Even a 2 C rise above the pre-industrial level would be outside the range of temperatures experienced by human civilization.

Presently, the planet is at a pre-Industrial level of technology.

Only a handful of people will live through this, and they'll be thrown back to a pre-industrial level.

Many experts believe that late in the next century, concentrations of the gas will be double their pre-industrial levels.

By 2100 we could reduce C02 levels to pre-industrial levels.

The international community has agreed to limit global warming to 2 degrees Celsius above pre-industrial levels.

An absolute increase of more than 2C above pre-industrial levels will, said the report, lead to "rapid, unpredictable and non-linear responses".

The decline in industry during the 20th century saw the population fall to pre-industrial levels.

Durban alone will not limit global warming to 2 degrees above pre-industrial levels.

These are the consequences that a mere 1C of warming above pre-industrial levels have wrought.