Did the earth get hotter? Yes. Is it common? Yes. Since 1900, the average temperature has increased by 0.7 degrees Celsius. Over the past 300 years, the temperature has risen by about 0.6 °C. Of course, we didn’t have cars and electricity for most of this time. So the great climate debate is not if the earth is getting hot or not but if or how we earthlings are having an impact on the global climate.
The first person to suggest climate change due to human activities was made by Swedish scientist Svante Arrhenius, in 1896. However, American geophysicist Roger Revelle is credited for making the first high-level global warming predictions, in 1965. Now, everyone from grandma to the United Nations is in on the debate. The only ones sitting out are the bookies, perhaps because long term predictions about the climate are too risky.
Hot and cold cycles of earth
65 million years ago the earth was hotter than now. 15,000 years ago there was the Ice Age, with temperatures about 7 °C colder than today. From 800 to 1300 AD it was hotter again, melting the sea ice, allowing Vikings and other groups to cross oceans and colonize lands; it is referred to as the Medieval Warm Period. But from 1300 to 1900 it was colder again, that period dubbed the Little Ice Age. And then, as said, it got hotter again.
2006 was the warmest year on (recent accurate) record with an average temperature of 12°C (55°F) which is 1.2°C (2.2°F) above the 20th Century mean. But 2007 was the coldest in much of the Southern Hemisphere with Australia and South America recording record low temperatures. Europe and North America experienced cold waves during 2009 with record rainfalls in many areas.
Between 1870 and 1993, global sea levels rose at an average rate of 1.7 mm per year. Between 1993 and 2003, they rose by 3.33 mm per year. This is mainly due to the polar ice caps melting – they have shrunk by one third over the past 150 years. Yet, in October 2009 the sea ice extent in the Southern Hemisphere was 2% above averages of the past decade.
The human factor
So, compared with solar activity and the general climate cycles of earth the rise in temperature should be halting about now and turn toward another little ice age. But here is the problem: according to IPCC (Intergovernmental Panel on Climate Control) the impact of human activities is some ten times that of natural and solar factors. The fear is that our influence will cause irreversible catastrophes.
The world’s oceans are believed to absorb about half of the total carbon emissions from human activities and those from cows. The world’s tropical forests absorb the equivalent of the total carbon dioxide emissions from the United States. Fortunately we do not drink seawater – not even fish do, they get their water intake by eating other fish and osmosis – but we massively can reduce the chopping down of trees by buying less luxury wooden items, we can also drive less and walk more, and we can throw our weight against the great global warming finance swindle.