House were headlining in Australia long before the doors opened at the new Wembley Stadium, and their lead singer Neil Finn said this event would shame other rock promoters and set a new standard for responsible shows. "This is the least we can do at this point in the planet's history. It's a groundswell we want to be part of."
But Roger Daltrey of The Who (not on the bill anywhere) had said: "The last thing the planet needs is a rock concert." And Arctic Monkeys said the artists appearing were patronising and hypocritical, "especially when we're using enough power for 10 houses, just for stage lighting".
British fans at Wembley were well aware of the absurdity of super-rich rock stars lecturing ordinary people about how to live a greener life. Darren Goddard, 32, a bricklayer from Norwich, was looking forward to seeing Madonna. But asked whether she would have come by National Express to cut down emissions, as he had, he just laughed.
"It is ridiculous and a bit insulting to hear them when they've got all that wealth," agreed his friend Jim Clancy, 45, a builder, " but you need big stars to attract people." And Maria Clancy, 32, a teaching assistant, said: "If she manages to make 100 people change their minds today then it's almost worth it."
Prime Minster Gordon Brown echoed the need for more awareness. "People are asking, 'What can I do?'" he said. "When I go round the country and I meet people, they say to me, 'Look, if we knew what we could do to make a difference to helping the planet, then we would do it.' One of the things we've got to do in the next few months is have more information about the different things that we can do to improve the planet."
Live Earth was organised by the Alliance for Global Protection, the charity set up by Al Gore when his unexpected hit film An Inconvenient Truth turned a failed US politician into the world's leading green statesman. Kevin Wall, his partner in making the concerts happen, was also the man behind the Live8 in 2005. Like those shows, this one was not after money. "The southern hemisphere - in particular Africa - is already the most affected by the climate crisis," Mr Wall told the IoS, "but Live Earth isn't about the haves and the have-nots. The air we breathe here is the same air they breathe in Africa and China. The crisis will affect us just the same, rich and the poor."
As a promoter he was aware how ridiculous and hypocritical it might look. "But it's not about what anybody has done in the past. This is about their commitment going forward. If we can get the rock industry and promoters to make a commitment, if we can get consumers to sign the pledge, we will achieve something."
Everyone watching was urged to sign up by text or online for a sevenfold pledge to plant trees, protect forests, buy from eco-friendly businesses, vote for green-minded politicians and make "a dramatic increase" in energy savings. But the pledge also involved promising to fight for new laws and policies, to demand that their country sign a new treaty - and the very specific demand that any new coal power station be able to trap and store the CO 2 it produces.
Inside the stadium, the power was coming from renewable sources, the organisers claimed, and food, drink and souvenirs were being sold in recycled or biodegradable packaging. The burgers came in boxes made from sugar cane and reed fibre and Madonna's backstage pass hung from a lanyard made from the recycled stems of grain crops. Her flights - and all those taken by Live Earth staff and performers - were offset. But most of that was only for this event.
Sharon Looremeta had come from her Masai village in Kenya to speak to the world from the Wembley stage. "We lived for many years with lots of animals and food but with time we have become poorer than any other human beings on earth," she said. "Our rivers have dried up. Our vegetation is drying up too because we do not get the rains we used to. Women cannot work and children are stopped from going to school because they must walk long distances to look for water."
How did it feel then, to share a microphone with some of the world's richest stars? "There is a disparity," she said. "But I have come to share our story and they want to hear it. They are human. They have feelings and morals. I can go back and say that people here have a commitment to help us and to change"
Even the reformed spoof rock gods Spinal Tap had their say on global warming. "We're premiering our new song called 'Warmer than Hell'," said the bass player Derek Smalls.
And in a speech in South Africa, the Benin singer Angélique Kidjo said: "Get your butt out there and do something. If we don't do something today, then when there's another tsunami then that cynical person, his arse is going to be on that wave."