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High temperature taking toll on global biodiversity

New research covered more than 30,000 species around the world and found that for more than a quarter of the locations of biodiversity and ecosystems face an uncertain future…reports Asian Lite News

Exploring the implications of a multiple, decades-long temperature overshoot for global biodiversity, which is already affected by climate change, a new study has found that an overshoot like this is likely to cause major and, often irreversible, damage to biodiversity and ecosystems across the world.

With global climate action lagging behind the scale needed to achieve the temperature targets of the Paris Agreement — which calls for restricting the global temperature rise to preferably 1.5 degrees Celsius compared to the pre-industrial era — the scientists are studying several scenarios featuring a multiple decades-long ‘overshoot’ of the global warming limits set by policymakers. They then use carbon dioxide removal (CDR) technology to reverse dangerous temperature rise by 2100.

The new research, published in Philosophical Transactions of the Royal Society B: Biological Sciences, covered more than 30,000 species around the world and found that for more than a quarter of the locations of biodiversity and ecosystems across the world studied, the chances of returning to pre-overshoot ‘normal’ are either uncertain or non-existent.

The research team from the University of Cape Town (UCT) and University College London (UCL) explored the implications of a temperature overshoot for global biodiversity, which is already affected by climate change as warming causes mass die-offs in forests and coral reefs, alters species distributions and reproductive events, and many other parameters.

‘Several scenarios’ as mentioned above are the Representative Concentration Pathways (RCPs), a term for trajectory of greenhouse gas concentration (not emissions) adopted by the Inter-governmental Panel on Climate Change (IPCC) in its reports. The IPCC charts out multiple scenarios with a given temperature rise leading to a certain trajectory.

The paper explores an overshoot scenario where CO2 emissions keep growing until 2040, then reverse their course and fall into negative territory after 2070 thanks to deep carbon cuts and massive deployment of CDR. This means that, for several decades in this century, global temperature breached the 2-degree limit but returned to below this level around 2100.

The research team found that, for most regions, exposure to unsafe temperatures will arrive suddenly as further warming means many species will simultaneously be pushed beyond their thermal niche limits. However, the return of these species to conditions comfortably within their thermal niches will be gradual and lag behind the temperature decline. “In fact, the effective overshoot for biodiversity risks is projected to be almost twice as long as the actual temperature overshoot of around 60 years,” the study said.

Tropical regions are most affected by these risks, with over 90 per cent of species for many locations in the Indo-Pacific, Central Indian Ocean, Northern Sub-Saharan Africa, and Northern Australia pushed outside of their thermal niches. And in the Amazon, one of the most species-rich regions of the world, more than half of the species will be exposed to potentially dangerous climate conditions.

For about 19 per cent of the total number of sites studied, including the Amazon, it is uncertain whether the share of exposed species will ever return to pre-overshoot levels. And a further eight per cent of sites are projected to never return to those levels at all. This means that the overshoot, while reversing the course of global temperature, can cause irreversible impacts to nature due to species extinction and radical transformation of ecosystems.

The study underscores how important a temporal perspective can be in discussions of overshoot scenarios, which often dismiss the ‘journey’ of dangerously rising temperatures as long as the ‘final destination’ is within the agreed limits and thus may underplay rapid and deep emissions reductions called for in the recent IPCC reports.

Dr Joanne Bentley of the African Climate & Development Initiative (ACDI) at UCT said: “It is important to realise that there is no ‘silver bullet’ solution for mitigating climate change impacts. We have to rapidly reduce greenhouse gas emissions. Many carbon dioxide removal technologies and nature-based solutions, such as afforestation, come with potential negative impacts.”

“Our study shows that should we find ourselves overshooting the 2.0 degrees Celsius global warming target, we could pay dearly in terms of loss of biodiversity, compromising the provision of the ecosystem services that we all rely on for our livelihoods. Avoiding a temperature overshoot should be a priority, followed by limiting the duration and magnitude of any overshoot.”

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Urgent steps must be taken to save world’s third pole

The first draft of the post-2020 global biodiversity framework set a target of 30 per cent of terrestrial land being protected in 2030… reports Vishal Gulati

With the draft global biodiversity framework in preparation for the 15th meeting of the Conference of the Parties to the UN Convention on Biological Diversity (COP-15), Chinese researchers say comprehensive biodiversity monitoring programs are urgently needed on the Tibetan Plateau – the worlds “third pole”.

Talking to IANS virtually, Chinese researchers Lingyun Xiao and Li Li at Xi’an Jiaotong-Liverpool University talk about their work that deals with local communities on the plateau, which scientists believe is �melting’ fast and urging to take climate action now.

“In my opinion, comprehensive biodiversity monitoring programs are urgently needed in Tibetan Plateau to understand the status quo and to inform the developing of countermeasures,” said landscape ecologist Li.

However, there is a lack of data to assess climate change impacts on the biodiversity of the plateau, she remarked.

The Tibetan Plateau lies between the Himalayan range to the south and the Taklamakan Desert to the north. (Wikipedia)

Both researchers have done extensive research on human and nature interactions and the importance of involving local communities in conservation activities.

Lingyun, a field ecologist who focuses on wild mammal ecology and conservation, told IANS in an interview that the Tibetan Plateau is an important part of biodiversity conservation, although not entirely belonging to one of the global hotspots.

“It conserves the unique assemblage of large mammals, most of which evolved from the plateau. A group of archaeologist found an assemblage of mammal fossils on the plateau, all dated back to four million years ago, way before the ice age in Pleistocene.

“It suggest that the cold winters in rising high Tibet served as a habituation ground for the mammals, which became pre-adapted for the Ice Age and then successfully expanded to the northern hemisphere through the Holarctic region,” she said.

Lingyun admits they observed grassland desertification due to permafrost melting in the western part of Sanjiangyuan region on the Tibetan Plateau.

Without mincing words, she clarified that climate change and permafrost or glacier melting are out of her research area.

About biodiversity and climate change, she replied, “As different parts of the plateau experience different directions of climate change, I suppose the impact on biodiversity would also be different. Some species would benefit from the changing climate, such as those used to living in warmer areas, species turnover would happen but nobody could be sure whether the overall biodiversity will decrease or not.”

“Studies have been conducted mostly at the local scale from warming experiment, or at the regional scale from species distribution model projection.”

The first draft of the post-2020 global biodiversity framework set a target of 30 per cent of terrestrial land being protected in 2030.

Pastoral nomads camping near Namtso. (Wikipedia)

As China has already released the ecological red line policy which covers 25 per cent of land area, it becomes important to consider other areas which could provide multiple functions and take biodiversity conservation into account.

The Tibetan Plateau is a vast region, ecological patterns and processes vary a lot from place to place. For example, the plateau’s temperature, precipitation and land cover changes differ a lot.

Currently, there are 35 global biodiversity hotspots in the world. The eastern edge of the plateau belongs to the hotspot mountains of southwestern China, and the southern edge the hotspot of the Himalayas.

“The plateau’s conservation value is well acknowledged domestically,” said landscape ecologist Li.

The top three largest protected areas in China are all located on the plateau — Qiangtang, Sanjiangyuan and Kekexili.

The establishment of these large nature reserves is certainly valuable to protect the unique flora and fauna on the plateau.

“Our own research, however, found that the importance of China’s farmland for conservation has been neglected. Cultivated landscapes in China play a significant role to sustain the country’s avian diversity. The importance is even more pronounced when terrestrial protected area increases from 17 to 30 per cent under the post-2020 biodiversity framework,” she said.

She hoped the new framework would also provide guidance for biodiversity protection outside conventional protected areas — particularly to foster biodiversity-human coexistence in farmlands and even urban districts.

The Secretariat of the UN Convention on Biological Diversity (CBD) in July released the first draft of a new global biodiversity framework, to guide actions worldwide through 2030, to preserve and protect nature and its essential services to people.

Tibetan Buddhist stupa and houses outside the town of Ngawa, on the Tibetan Plateau.

At the virtual third meeting of the Open-ended Working Group on the post-2020 Global Biodiversity Framework that went into recess on September 3, delegates helped build political momentum to ensure the level of ambition needed to safeguard and put biodiversity on a path to recovery by 2030.

Delegates will continue their discussions during the resumed session in January 2022 in Geneva, where they hope to advance the framework in preparation for consideration at CBD’s next meeting of its 196 Parties at COP-15 in Kunming in China next year.

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