SciDev.Net: Four Arab Gulf states have pledged a total of US$750 million to a new fund for tackling climate change. The announcement was made on 18 November at the end of a two-day summit for leaders of the Organization of the Petroleum Exporting Countries (OPEC) held in Riyadh, Saudi Arabia. Saudi Arabia will invest US$300 million in the fund, with Kuwait, Qatar and the United Arab Emirates pledging US$150 million each. The fund aims to support cleaner and more efficient petroleum …