The combined global land and ocean surface temperature for January-October this year was +0.63°C above the 20th century average of 14.1°C and tied with 1998 as the warmest January–October period on record, according to new report State of the Climate — Global Analysis,  in October.


Figure 1: Temperature anomalies October 2010 with respect to October periods 1961-1990

The data indicate mean temperature changes in the Arctic of up to +5oC relative to the 1961-1990 base period, leading to progressive loss of Greenland ice sheet and Arctic sea ice, which in October 2010 was 17% less than during October periods of 1979-2000.

The report was published by National Climatic Data Centre (NCDC), National Oceanic and Atmospheric Administration (NOAA).

Consistent with elevated radiative forcing by greenhouse gases in the atmosphere, leading to high temperatures, strong evaporation and abrupt precipitation events, 2010 has seen a string of extreme weather events, including heat waves and fires (Russia), severe droughts (Brazil, Mexico), cyclones (US, Caribbean) and floods (Pakistan, western China, Australia).


Figure 2: Selected significant climate anomalies and events, October, 2010

That extreme weather events are increasing in frequency and intensity is shown in figure 3, showing the number of cyclones increased by a factor of about 2 and floods by a factor of about 3.


Figure 3: Trends in climate disasters compared with earthquakes
showing tripling of the annual frequency of floods and doubling of frequency of cyclones.

Mean global high temperatures persisted despite a prevalence of La-Nina conditions, which resulted in below-average temperatures across the equatorial Pacific.

Thanks to the surrounding oceans Australia has been mostly benign in terms of temperature. The decrease in mean temperatures in Australia (figure 1) is related to the increased rainfall, clouding and evaporation/cooling effects. For Australia the year 2010 (to November) ranks in the top 10 for rainfall due to a confluence of seasonal drivers — ENSO and IOD.

Much of the rainfall occurred as abrupt precipitation events, less beneficial and often destructive as compared with gentler Mediterranean-type precipitation. A significant drying up continues in south-western Australia, which had record low winter season rainfall, continuing a trend that began around the 1970s. This year south-western WA had little inflows into its dams.

The rise in the frequency and intensity of extreme weather events around the world implies models suggesting gradual climate transitions, such as projected by the IPCC-2007, require revision in terms of the effects of tipping points, consistent with recent research.

“The growth rate in emissions is going to make it increasingly difficult for us to constrain climate change to levels of around 2 degrees of warming above the pre-industrial temperatures,” says a new report by the Global Carbon Project

According to Professor Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research, +2 degrees may result in tipping points.

Ignoring reports by the world’s major climate science organisations (NASA/GISS, NCDC, Hadley-Met, Potsdam, BOM, CSIRO), governments continue to consider the issue almost exclusively in economic dollar terms, the ultimate Faustian bargain.

Most are oblivious to the calamitous consequences of inaction or of limited action falling short of arresting climate change. Current negotiations regarding climate mitigation and debates regarding carbon tax versus CPRS schemes, ignore the implications of the rise in extreme weather events.

Extensive media cover-up, coupled with well-funded climate denial campaigns, are on the rise. Emergency climate mitigation measures, including draw-down of atmospheric CO2 using soil biochar, chemical sequestration and extensive reforestation, may have a chance of slowing runaway global warming.

*This first appeared at the Rooted blog.