The famine numbers provided by both Deng Xiaoping's government and Western academics are criticized for coming from heavily biased sources, the unreliability of the given evidence, and the atypical procedures that were used to calculate them. In regards to the numbers released by Deng's regime, there seems to be no way of independently authenticating these figures due to the great mystery about how they were gathered and preserved for twenty years before being released to the general public. Mao even said himself that there were some policy errors that contributed to the famine, but said that weather and natural disasters were largely to blame. The following excerpt is from an article published by the China Study Group in 2003:

Jimo County, one of the worst hit places in the whole country, suffered spring draft and summer floods for three consecutive years. On June 30, 1958, a ten-hour rainstorm with a precipitation of 249 mm caused 22 rivers to overflow and wrecked 69 dams and reservoirs. On June 15, 1959, intense rain damaged 75,900 mu crops, wrecked 4,629 houses and killed 8 persons. In summer of 1959, there was a locust breakout in five communes that ruined 18,584 mu crops. On May 27, 1959, a hailstorm ruined 31,000 mu crops of five communes in west of Jimo County, causing an estimated grain loss of 1.35 million kilos. On July 27, 1960, a hurricane attacked the whole county, ruining 777,000 mu of crops. On August 17, 1961 a rain storm with a precipitation of 230 mm in three hours flooded 280,000 mu crops. On top of that, there were also other minor natural disasters. These natural disasters, compounded by other problems, caused severe grain shortages in Jimo County.

But we should put this into context. According to Guo Shutian, a former Director of Policy and Law in the Chinese Ministry of Agriculture, during the period of Mao's leadership (1949 to 1976), the per hectare yield of land sown with food crops increased by 145.9% and total food production rose 169.6%. During this period, the population of China grew by 77.7%. Even by the Deng regime's numbers, there was positive growth in many facets of society, like industrial production. Furthermore, famines are cyclical in China, and there have been famines throughout its history that have caused the deaths of far more people than the 30 million that the famine under Mao supposedly killed.

But what's more problematic than the dubiousness of the numbers commonly thrown around to describe how many people were killed in the Chinese famine of the mid-20th century, is the lack of awareness of the bigger picture of the Chinese revolution and Mao's true legacy. See this comment.