by Staff Writers
Washington (AFP) Nov 12, 2013
World Bank President Jim Yong Kim said Tuesday that the deadly typhoon disaster in the Philippines should put an end to "silly" arguments denying climate change.
"If you think of the number of storms that have hit over the past year, the severity of those storms... The frequency of these events is increasing and that's exactly what the climate change scientists have predicted," Kim said.
"What I hope the tragedy in the Philippines helps us to do is to move away from having what I think are silly arguments about not really the science, but about science as a whole."
Some 10,000 or more are feared dead and hundreds of thousands left homeless after the super-typhoon Haiyan blasted through central Philippines on Friday.
It was the strongest tropical cyclone ever recorded to have made landfall, and has raised fresh questions over whether global warming is behind an increase in the intensity and frequency of such storms.
Speaking to journalists, Kim said people need to stop arguing over whether climate change is real, and do something about it.
"Ninety-five percent of climate scientists agree that anthropogenic (human-influenced) climate change is real, and that we have to do something about it or the impacts are going to be severe," he said.
He said the damages from such storms run about $6 billion a year and that the cost will mount sharply over the coming decades.
"Let's stop the argument and move forward," he said. "Let's make the investments we need."
He called for more spending on renewable energy and on more environment-friendly agriculture.
UN climate report: Key points
They include corrections to historic emissions of greenhouse gases. The IPCC on Monday said errors were found in the report's summary after the document was approved.
"Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen and the concentrations of greenhouse gases have increased... Human influence on the climate system is clear."
"Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions."
THE SITUATION TODAY
Mankind is likely to blame for observed warming since the mid-20th century.
"(...) Each of the last three decades has been successively warmer at the Earth's surface than any preceding decade since 1850. In the northern hemisphere, 1983-2012 was likely the warmest period of the last 1,400 years."
Warming since 1951 has been about 0.12 degrees Celsius per decade, slowing to 0.05 C per decade over the last 15 years. But the timescale is too short to properly evaluate.
Since about 1950, the number of cold days and nights has decreased, and number of warm days and nights has increased. Heatwaves are more common in large parts of Europe, Asia and Australia, says the report, adding that heavy rainfall has likely occurred more often and with greater intensity in North America and Europe.
The ocean stored more than 90 percent of the energy accumulated between 1971 and 2010, meaning scientists are virtually certain the upper ocean (0-700 metres deep) warmed from 1971 to 2010, and likely warmed between the 1870s and 1971.
Loss of Greenland's icesheet has likely increased from 34 billion tonnes per year in the decade to 2001 to 215 billion tonnes a year over the following decade. In Antarctica, the rate of loss likely increased from 30 billion tonnes a year to 147 billion tonnes a year over the same timescale.
Arctic sea ice contracted at a rate as high as 4.1 percent a decade from 1979 to 2012; there has been shrinkage of summer ice extent every season and in every successive decade. But Antarctic sea ice "very likely" increased by up to 1.8 percent per decade during the same period.
Snow cover has been retreating in the northern hemisphere since the mid-20th century. There has also been a "considerable reduction" in the thickness and extent of Siberian permafrost over the last three decades.
The global mean sea level rose by 19 centimetres from 1901-2010, an average 1.7 mm per year. This accelerated to 3.2 mm per year between 1993 and 2010.
Glacier loss and ocean thermal expansion account for about 75 percent of observed sea level rise since the early 1970s.
"The atmospheric concentrations of carbon dioxide (CO2), methane and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years." CO2 concentrations have increased by 40 percent since pre-industrial times, primarily from fossil-fuel emissions.
In 2011, levels of CO2, the main greenhouse gas, stood at 391 parts per million in the atmosphere.
For comparison, from 1750 to 2011, total man-made emissions of CO2 since industrialisation were 555 billion tonnes of carbon.
CO2 from fossil fuels and cements amounted to 375 billion tonnes of carbon. Deforestation and other land use accounted for 180 billion tonnes.
The ocean has absorbed 155 billion tonnes; natural terrestrial systems 160 billion; 240 billion are in the atmosphere.
THE FUTURE (to 2100)
In its projections for the future, the report uses four scenarios called Representative Concentration Pathways (RCP). These are based on the amount of heat-trapping carbon gas that enters the atmosphere. They comprise RCP2.6, the lowest; RCP4.5; RCP6.0; and RCP8.5, the highest.
"Global surface temperature change for the end of the 21st century is likely to exceed 1.5 C" compared to 1850, for all scenarios except RCP2.6.
The report sees these average rises in global surface temperature for the mid-term and the long-term, as compared to the start of the century.
(Note: The timelines are based on the average temperature measured over two decades, in order to gain a wider view. Their benchmark is also a two-decade span, the average temperature ranging from 1986-2005)
To gain the overall view of warming since the Industrial Revolution, about 0.7 C must be added (from 1850 to 2012, there has been warming of about 0.78 C).
2046-2065 2081-2100 RCP2.6 1.0 C (in a range of 0.4-1.6 C) 1.0 C (in a range of 0.3-1.7C) RCP4.5 1.4 C (0.9-2.0) 1.8 (1.1-2.6) RCP6.0 1.3 C (0.8-1.8) 2.2 (1.4-3.1) RCP8.5 2.0 C (1.4-2.6) 3.7 (2.6-4.8)Sea-level rise
Average rise in global sea level (in metres):
2046-2065 2081-2100 RCP2.6 0.24 (range of 0.17-0.32m) 0.40 (range of 0.26-0.55m) RCP4.5 0.26 (0.19-0.33) 0.47 (0.32-0.62) RCP6.0 0.25 (0.18-0.32) 0.48 (0.33-62) RCP8.5 0.30 (0.22-0.38) 0.63 (0.45-0.82m)Extreme weather events
Exceptional rainstorms are "very likely" to become more intense and more frequent over mid-latitude countries and the wet tropics. Monsoons will affect a greater area, last longer and intensify in many regions.
By 2100, year-round reductions in the extent of Arctic sea ice are seen under all scenarios. They range from a shrinkage in summer sea ice of 43 percent under RCP2.6 to 94 percent under RCP8.5, to eight percent of winter ice under RCP2.6 to 34 percent under RCP8.5
Hitting the 2C target?
To have a good chance of meeting the UN target of limiting man-made warming to less than 2C compared to pre-industrial times, all carbon emissions from man-made sources must be limited to about 1,000 billion tonnes, or gigatonnes.
"Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped. This represents a substantial multi-century commitment created by past, present and future emissions of CO2."
About 15 to 40 percent of emitted CO2 will remain in the atmosphere longer than 1.000 years while sea levels will rise for "many centuries" beyond 2100 due to thermal expansion. The rise will be between 1 and 3 metres by 2300 depending on if CO2 stabilises below 500 parts per million or goes beyond 700 parts.
The near-complete loss of the Greenland ice sheet over a millennium or more would drive up the seas by up to 7 metres. Rough estimates say the threshold for this is between 1C and 4C over pre-industrial levels.
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