In this post some more facts are shown in continuation with the last post..
Sea Level Rise
As we all know, when water warms it expands. Add this to water melting from glaciers and the arctic and you will see a measurable amount of sea level rise. While sea level rise by all accounts has been occurring for as long as we can tell, what is of particular interest is the rate of change that has been occurring. From 1870 to 1992, the average sea level rise has been 1.7 mm. As the chart below indicates, those rates have nearly doubled starting in 1993.
(click on the photographs to enlarge)
Carbon Dioxide Levels
Carbon dioxide (CO2) in our atmosphere has been around longer than mankind. As we all know, CO2 is part of a natural process involving plants and animals as well as volcanic eruptions. Manmade CO2 comes from the burning of fossil fuels used in energy plants, manufacturing plants and the various modes of transportation we use. The chart below shows the levels of CO2 measured in the Earth’s atmosphere over the past 400,000 years. Everything appears quite normal up until about 1950 where instead of following the cycle of upward and downward trends, the levels increased beyond any point in history and continued upward. April 2010 set yet another record of atmospheric CO2 at 392 ppm.
(click on the photograph to enlarge)
Now we have four factual indicators of warming. The issue is really with last one, the CO2. What is causing the increase in CO2? That is the center of the debate as to whether we are causing the rising CO2 levels or is nature doing this?
As we all know by now, CO2 comes from nature and from man. If the Earth warms, CO2 from nature increases as well. When there is less ice in the arctic regions, the Earth will absorb more of the Sun’s energy, which will create more warming since the oceans will release more CO2 . This cycle is known as a positive feedback. As permafrost regions on the Earth begin to melt, more greenhouse gases including methane which is known to have even a bigger impact on the greenhouse effect, are released from the soil that was once frozen, again this is positive feedback.
Scientists are tracking solar output from the sun to determine if change in the sun’s output, known as solar irradiance, is a contributing factor to global warming and the subsequent climate change. These studies are important as they may help us understand the influence the sun’s energy has in creating the recent warming. While there has been no conclusive evidence to date, it merits closer observation and study.
So, what is causing CO2 levels to continue to rise? We know that we are definitely putting more CO2 into the atmosphere than we ever have. As countries like China and India go through their new found industrial growth, we continue to release more CO2, while it would make sense to point at these man made increases as the primary culprit, it is simply not that easy. Unfortunately regulating CO2 levels across the globe is a daunting task. What agency will monitor what countries and businesses are doing? In an already poor global economy, what is the cost of making these changes? Will the changes even have an impact on reducing CO2 levels? While we continue to debate, what will the cost be of doing nothing? Should we act now and wait for science to prove definitively that nature or man causing the global warming? Do we wait until we know for sure?
At this point, we have more questions than answers and anyone who says otherwise is doing so for reasons outside of getting to the scientific truth. We know the Earth is warming. The factual evidence cannot be disputed. If you had the power today to decide what path we should take, what would you choose? Do nothing until science has been proven, or begin a program that reduces the amounts of CO2 that man is putting into the atmosphere? What would you do to change the world we live in..