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At the current rate of deforestation, the world's rainforests could completely disappear in 100 years.

Most scientists suggests fewer forests means larger amounts of greenhouse gases in the atmosphere and an increase in global warming.

But a new study argues that relationship isn't as straightforward and that deforestation could in fact be cooling the planet.

At the current rate of deforestation, rainforests could completely disappear in a hundred years. A new study argues  that deforestation could in fact be cooling the planet rather than contributing to global warming

Researchers at Yale University claim the process is being driven by the transformation of forests into cropland causing a net cooling effect on global temperatures.

Deforestation over the last 150 years has reduced global emissions of biogenic volatile organic compounds (BVOCs).

BVOCs increase the atmospheric distribution of short-lived climate pollutants, such as methane, which have a warming influence on climate.

'Land cover changes caused by humans since the industrial and agricultural revolutions have removed natural forests and grasslands and replaced them with croplands,' said Nadine Unger, one of the researchers.

Researchers at Yale University claim the process is being driven by the transformation of forests into cropland causing a net cooling effect on global temperatures

'And croplands are not strong emitters of these BVOCs-often they don't emit any BVOCs.'

The researchers used computer modelling to calculate BVOC declines and found that there has been a 30 per cent decline between 1850 and 2000, largely through the conversion of forests to cropland.

This same conversion produced an overall global cooling of about 0.1°C.

However, the overall global climate still warmed by about 0.6°C, mostly due to increases in fossil fuel carbon dioxide emissions.

Professor Unger said the findings do not suggest that increased forest loss provides climate change benefits.

Instead she claims it underscores the complexity of climate change and the importance of better assessing which parts of the world would benefit from greater forest conservation.

Since the mid-19th century, the percentage of the planet covered by cropland has more than doubled, from 14 per cent to 37 per cent.

Since forests are far greater contributors of BVOC emissions than crops and grasslands, this shift in land use has removed about 30 per cent of Earth's BVOC sources.

Not all of these compounds affect atmospheric chemistry in the same way. Aerosols, for instance, contribute to global 'cooling' since they generally reflect solar radiation back into space.

That means a 50 per cent reduction in forest aerosols has actually spurred greater warming since the pre-industrial era.

However, reductions in the potent greenhouse gases methane and ozone — which contribute to global warming - have helped deliver a net cooling effect.

These emissions are often ignored in climate modelling because they are perceived as a 'natural' part of the earth system, explained Professor Unger.

'So they don't get as much attention as human-generated emissions, such as fossil fuel VOCs,' she said.

'But if we change how much forest cover exists, then there is a human influence on these emissions.'

This same conversion produced an overall global cooling of about 0.1°C. However, the overall global climate still warmed by about 0.6°C, mostly due to increases in fossil fuel carbon dioxide emissions