Scientists have revealed that climate change has already impacted all of Earth’s ‘life zones’ and the effects are set to triple under business-as-usual emissions growth.
A University of Queensland and Wildlife Conservation Society-led (WCS) research team assessed the impact of global warming across the world’s 45 different ‘life zones’ – distinct biogeographic regions characterised by differences in temperature, precipitation, and aridity along with the species and ecosystems that live within them.
UQ’s Professor James Watson said all areas have undergone change since the early 1900s.
“We found that 27 million square kilometres, or 18.3 per cent of earth’s land mass had been impacted,” Professor Watson said.
“Fundamental shifts in these life zones have occurred most notably in boreal forests, temperate coniferous forests, and tropical coniferous forested systems.
“So, Canada, the United States, Russia and those in northern Europe have experienced some of the biggest changes.
“Boundaries between life zones have shifted poleward and towards higher elevations, leading to expansions of zones associated with tropical climates and contractions of zones associated with temperate climates.”
The research team also found that maintaining current 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,” Professor Watson said.
WCS Climate Adaptation Scientist Dr Paul Elsen said the predicted changes in the life zones are likely to substantially affect people’s livelihoods and biodiversity.
“Large areas of the world are getting hotter and drier, and this is already having an impact in these areas,” Dr Elsen said.
Professor Watson said the evidence that climate change has already impacted 20 per cent of the Earth’s landscapes should worry everyone.
“The accelerated pace of life zone changes will clearly challenge sustainable development strategies for humanity,” he said.
“These life zones provide the very ecosystem services humans rely on and when they change, like they are doing, we cannot rely on them in the way we have in the past.
“Services such as fisheries, pollination and clean water supply are going to change in dramatic ways.
“It highlights the importance of both reducing emissions as quickly as possible and planning for climate adaptation immediately.”
UQ and WWF-Australia’s Dr Michelle Ward said the findings highlight the critical importance of COP26.
“We need countries like Australia to show leadership in climate action,” Dr Ward said.
“Instead, Australia has been ranked last for climate action out of nearly 200 countries in the most recent UN Sustainable Development Report.”
The study has been published in Global Change Biology (DOI: 10.1111/gcb.15962).