Global Warming History
Over time people have suspected that human activity could change the climate. For example, in the 19th century many Americans believed that cutting down forests brought more rainfall to a region. The discovery of ice ages in the distant past proved that climate could change all by itself, and radically.
This raised questions about what caused these changes. Was it variations in the heat of the Sun? Volcanoes erupting clouds of smoke? The raising and lowering of mountain ranges, which diverted wind patterns and ocean currents? Or could it be changes in the composition of the air itself?
In 1896 a Swedish scientist and Nobel Laureate, Svante Arrhenius, was studying fossil fuel combustion in Sweden and the prediction that the burning of such fuels would eventually lead to the process of global warming. Svante Arrhenius recognized that temperatures on the earth’s surface were related to carbon dioxide levels in the atmosphere. Arrhenius studied global warming to find out the average surface temperature of earth. He researched the possibility that doubling the carbon dioxide in a greenhouse effect would raise the surface temperature by five degrees Celsius. He also concluded that human activities could be to blame for future global warming. His focus, though, was on how much carbon dioxide would have to be taken away to cause global cooling.
In the 1930s, scientist realized that the United States and North Atlantic region had warmed significantly during the previous half-century. Most suggested this was a phase of some mild natural cycle, with unknown causes. One however, the amateur G.S. Callendar, insisted that greenhouse warming was on the way. Whatever the cause of warming, it was not thought of as a problem.
Over the next few decades, scientists developed ways to measure the Earth’s climate and devised mathematical models to better analyze global temperature. From late in the 1950’s to early in the 1960’s, Charles Keeling produced curves of the concentration of carbon dioxide in the atmosphere. He showed the scientific community that the earth had gone through 32 distinct weather variations. It had previously been thought that there had only been four. This led to a steady rise in the belief that human activity was dramatically effecting the environment. Scientific studies began to predict that increased carbon dioxide emissions, due to increased use of fossil fuels, would trigger an outbreak of global warming.
In 1992,the United Nations Conference on Environment and Development passed a declaration, which was agreed to by more than 150 nations, committing themselves to reducing carbon dioxide emissions in their countries. In 1994, the United Nations Panel on Climate Change then asserted that global warming was a major threat and that nations needed to enact drastic changes in order to negate the effects of global warming. This announcement led to the development of the Kyoto Protocol, an international agreement to fight global warming, which called for countries to reduce their emission of greenhouse gases effectively from 2005. The treaty was signed and ratified by 125 countries. However, the United States, which is estimated to be the world’s largest producer of greenhouse gases, refused to sign the treaty.
In the 2007 Bali Climate Agreement, world leaders committed to work toward reaching a post-2012, post-Kyoto global climate agreement by December 2009 in Copenhagen. The 14th Conference of the Parties in Poznan is the half-way point on the road to Copenhagen, and many participants are anxious to move quickly to ensure a new global agreement can be reached according to the proposed timetable. At the same time, major developments have taken place outside the scope of the UN climate talks since Bali.
In November, U.S. President-elect Barack Obama pledged that the United States will work toward capping its emissions and become an active participant in global climate talks after he takes office.
This removes a major roadblock to reaching a new global climate agreement, but some actions will require the support of U.S. lawmakers, so it remains unclear what form U.S. leadership will take. At the same time, a global credit crisis has stirred up new hopes and fears about the potential risks and rewards of investing in clean technologies. Skeptics say this is no time to make major investments in clean technologies, but President-elect Obama has said that is precisely what the United States will do, and on a scale large enough to usher in a new ‘green’ economy.
Thus Poznan is laden with conflicting expectations. On the one hand, participants are eager to respond to the urgency of climate change by reaching agreements that will lead to a post-Kyoto global climate treaty in 2009. On the other hand, the rules of the game have dramatically changed. It is in this context that EDF calls on world leaders to keep the focus in Poznan on the only true measures of success. Any new global climate treaty must invite broader participation from all nations -each according to its needs and abilities — and also meet the ultimate test of reducing global greenhouse gas emissions fast enough to stop global warming below 2ºC. EDF
