History+of+Climate+Change

media type="youtube" key="coeE3fkP22M" height="344" width="425" align="right" After watching the first video take a look at Climate Change 2563. Which shows what is or could happen in the future. Saying that the change in climate will go as people expect with widespread drought. But not expected is that in some regions a new ice age well begin. Because of all the storms cloud cover well prevent the suns rays from getting to earth. These regions well begin the develop ice cover that the sun cant thaw. In essence the entire earth well revert back to its inhabitable state, waiting to heal its self. Change of climate through eras: Climate change is a natural occurance that has happened throughout time. As seen in the picture to the left, the earth has gone through change mutiple times, the most famous of which is the Ice Age.

Humans have reacted to climate change in various ways. Here's a brief summary of human reactions to climate change. It's an excerpt from [] and is written by Spencer Weart, the author of the book __The Discovery of Global Warming__.

"From ancient times people suspected that human activity could change the climate. The discovery of ice ages in the distant past proved that climate could change all by itself. In 1896, a Swedish scientist published a new idea: as humanity burned fossil fuels such as coal, which added carbon dioxide gas to the Earth's atmosphere, we would raise the planet's average temperature. Scientists found good reason to believe that our emissions could not change the climate—major change seemed impossible except over tens of thousands of years. In the 1930s, people realized that the United States and North Atlantic region had warmed significantly during the previous half-century. Scientists supposed this was just a phase of some mild natural cycle, with unknown causes. G.S. Callendar insisted that greenhouse warming was on the way. In the 1950s there was a sharp increase of government funding, especially from military agencies with Cold War concerns about the weather and the seas. The new studies showed that, contrary to earlier crude estimates, carbon dioxide could indeed build up in the atmosphere and should bring warming." It appeared that grave climate change could happen, and in the past had happened, within as little as a few centuries."

In 1896 Svente Arrhenius showed that doubling the amount of carbon dioxidem would cause the glaobal temperature 5-6 degrees. Yet this was ignored, because scientists at the time were obssesed with explaning the ice ages.

The idea of global warming was ignored until 1938, when Guy S Callender suggested that the warming trend revealed in the 19th century had been caused by a 10% increase in atmospheric carbon dioxide from the burning of fossil fuels. Scientists thought that all the CO2 had dissloved into the ocean, but was later proven wrong by Hans Suess and Roger Revelle in 1957, who showed a complex buffering system that wouldn't allow sea water to hold in large amounts of atmospheric CO2.

The graph above shows the change in climate over centuires and through eras. The graph below is more recent, and has probably been seen before. It shows a more recent look at the change in the average temperature, it is with in the past 100 to 150 years. Showing a steady increase until the mid 1900's when it shoots up.

A broad overview of the Earth's climate: __34,000,000 years ago:__This time period was the shift from the Eocene epoch to the Oligocene epoch. The climate generally shifted from hot to cold, a change that occurred most likely because of continental drift. __70,000 years ago:__ At this time, Homo sapiens were present, as were Homo neanderthalensis (Europe) and Homo floresiensis (Indonesia). The climate was not reliable, however, and a possible eruption of Mount Toba in Indonesia could have caused several years of very cool weather, which subsequently would impact human populations. __21,000,000 years ago:__ The ice age took place around this time—most of North America and Europe were covered by ice. Ever since the LGM (Last Glacial Maximum aka the Ice Age) the climate has been warming. __10,000 years ago:__ This climate allowed homo sapiens to thrive. It continued to warm, and towns, cities, and human population all grew. Other than volcanic eruptions, which cause the climate to temporarily cool, the climate has been warming since then. __1,000 years ago:__ Most of the volcanic eruptions have happened over the last 700 years. During this time period were many volcanic eruptions which cooled the climate, but only temporarily. __150 years ago:__ This is the time of the industrial revolution. Humans began burning coal and oil in much larger amounts. Because of the gradual warming of the climate (due to the huge amounts of greenhouse gases in the atmosphere), volcanic eruptions had a much shorter effect on climate than they had previously. __10 years ago:__ At this time it was realized that climate change can, and was, happening faster than imagined. World leaders began calling for controls on greenhouse gas emissions. __Present Day:__ Today, glaciers are retreating and there is a slowing of the thermohaline circulation in the Atlantic Ocean.



It has been discovered using various techniques that the Earth’s climate warms up temporarily about every 100,000 years. This is called an interglacial period and from 15,000 to 20,000 years. The last ice age on Earth was 18,000 years ago, which means, using this estimation, the Earth will be cooling again in 2,000 years. But the climate change being feared is not global cooling; it is global warming. Global temperatures have been increasing since 1860, the end of the industrial revolution when the world began burning larger and larger amounts of fossil fuels. It is unclear to scientists what will happen in the future—whether the Earth will go into another ice age, or whether the climate will blaze its own trail, contrary to data from the past, and warm up even more.