Tiempo Climate Newswatch

The World Meteorological Organization has reported that 2004 was the fourth warmest year on record. The warmth was particularly marked over central Asia, China, Alaska, parts of the western United States and the North Atlantic Ocean. The year saw the warmest October on record over the world's landmasses. The ten warmest years world-wide have occurred since 1990. The rate of global warming since 1976, the start of the latest warming phase, has been three times that over the past 100 years as a whole.

2004 was also notable for hurricanes and typhoons. The first recorded hurricane in the South Atlantic Ocean occurred in March 2004. A record number of storms, eight, formed in the North Atlantic during August 2004. The seasonal total for the region was 15. The long-term average is ten. Tropical Storm Jeanne killed over 2,000 people in Haiti. Nine major storms struck the United States, resulting in damage estimated at over US$43 billion. Japan experienced a record number of ten tropical storm strikes, resulting in 209 fatalities. Towards the end of the year, a series of storms in close succession devastated parts of the Philippines leaving over 1,600 people dead or missing. Over the eastern Pacific as a whole, storm activity was below normal.

Much of Africa was affected by below normal rainfall amounts during 2004. Parts of southern Africa experienced dry conditions early in the year. Multi-season drought continued across parts of the Greater Horn of Africa. Kenya experienced an early end to the long rains. Food security was threatened by drought in Somalia and drinking-water shortages were made worse by poor rains in Eritrea. Parts of India experienced moderate drought conditions with the summer monsoon rains 13 per cent below normal. Drought also affected Pakistan, Afghanistan and southern China. Southern and eastern Australia has been affected by hydrological drought since the major drought of 2002/2003 and drought continued to affect parts of the western United States. Heat and dry conditions resulted in a record area being burnt by wildfires in Alaska.

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• ENN

• WMO press release

For the second year running, the Least Developed Countries (LDCs) failed to gain a commitment to full-cost funding for adaptation measures through the LDC Fund managed by the Global Environment Facility. The debate took place at the Tenth Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC), held in December 2004.

The problem is that most, if not all, adaptation measures have benefits beyond coping with the impact of climate change and the LDC Fund will not cover the proportion of the costs corresponding to these non-climate benefits. Indeed, even quantifying the proportion that could be considered related to the future impact of anthropogenic climate change poses a major scientific challenge. Moreover, with benefits in many areas, decision-making on funding becomes complex, requiring agreement across a number of sectors. The challenge for the climate negotiators is to create sufficient institutional flexibility to ensure that adaptation issues can be dealt with effectively under the UNFCCC.

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• Summary, ENB
• IIED

Speaking at a recent American Geophysical Union meeting in San Francisco, Mike Schlesinger of the University of Illinois at Urbana-Champaign warned that catastrophic climate change could result if global warming shuts down the thermohaline circulation in the North Atlantic Ocean. "If the thermohaline shutdown is irreversible, we would have to work much harder to get it to restart," he said. "Not only would we have the very difficult task of removing carbon dioxide from the atmosphere, we also would have the virtually impossible task of removing fresh water from the North Atlantic Ocean."

The thermohaline circulation transfers warm surface water from the southern hemisphere toward the North Pole. It is forced by variations in the density of seawater, related to temperature and salinity patterns. In the northern North Atlantic, the temperature of the water drops causing the water to sink and creating a return flow at depth to the south. "This movement carries a tremendous amount of heat northward, and plays a vital role in maintaining the current climate," according to Schlesinger. Increased precipitation and ice melt as global warming develops would add fresh water to the North Atlantic Ocean, making the surface waters less dense and halting the thermohaline circulation. The latest computer model results, reported at the San Francisco meeting, suggest that the shutdown of the thermohaline circulation may be reversible. Nevertheless, argues Schlesinger, "because the possibility of an irreversible shutdown cannot be excluded, suitable policy options should continue to be explored. Doing nothing to abate global warming would be foolhardy."

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Contrasting views

• Science Daily
• Innovations Report

• Union of Concerned Scientists
• CO₂ Science