Climate change: What's the big deal?

River Thames frost fairs were held on the tideway of the River Thames at London between the 15th century and early 19th century, during the period known as the Little Ice Age, when the river froze over.

During the Great Frost of 1683–84, the worst frost recorded in England, the Thames was completely frozen for two months, with the ice reaching a thickness of 11 inches (28 cm) in London. Solid ice was reported extending for miles off the coasts of the southern North Sea (England, France and the Low Countries), causing severe problems for shipping and preventing the use of many harbours.

why can't the scientists prove climate change 100%

First of all, it is worth bearing in mind that any data on global temperatures before about 150 years ago is an estimate.

There have been several "hothouse earth" periods when the temperature exceeded those we experience today. The warmest was probably the Paleocene-Eocene Thermal Maximum (PETM), which peaked about 55 million years ago. Global temperatures during this event may have warmed by 5°C to 8°C within a few thousand years, with the Arctic Ocean reaching a subtropical 23°C.

The warming, which lasted 200,000 years, was caused by the release of massive amounts of methane or CO2. It was thought to have come from the thawing of methane clathrates in deep ocean sediments.

Since then, the Earth has cooled. For the past million years or so, the climate has switched between ice ages and warmer interglacial periods with temperatures similar to those of the past few millennia.

What is clear from the study of past climate is that many factors can influence climate: solar activity, oscillations in Earth's orbit, greenhouse gases, ice cover, vegetation on land (or the lack of it), the configuration of the continents, dust thrown up by volcanoes or wind, the weathering of rocks and so on.

Many of the world's politicians have chosen to focus on greenhouse gas, because in that way, they can also focus on tax hikes. In this way they can raise money, when they are desperately trying to increase taxes to pay for an accumulation of ill advised projects that they have signed off.

Energy Secretary Ed Davey last night launched an attack on ‘dangerous and destructive’ climate change sceptics.

The Liberal Democrat Cabinet minister accused ‘publicity-seeking’ critics of ‘selectively misreading’ the evidence.

If that is the case Mr Davey, why can’t you produce the evidence that proves your theory 100%.