§ Mr. Stoddart
asked the Secretary of State for Defence what are the views of the Meteorological Office on the imminence of a new ice age; and what technical advice it has made available on this question.
§ Mr. John
I am advised by the scientists in the Meteorological Office that there have been no changes in the climate, or in factors affecting it, in recent years which suggest that an ice age might be imminent. Over the last million years there have been periods of extensive ice cover in the Northern Hemisphere, lasting altogether for more than half this time. These glacial periods have been separated by interglacial periods such as the present 441W lasting probably between 10,000 and 40,000 years, during which the permanent ice was restricted to the Arctic. The causes of ice ages are unknown, though there are a number of theories, none of which is adequately proven. Since, however, ice ages have occurred several times already, it is to be expected that natural causes will at some stage bring about another, probably some time in the next few thousand years.
The BBC television programme "The Weather Machine" of 20th November may have given a false impression of the imminence of a new ice age because it gave prominence to two new and, as yet, incompletely substantial ideas, namely (a) that the interglacial periods were shorter than previously thought—namely, around 10,000 years—and (b) that their onset was relatively rapid, taking place over a few centuries. Although the present interglacial period has already lasted 10,000 years these ideas do not necessarily imply that an ice age is imminent, as the time scale of change is still very long in human terms.
In recent decades there have been many small variations in climate which, in the British Isles, have led to temperature changes of less than 1°C and, in the semi-arid regions of the world, to more significant rainfall fluctuations. Both in the British Isles and averaged over the whole world the first 40 years of the present century were a little warmer than the previous century and there has on average been some decline of temperature in more recent years.
Viewed generally, however, the climatic fluctuations in recent years have been no greater than those experienced in recent centuries, and there is little to suggest that extreme weather events are more frequent now than in the last 1,000 years or that there has been any significant downward trend in temperature that might presage an ice age.
The Meterological Office gives advice to a wide range of commercial organisations, nationalised industries and official bodies in regard to future climate. The recent television programme and the associated newspaper articles were basically a subjective compilation from a wide range of sources and the Meteorological Office was not invited to provide profes- 442W sional guidance on the possibility of climatic change.