Understanding climate change
Climate change or global warming refers to a gradual increase in the global average air temperature at the Earth's surface. The majority of scientists now agree that global warming is taking place and that it is caused by increases in the concentration of 'Greenhouse Gases' in the atmosphere. The most important single component of these greenhouse gas emissions is carbon dioxide (CO²). The major sources of emissions of CO² are power plants, motor vehicles and industry. Combustion of fossil fuels contributes around 80% to total world-wide man made CO² emissions.
How does Global Warming work?
The earth's atmosphere is made up of several gases, which act as a 'greenhouse', trapping the sun's rays as they are reflected from the earth's surface. Without this mechanism, the earth would be too cold to sustain life as we know it. Since the industrial revolution, humans have been adding huge quantities of greenhouse gases, especially carbon dioxide (CO²) to the atmosphere. More greenhouse gases means that more heat is trapped, which causes global warming. Burning coal, oil and natural gas increases atmospheric concentrations of these gases. Over the past century, increases in industry, transportation, and electricity production have increased gas concentrations in the atmosphere faster than natural processes can remove them leading to man-made warming of the globe.
For the last 600,000 years atmospheric C02 concentrations have never risen above 300 parts per million. Throughout this time the planet has experienced climate change but never at the rate that it is currently experiencing it. It is broadly agreed by the scientific community that “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 387ppm to at most 350ppm.” Since NASA climatologist Dr. James Hansen said that in 2008, atmospheric CO2 has risen to 389.91ppm (source www.CO2now.org)
Recently, events that are consistent with scientific predictions about the effects of climate change have become more and more commonplace. The global average temperature has increased by about 0.5°C and sea level has risen by about 20 centimetres in the past century. 1998 was the hottest year since accurate records began in the 1850s, and ten of the hottest years have occurred between 1995 and 2009. Half a degree of warming may sound small, but due to a time lag of 40-50 years between emissions and warming, we have already committed the planet to a further 1.5°C of warming above pre-industrial levels. As the human population grows, the rate of CO2 emissions increases rapidly and it is estimated by the Inter-governmental Panel on Climate Change (www.ipcc.ch) that the planet could experience warming of upto six degrees over the next ninety years.
Official confirmation of global climate change came in 1995, when the IPCC, an officially appointed international panel of over 2,500 of the world's leading scientific experts found that, “the balance of the evidence suggests a human influence on the global climate.” It has been concluded that the temperature on this planet during this century has steadily risen with the higher concentration of carbon dioxide.
The past two decades have witnessed a stream of new heat and precipitation records. Glaciers are melting around the world. There has been a 50% reduction in glacier ice in the European Alps since 1900.
In Glacier National Park in Montana, USA glaciers are diminishing rapidly. The area of each glacier has been mapped by the National Park Service and the U.S. Geological Survey for decades. Comparing photographs taken in the mid-19th century with contemporary images provides ample evidence that the glaciers in the park have retreated notably since 1850. Repeat photography over the decades clearly shows that glaciers throughout the park such as Grinnell Glacier (shown below) are all retreating. The larger glaciers are now approximately a third of their former size when first studied in 1850.
Between 31 January 2002–5 March 2002 the Larsen B Ice shelf (below) collapsed and broke up, 3,250 km² of ice 220 m thick disintegrated in a single season. Prior to the break-up Larsen B had been stable for up to 12,000 years.
The evidence above is only the ‘tip of the iceberg’ (no pun intended) there is plenty more evidence relating to atmospheric CO2 levels and climate change. If you would like to know more click on the links below.
www.co2now.org - Real time data on atmospheric carbon dioxide concentrations
www.350.org - Environmental pressure group
www.ncdc.noaa.gov/paleo - National Climatic Data Centre for the National Oceanic and Atmospheric Administration
www.climatecrisis.net - Find out more about Al Gore's An Inconvenient Truth
www.marklynas.org - Web site for environmental author and journalist Mark Lynas
www.ipcc.ch - The UN Inter-governmental Panel on Climate Change.
www.metoffice.com/research/hadleycentre - The UK met office's climate research unit.
www.nerc.ac.uk/about/consult/debate/climatechange/summary.asp - Natural Environmental Research Council
www.wakeupfreakout.org/film/tipping.html - A short film about the impacts of climate change.
www.wmo.int - World Meteorological Organisation
www.e360.yale.edu - Environmental education at Yale university
Impacts on humanity
Climate change is set to have a huge impact on humanity over the next century with increased storms, flooding, drought, mass water shortage and billions becoming refugees. As people are forced into increasingly small areas of habitation to compete over the planets dwindling resources conflict, disease and famine are inevitable consequences.
We don’t have to choose the path of self destruction, if you want to know what the Isle of Man will do to deal with climate change then come along to the discussion.