Like all ambitious schemes, this one - which resuscitates an idea mooted in Egypt as long ago as 1913 - faces many challenges: the eurozone crisis, political fallout from the Arab Spring, and technical issues such as how to clean the solar field's reflecting mirrors.
But after the Durban climate conference last December, DII's project signals that the top-down approach to limiting carbon emissions through international deals is giving way to a ground-up attitude that stresses action.
There are other signs of the same trend: this year the European Union introduced a carbon tax on airlines that use its airports; Scotland is investing in wave power; California is embracing renewable energy, clean fuels, a cap-and-trade programme to limit emissions, and other green policies; Ecuador wants to preserve its forests by getting donors to pay it to keep oil in the ground; China, the world's biggest greenhouse gas emitter, last year approved its 12th Five Year Plan, which aims to tackle energy consumption and CO2 emissions. Further down the chain, growing urgency about reducing emissions can mean corporate investment in renewable energy, municipal emphasis on public transport, or a family insulating their home.
While a binding global deal remains vital, the United Nations' most important role may be to co-ordinate such initiatives.
Writing in the journal Nature in November, Elliott Diringer, executive vice-president of the Centre for Climate and Energy Solutions in the United States, suggested that although the 1994 Kyoto Protocol was "an important emblem of multilateralism", it had become "more of an impediment than a means to genuine progress.
"We need to appreciate that no one process will deliver a solution," Diringer said after Durban. "We bought into the fallacy that you could drive the effort from the top, via an international agreement. I don't think the record has proven that. Where the action needs to take place is on the ground."
Action would happen only once there was a political consensus to act domestically. "It's only then that [states] are in a position to take on a binding commitment."
Durban did produce one breakthrough: the US, India and China - the biggest greenhouse gas producers - reached a legally binding deal to reduce emissions. The accord broke an impasse between developed and developing nations that had bedevilled past talks. The treaty will take effect by 2020.
The deal tacitly acknowledges that the world is a different place than in 1992, when the US was the key player at the Rio Earth Summit. Since then the world economy has been remade by a rapidly growing, younger population, and climate change has become a more urgent challenge.
Durban delegates heard sobering news from climate scientists. Nine of the 10 warmest years have occurred since 2000. Since the 1950s, each decade has been warmer than the last. Efforts to limit temperature rise to 2C - when runaway climate change could begin - are further threatened by fears that a warming world will unlock millions of tonnes of methane from melting Arctic permafrost. Severe weather will exacerbate droughts, floods and heatwaves, with dire social, economic and political consequences. Time, said the scientists, was fast running out.
"It seems to me as a physicist that there is a very simple argument: if you have a warmer atmosphere, you have more convection - the great thermals rise higher - that turns into rain falling from a greater height, which is more damaging," says Lord Julian Hunt, who headed Britain's Meteorological Office, has campaigned for efforts to limit emissions, and is vice-president of Globe, the Global Legislators Organisation. "This is happening all over the world."
This race-against-time scenario presents the world with a stark choice: reduce emissions or suffer the consequences.
The old world order has vanished. Developed nations such as European Union members and the US are still mired in fallout from the global financial crisis, while the Brics - Brazil, Russia, India and China - are among a group of industrialising nations reshaping the economic order. The nations on the rise must balance rising demands for energy, water and other resources if they are to grow and sustain prosperity. Many see a green economy as the way forward.
The divide between developed and developing nations is shifting to a belief that we are all in it together.
"The shape of the debate is changing from one about sharing a global burden - with governments naturally trying to minimise their share - to one of realisation that acting on climate change is in the national interest," said Globe's president, Lord Deben, in comments on a 2011 study of climate change legislation in the world's 16 largest economies, done with the London School of Economics.
It stressed that any climate deal "will only reflect political conditions, not define them".
As emissions rise, grassroots concern about climate change has grown, and one of the results is a growing constituency that has a vested interest in change.
"It's something people need to be kicking in at home," says Diringer. "And until we can align politics domestically for stronger climate action, it's going to be difficult to align politics globally."
The high-carbon model made the West rich, and shifting to a sustainable economy is a huge ask, involving political courage as states confront mammoth challenges on infrastructure, energy, transport, construction and resources.
It is a change that is likely to produce big winners and losers.
Finding the necessary funding is a daunting prospect. It is unclear how developed countries now committed to austerity will find US$100 billion ($126 billion) for a Green Climate Fund to help developing nations fight climate change, as pledged at Durban. One option is in so-called "green growth".
"It has to happen in all different development contexts ... at local, state, regional levels," says Nathan Hultman, from the University of Maryland School of Public Policy, who believes clean technologies must be introduced urgently.
"How do we get that to happen? The answer is at local, state, regional levels. The most powerful players remain the national governments. Domestic energy policy is key to doing this technology deployment."
Governments and multinationals must stump up, maybe by expanding a "green bonds" programme being introduced by the World Bank and other multilateral lenders. The Economist reports that about US$5 billion in such bonds has been issued, with the proceeds invested in environmentally friendly projects. "We'll need massive amounts of capital in the next 20 to 25 years," says Hultman. "Some will go into fast-growing economies. Some to nations that have done much of their growth. The energy technology sector alone will need US$16 trillion to $20 trillion, involving hundreds of thousands of individual capital deployments. How will those decisions be made?"
But change is not impossible. Since the Earth Summit, environmental ideas have gone mainstream. Greens are now political players, and entrepreneurs such as DII sense opportunities.
California has long set an example in the shift to a low carbon economy. Last year the US adopted better vehicle fuel mileage standards pioneered by the Golden State. The US wants one million plug-in electric vehicles on the road by 2015, a scheme that requires collaboration between government, car companies and power utilities.
The National Resources Defence Council's Kristin Eberhard believes standards for energy efficiency and renewable energy (which must supply one-third of California's electricity by 2020) are likely to be adopted state by state.
The Western Climate Initiative, California's bid to create a regional cap-and-trade scheme involving other western states, Mexico and Canada, was stopped by the recession. But the EU's Emission Trading Scheme pushes the same concept.
The EU scheme was applied to aviation in January. Bloomberg New Energy Finance estimates that the cost to aviation - to be recouped from passengers - will amount to 0.24 per cent of revenue this year, rising to 0.54 per cent in 2020.
Aviation, like commercial shipping, was excluded from Kyoto. The EU's move has provoked retaliation from China, which said it would block orders for Airbus jets worth US$14.5 billion, and Airbus said it had received threats of retaliation from 25 other nations as well.
But pressure to make aviation pay for, and reduce, emissions is increasing. We are entering the carbon tax era.
"You'd be a brave person if you didn't think this was going to be a feature of the landscape," says Simon Terry, executive director of the Sustainability Council of New Zealand.
"The first and most interesting challenge on this front is the EU aviation tax. There really is not much doubt the World Trade Organisation will accept carbon border taxes. But there's an awful lot of resistance coming from the US, and also from China."
Still, Beijing recognises the contradictions inherent in responding to climate change while growing its own economy. Its carbon footprint is immense, and the country's CO2 emissions doubled between 2003 and 2010, to nine billion tonnes.
As the world's top energy user, it drives fossil fuel exploitation.
But it is also the world's top manufacturer of solar panels, has huge forestation projects and is building "green cities" as part of its professed aim to build a low carbon economy. This can range from grand projects to simple policies such as a plan to swap incandescent bulbs for more energy-efficient lighting in five years.
"The ultimate goal is for countries to adapt to changes in climate we expect to happen," says Hultman. "We also hope to accelerate the transition to a low-carbon energy future."
Germany, Mexico and South Korea are going down this path, and Australia has pushed through a carbon tax, to be introduced in July, though it remains highly controversial and the Opposition has promised to scrap the tax if it wins power.
Ultimately, the great generational issue of the 21st century is not slashing debt. Instead, it's about growing green economies and reducing emissions so our profligacy doesn't condemn coming generations to a bleak future.
