For the last 2.5 million years, global temperature has shifted between cold glacial periods that last for around 100 000 years, and warmer interglacial periods that last for around 10 000 years. Right now we are in an interglacial period. 20 000 years ago the Earth was cold. Around 15000 years ago it started to warm up, this was the end of the last glacial period. Over the last 10 000 years the climate has been warm with minor fluctuations, however over the last 1000 years the climate has been fairly constant with small fluctuations in annual temperature. Over the last century global temperature has increased rapidly. This is called global warming; there has been a sharp rise in average temperature, 0.7oc between 1900 and 2000. The temperature increase over the last century has been very fast. There is a consensus among scientists that the changes in climate over the last century are a result in human activities (anthropogenic causes), including Al Gore, as shown in the statement which I agree with. I think the majority of global warming is due to humans therefore it is our right to try and find solutions to diminish global warming as much as we can.
There is a scientific consensus that the recent rise in global temperature (global warming) is caused by human enhancement of the greenhouse effect, where greenhouse gases absorb outgoing long-wave radiation, so less is reflected back to space and is essential for keeping the planet warm. However, too much greenhouse gas in the atmosphere means too much energy is trapped and the planet warms up. One of the key findings in the IPCC report is the attribution of more than half the increase in global surface temperatures from 1951-2010 to human activities, underlining the dominant role of fossil fuel burning as a