This report analyses pledge on emissions reductions put forward by Parties in the Cancún Agreements, including information emerging since the negotiations took place in 2010.

It focuses on the uncertainties and risks of achieving the goal of limiting the global temperature increase to 2 degrees Celsius, and provides a detailed overview what the pledges and actions of the 12 countries and regions with the largest emissions could mean for reduction targets.

The report highlights that since the Cancún negotiations, developing countries have published new information about their emission projections which have led to higher than expected emission levels, and have increased the emission gap.

It suggests that a selected set of mitigation options in addition to existing pledges could result in emission reduction which would narrow the gap towards achieving the two degrees Celsius goal. It also concludes that uncertainties in accounting rules and projections could mean that global emissions remain at business-as-usual projections for 2020.

This policy brief, published by the Global Canopy Programme, proposes a system called Proactive Investment in Natural Capital (PINC), to reward countries for conserving large areas of tropical forest that act as 'global utilities' providing ecosystem services essential for preserving global food and energy security.

The authors suggest that the system, could complement current proposals for reducing emissions from deforestation and forest degradation (REDD). They argue that REDD could encourage countries with historically low deforestation rates to destroy their forests. They point out that if REDD successfully brings deforestation rates down — to zero eventually — then in the long-term, countries will not be able to receive payments for reducing deforestation.

The alternative, PINC, would build on existing systems that pay for ecosystem services, such as eco-certification, although scaling-up funding for standing forests is still a challenge, say the authors. To be effective, PINC requires capacity building and improved governance across the world. Land tenure reform will be needed in many countries, as will local participation in decision making and training in forest management. But, if appropriately designed, PINC could provide local communities with co-benefits such as poverty alleviation and biodiversity conservation.

Several factors influence the costs of greenhouse gas mitigation. This report illustrates the importance of one such factor — international emissions trading — in reducing the costs of carbon control. The authors argue that an international greenhouse gas emissions trading regime will significantly lower global mitigation costs.

The Third Assessment Report of the IPCC's Working Group 1 builds on past assessments and incorporates new results from the past five years of climate change. It descibes the current state of udnerstanding of the cliamte system, and provides estiamtes of its projected future evolution and their uncertainties.

Many hundreds of scientists from around the world participated in the preparation and review of the report, which states that "there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities".