World will heat more sharply from 2010, warn scientists

By: TV Padma

(SciDev.Net) Another steep temperature rise is on the horizon, following the warmest decade since records began, scientists have warned. The UK-based Met Office Hadley Centre released its latest report on global warming trends at the UN Climate Change Conference in Copenhagen last week (11 December).

At least half of all post-2009 years could be hotter than 1998 "” the warmest year to date "” said Vicky Pope, head of the centre's climate change advice division. The year 2009 is expected to be the fifth warmest in the last 160 years. The Earth has warmed by about 0.15 degrees Celsius every ten years since the mid-1970s and all years from 2001 have been in the top 11 warmest on record, the figures show.

This is despite a relative slowdown in the rate of global warming this decade because of natural variations in ocean currents and the sun's activity "” a phenomenon now likely to end, resulting in the sharp climb in temperatures from 2010 onwards, according to the Hadley Centre.  A consortium of UK climate research institutes, led by the centre, is analysing the impacts of global warming with and without mitigation measures.

The report reiterates a prediction made in September that if emissions continue to rise under a "business as usual" scenario, temperatures could rise beyond two degrees Celsius more than pre-industrial levels between 2035 and 2055, reaching four degrees Celsius higher as early as 2060. This would have major implications such as reduced yields for all major cereal crops, as well as forest fires, drought, glacier melting and flood risks, said Pope.

There is at least a 50 per cent chance of restricting global warming to two degrees Celsius or less during this century, by peaking emissions in 2016 and then reducing them by five per cent per year by 2100, the figures show. And reducing emissions early could save at least 60 per cent of land that would otherwise have become unsuitable for crop growth by 2080 "” as well as reducing the number of people affected by water shortages and those at risk of flood from rising sea levels.

(Source: SciDev.Net, www.scidev.net)