Droughts in the 1970’s
By Paul Homewood
Two droughts that have hit the headlines in recent years have been those in India in 2009, and Russia in the following year.
BBC had this to say about the Indian event at the time.
India suffered its weakest monsoon for nearly 40 years, the country’s meteorological department says.
Rainfall nationwide is 23% below average at the end of the monsoon season, making it the worst drought since 1972, officials said.
The following year, the Daily Telegraph reported on the Russian heatwave.
Much of western and central Russia is suffering through a severe drought, thought to be the worst since 1972.
And what was happening back in 1972? The Northern Hemisphere had been locked into a cooling trend since 1945, that HH Lamb describes as “the longest-continued downward trend since temperature records began.” At the same time, Kukla reported that “the area of snow and ice, integrated over the year across the Northern Hemisphere, was 12% more in 1973 than in 1967, when the first satellite surveys were made.”
Bryson, studying the Indian drought, found that :-
In the first quarter of the century, there was a severe drought in N and NW India every 3rd or 4th year. Then, as the Earth warmed up and the circumpolar vortex contracted, the monsoon rains penetrated regularly into Northern India, and drought frequency declined to 2 in 36 years, from 1925-60. But since 1960, with the cooling of the Earth and the southern movement of the subtropical high pressure areas, drought frequency has been increasing again and the probability may be now more than once a decade.
Bryson adds that if a drought frequency like that which prevailed at the start of the century were to occur now, with India’s population having increased by a factor of 4, the human and political consequences would be enormous.
Unquestionably, though, the most serious drought hit the Sahel, starting in 1968 and not ending until the 1980’s. Lamb reports that, during the most intense phase from 1972-74, between 200,000 and 400,000 died.
According to Lamb, “The subtropical anticyclones associated with the desert belt were displaced somewhat towards the equator, and the equatorial rainbelt seems to have been restricted in the range of its seasonal migrations. In consequence, rainfall increased in Africa close to the equator, causing the lakes to rise, while drought began to afflict places nearer the fringe of the desert belt, no longer reliably visited in summer by "equatorial" rains. “
He also identified the same pattern in the Southern Hemisphere. “There are indications that corresponding shifts have taken place in the anticyclone and cyclone belts of the southern hemisphere and that the droughts affecting Zambia, Rhodesia and parts of the Transvaal in recent years are essentially part of the same phenomenon.”
“At the same time, the shifting positions from month to month, and from one year to the next, occupied by the main anticyclone centres in this belt have introduced an abnormal variability of temperature and precipitation. A similar development may explain the sequence of droughts and floods in different parts of Australia in 1972-3. “
Next time someone tries to tell you that global warming causes droughts, just remind them about the 1970’s.
1) HH Lamb – “Climate: Present, Past & Future”
2) UNESCO – “The Courier”