REPORTING FROM JOHANNESBURG, SOUTH AFRICA -- The last 15 years have been the hottest on record and included all 10 of the warmest years, the U.N.'s World Meteorological Organization announced Tuesday as 20,000 delegates from more than 190 countries met in South Africa to try to hash out a way forward to halt climate change.
This year so far has tied as the 10th-hottest year since records began in 1850, and is the warmest year while the La Nina phenomenon was present, a period when ocean temperatures are cooler, according to the organization's annual report on the global climate.
"Our science is solid and it proves unequivocally that the world is warming and that this warming is due to human activities," said Michel Jarraud, secretary-general of the WMO, in a statement.
Greenhouse gas emissions continued to rise and the world is fast approaching a global average temperature rise of 2 degrees to 2.4 degrees Celsius, Jarraud said.
World leaders have agreed in the past on the need for action to keep the rise in temperature beneath the 2 degrees Celsius (3.6 degrees Fahrenheit) that scientists say represents a safe level. But there is pessimism about whether the ongoing conference in the city of Durban -- a gathering known as COP 17, the 17th conference of parties to the United Nations Framework Convention on Climate Change -- can negotiate an extension to the 1997 Kyoto Protocol, the only treaty with binding reductions in greenhouse emissions, which expires next year.
If the temperature rises more than 2 degrees Celsius, the world would see irreversible changes leading to mass extinctions and other catastrophic events, according to scientists.
The La Nina phenomenon this year has been associated with extreme weather across the globe, according to the agency: Drought in East Africa led to tens of thousands of people dying of starvation. There were droughts in the southern United States and Pacific region, catastrophic flooding in Thailand and Asia, southern Africa and eastern Australia, and one of the most active tornado seasons on record.
Surface temperatures were higher than average in most parts of the world and were 4 degrees Celsius higher than average in northern Russia during much of the winter.
Sea ice in the Arctic ocean was at its second lowest level on record.
-- Robyn Dixon
Photo: In Wichita, Kan., participants take a water break at a gathering of elite drum and bugle corps during a July heat wave that spread across much of the United States, from Texas to North Dakota. Credit: Mike Hutmacher / Wichita Eagle