Back in the summer of 2008 athletes from all over the world were getting together in China for the 29th edition of the Olympic Games. Just prior to the games inaugural ceremonies there were a lot of concerns about the air quality, the contamination, and the heat in Beijing. Many athletes wore face masks to prevent getting sick prior to their respective competitions. We might be asking ourselves, what does that have to do with climate change? As China and its neighbors economies grow, the need for more energy increases. In order to meet their energy demands, industries have to use fossil fuels for energy.
Fossil fuel burning accounts for 75% of the total global energy use (Ciserone, 2000, p. 1). When fossil fuels are burned, greenhouse gases are released into the atmosphere thickening the air, trapping heat and other pollutants increasing the chances for climate change thru human induced activities. Human activities promote the release of greenhouse gases into the atmosphere. Greenhouse gases cloud the atmosphere leading to a warming of the earth’s atmosphere. Climate change occurs as a result of atmospheric changes promoted by human activities.
As industrialized nations energy demands increase, the discharge of greenhouse gases like Carbon Dioxide (CO2), Methane (CH4), and Nitrous Oxide (N2O) increases thus contaminating the air and clouding the atmosphere. Since the beginning of the industrial era in 1750, the usage of fossil fuels for energy have increase more than 20 fold. However, this amount of energy is a lot less than the solar energy that is absorbed by the atmosphere. What makes the big impact is the release of human induced greenhouse gases. Thru these gases, the earth receives an additional 1% of the solar energy and it is growing (Ciserone, 2000, p. ). For example: Carbon dioxide is the most important anthropogenic greenhouse gas and its annual emissions have increased 80% between 1970 and 2004. These emissions come from fossil use in transportation, heating, and manufacture of household goods. Methane has increased as a result of agricultural practices, natural gas distribution and landfill related releases of the gas. Halocarbon gases have also increased. These gases were used extensively as refrigeration agents and were found to cause ozone layer depletion. Ozone is a greenhouse gas that is continually produced and destroyed by chemical reactions.
The release of these Halocarbon gases destroys the ozone layer and has caused the opening of an ozone hole over the South Pole. The characteristics of these greenhouse gases have been studied since the beginning of the 19th century. Changes in atmospheric concentrations of greenhouse gases and aerosols, land cover, and solar radiation alter the energy balance of the climate system (Climate Change for Policy Makers, IPPC, 2007). To explain how these gases affect the atmosphere a group of scientists (Fourier, Pouillet, Tyndall, Langley, Arrhenius) came up with a measure called radiative forcing.
In technical terms, radiating forcing is the change in net radiation at the tropopause or the boundary between the troposphere and the stratosphere. In other words, radiative forcing is the amount of solar infrared energy that is either returned back to earth or filtered thru the layers of the atmosphere back into space (Ciserone, 2000, p. 1). There are two types of radiative forcing: Positive and negative. Negative forcing is the complete return of solar infra-red energy back on to space after bouncing from the surface of the earth.
Positive forcing is the return to the earth of the same solar infra-red energy but from the greenhouse gas cloud in the tropopause. The thicker the cloud, the more positive forcing thus is increasing the average temperature on earth. From all the greenhouse gases, carbon dioxide has caused the largest positive forcing with the release of halocarbon gases in close second. But not all radiative forcing is a direct effect of human activities. There are natural forcings as well. Natural forcing comes from solar changes and volcanic eruptions on earth.
Solar energy heats up the atmosphere and can affect the abundance of some greenhouse gases. Volcanic eruptions can create negative forcing by increasing the concentration of sulphate aerosols in the stratosphere. But these natural induced forcing have not changed the earth’s climate significantly. In the other hand, solar and volcanic events would likely have produced cooling instead of warming. Therefore, the radiative forcing from human activities is much more influential to current and future climate change than the estimated forcing from natural processes.
Because of that anthropogenic influence the earth’s climate and life cycle is in constant change. Science shows that human influence extends beyond average temperature increase to other aspects of the climate. These influences have contributed to changes in wind patterns affecting tropical storm temperature and patterns, increased the risk of heat waves, contributed to sea level rise during the late 1900’s, increased the frequency of heavy precipitation events, and variations in winter and summer night and day temperatures.
Due to these and other climatic changes the warming has been discovered to be greatest over land and at most high northern latitudes. The reduction of snow covered areas, and the decrease of sea ice extent is also a major indicator of climate change. Arctic late summer sea ice disappears almost in its entirety during warmer summer months creating a lifecycle imbalance in the Polar Regions. In both of these regions there is strong evidence of the ongoing impacts of climate change on terrestrial and fresh water species, communities and ecosystems (IPCC 2007 Chapter 15, p. 5). Studies show that such changes will continue with implications both in the region and globally. Sub-regions of the Arctic and Antarctic have shown the most rapid rates of warming in recent years. Substantial environmental impacts of climate change show profound regional differences both within and between the Polar Regions, and enormous complexity in their interactions. The impacts of this climate change in the Polar Regions will exceed the impacts forecast for many other regions and will produce feedbacks that will have globally significant consequences.
Some of these consequences are: The decrease in the amount of the solar energy reflected back to space leading to a more intense surface warming increasing the melting of Arctic ice and also increasing regional precipitation. This will add freshwater to the oceans, and potentially affect the earth’s ocean currents. The thawing of the permafrost (a layer of soil or bedrock at a variable depth beneath the surface of the earth in which the temperature has been below freezing continuously from a few to several thousands of years) which leads to the release of greenhouse gases like methane and carbon dioxide.
Last but not least are the melting of the polar ice sheet and glaciers. Global climate models suggest that the contribution of Arctic glaciers to global sea-level rise will accelerate over the next 100 years. By the end of the 21st century, the melt of these glaciers will have contributed to a rise of roughly 4 to 6 centimeters. Some climate models project that local warming over the Greenland Ice Sheet will eventually lead to its complete disappearance, with a resulting sea-level rise of about 23 feet. But how do all of these consequences affect us?
Sea level rise is projected to have serious implications for coastal communities and industries, islands, river deltas and harbors and the large fraction of humanity living in coastal areas worldwide. It will increase the salinity of bays and estuaries increase coastal erosion, and especially where coastal lands are soft rather than rocky. Extensive coastal lowlands and delta areas contain important ecosystems that will be affected by rising sea levels. Wetlands will be forced farther inland, and the incidence of coastal floods will increase.
Furthermore, and due to global warming tropical regions will experience climate change as well. Stronger and more frequent tropical storms, extended drought, stronger heat waves, are more likely to happen. Model projections have linked these changes to the warming induced by human activities. Despite some limitations, there is sufficient evidence to conclude that over the last few decades the warming induced by human activities has had a measurable impact on many physical and biological systems.
Temperature increases have affected agricultural and forest management, the number of heat related deaths, and the spread of disease such as malaria. The spread of diseases like Malaria are more likely to happen in under developed countries that don’t have the means or have less capacity to adapt to these changes. Climate change already has a measurable impact on many natural and human systems. Effects are projected to increase in the future and to be more severe with even higher increases in temperature.
Adaptation measures are already being implemented, and will be essential in order to address the expected consequences (Climate Change for Policy Makers, IPPC, 2007, p. 11). There is, however a limit to adaptation. Mitigation measures will also be needed in order to reduce the impacts. Mitigation measures that aim to reduce greenhouse gas emissions can help avoid reduce or delay many impacts of climate change. Policy instruments could create incentives for producers and consumers to significantly invest in products, technologies and processes which emit less greenhouse gases.
Without new policies, greenhouse gas emissions will continue to grow over the coming years. World wide investments and deployment of mitigation technologies, as well as research into new energy sources will be necessary to achieve a stabilization of the concentration of greenhouse gases in the atmosphere. Current warming trends are unequivocal. It is very likely that greenhouse gases released by human activities are responsible for most of the warming observed in the past fifty years. The warming is projected to continue and to increase over the course of the 21st century and beyond.