probability

If the probability of was the same as the probability for PPM and °C, there would be per year instead of .

That is the same as per day or per hour.

## PPM = PARTS PER MILLION OF GREENHOUSE GASES

“PPM” is a unit used for measuring the CO2 concentration in the atmosphere. It stands for “parts per million,” and is used to denote the ratio of carbon dioxide molecules compared to all other molecules in the atmosphere.

## Explanation of degrees

Increase in global average temperature measured in degrees celsius (°C).

## About other risks

In order to better understand how serious global risks are you can compare the probabilities for different degrees of warming with the probabilities for other well known risks:

- Probability of a fatal flight accident on your next flight.

- Annual probability of being fatally struck by lightning.

- Annual probability of dying in a terrorist attack

## About databases

Probability estimates vary for different reports depending on basic assumptions and choice of climate models. In this menu you can select and compare different data sources and their probability estimates.