"For example, across the studies reviewed the estimates of the increase in the tropics vary from 2.0 to more than 5 degrees of latitude approximately every 25 years. That makes the minimum agreed expansion of the Topics zone equivalent to around 300 kilometres.

"This variation of estimates makes predicting future shifts difficult. Estimates for the expansion of the tropical zone in next 25 years range from approximately 222 kilometres to more than 533 kilometres depending on which estimate is used," the review concluded.

The tropics currently occupy approximately 40 per cent of the Earth's land surface and are home to almost half of the world’s human population and account for more than 80 per cent of the Earth's biodiversity.

The majority of the world's endemic animals and plants, which are found nowhere else on earth, are found in the tropics and are adapted to the climatic conditions.

"Thus, the implications of a poleward expansion of the tropical and subtropical zones are immense and the effects could result in a variety of social, political, economic and environmental implications," the review said.