If 2010’s Cancún climate talks brought the UN negotiations back from the brink, December’s Durban meeting put them back on track, goes the consensus. But how much closer does the Durban Platform bring us to a comprehensive climate treaty – and does it matter? Mark Nicholls reports

Just two days before the Cross-State Air Pollution Rule was due to come into effect, a federal court slammed on the brakes. Gloria Gonzalez reports on latest dose of regulatory uncertainty for US utilities and emissions markets

US environmental and renewable energy credit markets are anxiously awaiting a crucial CFTC ruling. Felicity Carus reports

US water infrastructure is crumbling, inefficient and unsustainable. But it also offers enormous opportunities for far-sighted investors, says Sharlene Leurig

The oil majors are betting big on gas, while throwing some loose change at alternative energy technologies. But they are also banking on energy efficiency extending the life of the internal combustion engine. Jeremy Lovell reports

The Western Climate Initiative is finally operational, but with only two of its planned 11 members. Gloria Gonzalez reports on what this means for its carbon market – and on the potential for it to gather both momentum and members once more

Tammy Newmark has proved it’s possible for investors to make money while saving the planet and alleviating poverty. She tells Christopher Cundy how

Frank Jotzo analyses Australia’s package of climate legislation – which puts this erstwhile carbon laggard at the forefront of efforts to tackle global warming

It is Australia’s move to price carbon, ultimately through a cap-and-trade scheme, that has generated most attention – and controversy. But carbon pricing is just one element of an ambitious reorientation of the tax and benefits system to penalise pollution and reward work, says Australia’s climate change minister, Greg Combet

California’s ambitious renewables and carbon targets are set to revolutionise its electricity system, with Cal ISO at its centre. Its CEO Stephen Berberich talks to Felicity Carus

Investors are piling into a US natural gas boom built on ‘fracking’. But with an uncertain regulatory climate, they would be well advised to keep an eye on potential environmental liabilities, says Tom Mounteer

The roll-out of Europe’s smart grid and smart metering will create enormous demand for capital – and a substantial investment opportunity, says Hans Meissner

After a dismal outcome in Copenhagen two years ago, the UN climate process was dismissed as irrelevant by many observers. But new life was breathed into the process in Durban – can what happens next live up to the promise? Katie Kouchakji reports

The weather market hasn’t escaped the effects of the drop in risk appetite in commodity markets more broadly – but end-user business remains solid and new opportunities, such as in renewable energy, are keeping participants busy. Mark Nicholls reports

It’s been a dire year for EU emissions trading and the Clean Development Mechanism – but things look brighter in California and Australia. Christopher Cundy reports

While the US has largely avoided the financing freeze afflicting the European renewables market in recent months, financiers are nervous about what 2012 might hold. Mark Nicholls reports

Not for the first time, traders and emitters in the US environmental markets are anxiously awaiting possible judicial intervention – this time, in the EPA’s newly minted CSAPR markets. Gloria Gonzalez reports

Mark Nicholls on what the 'breakthrough' at the UN climate talks really means

Dallas Kachan gives his predictions for the clean-tech sector in 2012, with plenty of eggshells overshadowed by one big possible bombshell

The latest collapse in the carbon price is once more raising profound questions about the future of the EU’s trailblazing emissions trading programme. Mark Nicholls reports