Wednesday, February 26, 2014

Climate Change ?

"Climate is what you expect; weather’s what you get” 

Low temperatures are predicted to fall below zero again tonight, marking the 48th sub-zero low for Green Bay area this winter, tying the all-time record (48 days in the winter of '76-'77).  And with even lower temperatures expected tomorrow night, a new record will be set.  Could it be global warming isn't happening as quickly as some have predicted?  Or do we need to look beyond the recent cold timperatures in our litttle corner of the world, to consider all the recent extreme weather events.

And according to the UN's World Meteorological Organisation (WMO), which monitors global weather, the first six weeks of 2014 have seen an unusual number of extremes of heat, cold and rain – all around the world at the same time, with costly disruptions to transport, power systems and food production. There have been heatwaves in Slovenia and Australia, snow in Vietnam and the return of the polar vortex to North America. Britain has had its wettest winter in 250 years but temperatures in parts of Russia and the Arctic have been 10C above normal. Meanwhile, the southern hemisphere has had the warmest start to a year ever recorded, with millions of people sweltering in Brazilian and southern African cities.

Further support for global warming can be found in the "headine statements" published on September 27, 2013, by the Intergovernmental Panel on Climate Change (IPCC) as part of the organization’s fifth assessment report:

  • 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.
  • 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 30-year period of the last 1400 years (medium confidence).
  • Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence). 
  • Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent (high confidence).
  • The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence). 
  • 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% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification.
  •  It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. 
  • Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions. Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped.  

Polar ice cap melting
The Intergovernmental Panel on Climate Change (IPCC) estimates that the global average sea level will rise between 0.6 to 2 feet (0.18 to 0.59 meters) in the next century (IPCC 2007). However, climate models, satellite data, and hydrographic observations demonstrate that sea level is not rising uniformly around the world. Local sea level change, which is of more direct concern to coastal communities, is a combination of the rise in sea level and the change in land elevation.  Some areas of the country, such as areas within Alaska, are actually experiencing a lowering of local sea level due to regional uplift of land caused by the retreat of glaciers. Meanwhile, areas along the Gulf of Mexico coast are experiencing land subsidence at varying rates, accelerating the rate of seal level rise (NOAA 2010c). The map below displays local trends in sea level, with arrows representing the direction and magnitude of change. 

"The debate is settled. Climate change is a fact. And when our children’s children look us in the eye and ask if we did all we could to leave them a safer, more stable world, with new sources of energy, I want us to be able to say yes, we did."
-Barack Obama

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