The latte sippers of the inner city may not be the communities most threatened by climate change, but the latest UN scientific assessment of global warming's impacts suggests they will not go untouched.

That is because the Intergovernmental Panel on Climate Change projects significant disruption to coffee production as the planet warms.

Leaked drafts of the report's food security chapter finds changes in rainfall patterns and the spread of plant diseases and pests would reduce areas where coffee can be grown. Under particular risk is the highly used arabica species.

While some places might become more suitable to grow coffee as the planet warms, the draft says in many cases suitable growing land will contract significantly with 2 to 2.5 degrees of warming. An overall decline in good coffee growing areas by 2050 was found in all countries studied.

If production does fall, Matt Perger - an Australian world champion barista - says that will likely have an impact on the prices paid by cafes and coffee drinkers.

But importantly Mr Perger, and the leaked drafts, say the real pressure will be felt by the millions of small landholder producers of coffee in Africa, Asia and Latin America. While some might be able to adapt to the changing conditions by moving farms to higher altitudes or cooler areas, and by growing under shade, that will not always be possible.

''If the farms that are up higher are the only ones that are producing coffee, then supply and demand dictates the price is going to go skyrocketing,'' Mr Perger says.

Mr Perger says warming average temperatures also have the potential to impact the taste and quality of coffee. Not too much is known, he says, ''but there is definitely a small range of temperatures that ripen coffee cherries exquisitely''.

Justin Hodgson, manager at Sensory Lab, a Bondi cafe that directly sources coffee beans from around the world, said he thought there may be some upsides for coffee beans production.

"There are terroirs that have never been tapped into before further south and further north because of this expansion of the tropic belt," Mr Hodgson said.

"So even though this truly terrible unfortunate thing is happening to our planet, it is opening up new areas for cultivation of coffee because of the very specific temperature and climate that it requires to grow," Mr Hodgson said, citing areas of Indonesia and Vietnam.

He said coffee production and prices were influenced by a range of complex political, economic and social factors and climate change would not cause higher coffee prices.