Much of the scientific and public focus on anthropogenic carbon dioxide emissions have been on climate impacts. Emission targets have been suggested based primarily on arguments for preventing climate from shifting significantly from its preindustrial state. However, recent studies underline a second major impact of carbon emissions: ocean acidification. Over the past 200 years, the oceans have take up `40% of the anthropogenic CO2 emissions. This uptake shows the rise in atmospheric CO2 considerably, thus alleviating climate change caused by anthropogenic greenhouse gas emissions.

Measuring the costs and benefits of projects intended to offset the emission of greenhouse gases is one of many thorny issues that the state of California must tackle as it begins drafting a cap-and-trade system of carbon credits.

The world's most pressing problems will be the focus of G8 talks next week, when leaders from rich nations and major emerging economies meet in Toyako on the Japanese island of Hokkaido. More than 30 years on, oil prices are again high on the agenda for the G8 gathering, which has climate change as its main focus. It is also expected to cover global food shortages, nuclear non-proliferation, African development and peace building.

Today's world trade volume is 27 times that of 1950. Trade liberalisation has made no small contribution to global warming due to spectacular growth in the transportation industry. Today, when they need to negotiate the climate regime to replace the Kyoto Protocol after 2012, industrial and developing countries bicker over what would constitute more climate-friendly trade rules.