I Guess We Need More Data (or the World’s Biggest Control Chart)

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Every performance improvement professional has heard this: ” we don’t have enough data.” Sometimes that is correct (or more precisely, the sample size yields a level of statistical error that is not acceptable for the purpose of the decision and risk tolerance) but sometimes it’s a cop-out. You should decide for yourselves what you make of the report from the World Meteorological Organization titled “The Global Climate 2001-2010: a decade of climate extremes” (http://www.wmo.int/pages/mediacentre/press_releases/pr_976_en.html). Their press release says:

The world experienced unprecedented high-impact climate extremes during the 2001-2010 decade, which was the warmest since the start of modern measurements in 1850 and continued an extended period of pronounced global warming. More national temperature records were reported broken than in any previous decade, according to a new report by the World Meteorological Organization (WMO).

The report, The Global Climate 2001-2010, A Decade of Climate Extremes, analysed global and regional temperatures and precipitation, as well as extreme events such as the heat waves in Europe and Russia, Hurricane Katrina in the United States of America, Tropical Cyclone Nargis in Myanmar, droughts in the Amazon Basin, Australia and East Africa and floods in Pakistan.

The decade was the warmest for both hemispheres and for both land and ocean surface temperatures. The record warmth was accompanied by a rapid decline in Arctic sea ice, and accelerating loss of net mass from the Greenland and Antarctic ice sheets and from the world’s glaciers. As a result of this widespread melting and the thermal expansion of sea water, global mean sea levels rose about 3 millimetres (mm) per year, about double the observed 20th century trend of 1.6 mm per year. Global sea level averaged over the decade was about 20 cm higher than that of 1880, according to the report.

The WMO report charted rising atmospheric concentrations of greenhouse gases. Global-average concentrations of carbon dioxide in the atmosphere rose to 389 parts per million in 2010 (an increase of 39% since the start of the industrial era in 1750), methane to 1808.0parts per billion (158%) and nitrous oxide to 323.2 parts per billion (20%).

“A decade is the minimum possible timeframe for meaningful assessments of climate change,” said WMO Secretary-General Michel Jarraud. “WMO’s report shows that global warming was significant from 1971 to 2010 and that the decadal rate of increase between 1991-2000 and 2001-2010 was unprecedented. Rising concentrations of heat-trapping greenhouse gases are changing our climate, with far-reaching implications for our environment and our oceans, which are absorbing both carbon dioxide and heat.”

“Natural climate variability, caused in part by interactions between our atmosphere and oceans – as evidenced by El Niño and La Niña events – means that some years are cooler than others. On an annual basis, the global temperature curve is not a smooth one. On a long-term basis the underlying trend is clearly in an upward direction, more so in recent times” said Mr Jarraud.

Of note are the qualifiers in the report (and hence the reason for the title of the post):

It is still  not yet possible to make a definite link between the increase in the observed losses with an  increase in the frequency and intensity of extreme events. Other factors come into play, such  as increased vulnerability and exposure of populations and the increase in the number of  reports of disasters. Nevertheless, it is worthwhile to note a large increase of loss of life from  heat conditions, particularly in two unprecedented extreme heatwaves that affected Europe  in summer 2003 and the Russian Federation in summer 2010.
Due to the lack of complete datasets on several other types of extreme events, it was not possible to perform robust trend analysis. The lack of these datasets is currently being  addressed by the WMO Commission for Climatology Expert Team on Definitions of Extreme Weather and Climate Events. The Team is working on a harmonized approach worldwide for  better identification and assessment of these events.

Moreover, the Expert Team on Climate Change Detection and Indices has been working for  several years on developing simple climate indices that can be derived from daily data to  analyse the changes in the distribution characteristics related to key climate variables, i.e. temperature and precipitation.

Assessment of global warming is founded on multiple-year data analysis. A decade is the minimum possible time frame to detect temperature changes. Assessing the changes in the behaviour of extreme weather and climate events requires an even longer-term time frame because these events, by definition, do not happen frequently. It is important, therefore, to develop a more complete understanding of these events through enhanced data collection, data management and research.



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