What is global cooling?

Answer 1

There was a slight cooling around the middle of the 20th Century caused by the amount of pollution particles in the air. These were reflecting the sun's rays. When Clean Air Acts began to take effect around the world the air became cleaner and the cooling disappeared.

Answer 2

The phrase 'global cooling' is the exact opposite of 'global warming'. Though historically one tends to follow on from the other (that is, global temperature changes are often cyclical), if by 'lead to' you imply a causal link, then that would be incorrect.

At the moment, the planet is experiencing global warming [see link titled "Global Climate Change" in the "Sources and Related Links" section below] which, without human activities, would eventually change to global cooling due to processional changes in the orbit and tilt of the Earth in relation to the sun. However, although cooling was once predicted by some scientists within the next few hundred years, thanks to all the CO2 we're putting into the atmosphere (creating 'the greenhouse effect'), there's no way that global cooling can now happen for tens of thousands of years.

If you're referring to the current cold spells being experienced in some higher latitude countries (the UK, Canada, Northern USA, for instance), then that can be called regional 'cooling', but it's not global cooling. The warming in the Arctic which is causing the sea ice to melt more each year is also affecting the jet stream, causing it to meander and move more slowly. At times this is allowing cold Arctic air to travel further south, and for longer periods, than would normally be expected and might affect average yearly temperatures in areas like the UK. The article in the "Sources and Related Links" section below titled "Regional Cooling" explains how this regional cooling works:

Localised cooling effects caused by global warming redistributing heat are very new and work is ongoing to understand and predict them.

Answer 3

There are a number of potential causes of global cooling. The two main causes are thought to be the heavy use of sulphate aerosols throughout the 20th century and changes to the tilt of earths axis altering the orbital path of the Earth.

Answer 4

It is when heat from the sun comes into the atmosphere and the green house gasses trap the heat in and it slowly heats the Earth.

Answer 5

Global warming does not cause global cooling. Both global warming and cooling are the results of changes in the amount of the sun's energy retained by the planet. One does not cause another.