Several parts of the world may see temperatures exceeding "safe" levels in the next two decades unless emissions of greenhouse gas are substantially reduced, climate scientists warn.

According to two research papers published in the journal Nature, "Certain levels of climate change are very likely within the lifetimes of many people living now ... unless emissions of greenhouse gases are substantially reduced in the coming decades."

The study by academics at the English universities of Reading and Oxford, the UK's Met Office Hadley Center and the Victoria University of Wellington, New Zealand, points to Eurasia, North Africa and Canada as the areas that could potentially experience individual five-year average temperatures that exceed the 2 degree Celsius threshold by 2030.

Most parts of the world's land surface will likely experience five-year average temperatures that exceed 2 degrees above pre-industrial levels by 2060. This development can be delayed by up to several decades if the emissions are substantially lowered, the study said.

But even with reduced emissions, some regions will not be able to avoid warming and extreme weather events such as heatwaves.

Industrialized nations set a 2 degree Celsius warming as the maximum limit two years ago to avoid dangerous climate changes including more floods, droughts and rising seas.

Next month, nations will meet again for the next U. N. climate summit in Durban, South Africa, where a more binding pact to reduce emissions is expected to be reached, with many scientists believing that the present global pledges for curbing greenhouse gas emissions are not strong enough to prevent "dangerous" climate change.