Earth's "life zones" shifting due to climate change: Aussie researchers

Climate change is already altering the Earth's "life zones" and the effects are set to increase threefold within the coming decades due to continued growth of carbon emissions, according to a new study by Australian researchers.

The research team, in a study published in the Global Change Biology and revealed on Tuesday, assessed the impact of global warming across the world's 45 life zones, which are defined as being distinct regions characterised by differences in temperature, precipitation, and aridity along with the species and ecosystems that live within them.

Conservation scientist Professor James Watson from the University of Queensland (UQ) said the study found that about 18.3 percent of the Earth's landmass had already been damaged with the biggest changes occurring in boreal forests, temperate coniferous forests, and tropical coniferous forested systems in the northern hemisphere.

It means the boundaries between the zones have shifted poleward and towards higher elevations, leading to expansions of zones associated with tropical climates and contractions of zones associated with more temperate climates. Put simply, larger regions are getting hotter and drier.

Watson said the research was a warning that maintaining current carbon emissions rates would be potentially catastrophic.

"Business-as-usual may mean that climate impacts will triple in their extent across life zones in the next 50 years," he said.

"The accelerated pace of life zone changes will clearly challenge sustainable development strategies for humanity. These life zones provide the very ecosystem services humans rely on and when the zones change, we cannot rely on them in the way we have in the past."

The researchers said some of the diverse impacts would include the dramatic deterioration of fisheries, pollination, and clean water supplies.

"It highlights the importance of both reducing emissions as quickly as possible and planning for climate adaptation immediately," Watson said.