Climate and global warming facts to ponder
The average amount of sunlight energy reaching the Earth's outermost atmosphere today is equivalent to a little bit more energy than three and a half 100 watt light bulbs turned on above every square metre of Earth's surface.
Without a protective atmosphere, scientists estimate that the average temperature on Earth would be -18 C instead of the current 15 C because the energy would bounce out almost as fast as it was coming in from the sun.
The concentration of CO2 in the atmosphere, the main greenhouse gas released by human industrial activities, has increased 35 percent since the beginning of the industrial revolution.
The long term effects of increasing accumulation of greenhouse gases, mainly CO2 in the atmosphere include:- A rising global temperature
- Melting polar icecaps with a corresponding increase in sea levels
- Melting permafrost
- Change in precipitation patterns with many dry places getting dryer
- Increased occurrence and intensity of storms (hurricanes and tornados)
- More forest fires
- Introduction of new diseases and the spread of diseases to other locations
It is estimated that Earth's average temperature has increased 0.7 C over the last century.
Human activities currently are releasing approximately 7 billion metric tons of carbon (in the form of CO2) into the atmosphere (mostly from burning fossil fuels) per year adding to the 750 billion tons that is already there.
Only a little less than about half of the 7 billion tons annual human up-load of CO2 ends up staying in the atmosphere. Where does the rest go? Some is absorbed by terrestrial and marine plants, some dissolves in the ocean. The ocean removes about 2 billion tons. It is obvious that the forests of the world are important in removing much of the 1 billion tons estimated to be taken up by terrestrial plants. Exactly where this sequestered CO2 goes is still a mystery.
It is estimated that the release of all the stored carbon in the boreal forests around the globe would increase the current CO2 content in the Earth's atmosphere by 50 percent.Recent analysis of annual snow layers in Arctic glaciers spanning back more than 200,000 years indicates that there have been very abrupt changes in climate leading some climatologists to theorize that climate does not change gradually but instead changes by passing a threshold and flipping into a new stabilized pattern with radical rapid consequences when the threshold is breached. No one knows if today's human caused global warming is bringing the current climate patterns to a threshold change.
Without any controls on greenhouse gas emissions, experts predict that the mean global temperature will rise by about 1.2 degrees C by 2050 and 1.9 degrees C by the year 2100. Such a change in global temperature has not been experienced on earth since 150,000 years ago.
