Commentary in 2012

The latest carbon dioxide emissions continue to track the high end of emission scenarios, making it even less likely global warming will stay below 2 °C. A shift to a 2 °C pathway requires immediate significant and sustained global mitigation, with a probable reliance on net negative emissions in the longer term.

Decision-makers need to be able to respond to the question 'how much adaptation is enough?' even though there is seldom a simple answer.

Current United Nations structures are highly inequitable and obstruct progress towards international climate policy co-operation.

Doha marks the first stop on a roadmap to a post-2020 climate regime. The European Union could pave the way by building bridges with partners in key areas such as mitigation ambition, adaptation finance and deforestation.

There is a growing and urgent need to improve society's resilience to climate-related hazards and better manage the risks and opportunities arising from climate variability and climate change.

China is to introduce a national emissions trading system based on regional pilot projects despite structural hurdles ahead.

Carbon offsetting is a fraught science, but there are schemes that have additional benefits beyond their carbon-mitigation value.

How climate change science is conducted, communicated and translated into policy must be radically transformed if 'dangerous' climate change is to be averted.

The potential for power generation from geothermal energy in China is vast but as yet largely untapped.

Carbon emissions from cities represent the single largest human contribution to climate change. Here we present a vision, strategy and roadmap for an international framework to assess directly the carbon emission trends of the world's megacities.

The promise of a scientifically sound policy approach to tackle greenhouse-gas emissions in Australia gives hope that the country's efforts to mitigate climate change can make an effective contribution to international objectives.

Australia's carbon pricing mechanism leads the way with innovative design in price management and revenue recycling but could fall victim to partisan politics.

Twenty-one coherent major initiatives could together stimulate sufficient reductions by 2020 to bridge the global greenhouse-gas emissions gap.

Shale gas can be a powerful tool in combating climate change. However, its exploitation may also lead to undesired environmental effects that can conversely worsen climate change.

Emissions from tropical hydropower are often underestimated and can exceed those of fossil fuel for decades.

As host to the Rio+20 United Nations Conference on Sustainable Development, Brazil will draw international attention to its policy on climate change, but the measures announced so far are not commensurate with the recently set reduction goal.

The newly observed economic phenomenon carbon-market intelligence was worth over £35 billion in 2010–2011 and is forecast to experience annual double-digit growth over the next five years.

Predictions of a 40–140% increase in wheat yield by 2050, reported in the UK Climate Change Risk Assessment, are based on a simplistic approach that ignores key factors affecting yields and hence are seriously misleading.

Despite the decision by supermarket-giant Tesco to delay its plan to add carbon-footprint information onto all of its 70,000 products, carbon labelling, if carefully designed, could yet change consumer behaviour. However, it requires a new type of thinking about consumers and much additional work.

The claimed economic benefits of exploiting the vast Alberta oil-sand deposits need to be weighed against the need to limit global warming caused by carbon dioxide emissions.